Need Advice - Lennox GWB8-105S boiler - Low Heat Output


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Old 12-15-10, 10:04 PM
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Need Advice - Lennox GWB8-105S boiler - Low Heat Output

Need advice on Lennox GWB8-105S boiler (approximately 7 yrs old) in house I purchased this spring. The unit doesn't seem to be putting out the heat it should.

The boiler is rated at 105,000 Btuh (input), 85,000 Btuh (output), 74,000 Btuh (Net I=B=R); 80.4% AFUE. Copper tubing baseboard heat. Single zone.

The house is brick construction built in 1961, is 1100 sq. ft., single story with a full unfinished basement (basement is not heated). The first floor sets about 3 feet above ground level, meaning the basement is partially above ground. Basement is concrete blocks with concrete slab floor. Windows are original, single pane with storms. All in good shape (normal wear and tear) with no air leakage noted. Windows in 3 bedrooms are awning windows (north and west side of house) with tight fitting storms, producing a double pane effect. I've covered the internal screens in the bedrooms with insulating plastic and lined the window frames with polyfoam weatherseal to produce a snug, relatively leak free fit for the screens. Windows in kitchen and dining area are typical double hung with aluminum storms. Living room Window is a large picture window with 1/2 width double hung windows on each side, but front of house has an unheated glass enclosed porch so there is no direct exposure to weather on the living room windows. Attic is insulated. House has A/C installed in the attic. House is located in an old city neighborhood in upstate NY with high density lots (30 to 45 feet lot widths), so exposure to wind is minimized by housing and full growth trees.

We recently had our first cold snap/snow storm with temperatures in the teens and a wind chill factor of around zero degrees. The internal house temperature would not rise above 67 degrees during this 4 day cold snap. Even with the temperature subsequently rising to the high teens/low twenties, the house would not get warmer than 71 degrees internally.

I called the outfit that installed the boiler unit to come and do maintenance on it. They indicated the water in the system was low, the pipes needed to be bled of air, and that most everything else seemed to be in order. The unit is now running at 175 degrees with circa 18 PSI. After the maintenance the house seemed to get about 1 degree warmer in under 20 degree weather.

I've been told locally that a general rule of thumb for furnace sizing around this area is 40 Btuh per sq. ft of heated space. Based on that rule of thumb, a 40,000 Btuh unit should suffice to heat this 1100 sq. ft. house? With 74,000 Btuh (Net I=B=R) rating on this unit, I'm having a hard time figuring out why it can't heat this house any warmer than it does.

If we get a below zero cold snap, the internal temperature of this house is going to be 60 degrees or colder. Not exactly what I envision for paying the cost of running this boiler full blast.

Does anyone have any suggestions as to what the cause of this low performance might be? I'd really appreciate any suggestions - before I freeze to death :>)
 
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Old 12-15-10, 10:36 PM
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Is the boiler firing constantly to maintain that 175 degree water temperature or is the burner cycling on and off? If the latter I would lean towards not enough heat emitters were installed for operation at 175 degrees. You can try adjusting the water temperature up to 190 degrees and see if that helps.

If you need help on how to adjust the water temperature then take a few pictures of the boiler and controls and post them. To post pictures you need to first upload the pictures to a photo hosting site such as photobucket.com or villagephotos.com. and then post the public URLs for the pictures (or album) here. More pictures are always better than fewer. Please have CLEAR, in focus and well lit pictures and have both close up pictures and ones from a far enough distance that we can see how the various parts are interconnected.
 
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Old 12-15-10, 11:09 PM
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I'm new at this boiler stuff, so excuse my beginner questions please. I'm not sure what you mean by "boiler firing constantly" or "burner cycling on and off". What is the difference? As far as I can tell, every time I check the boiler its running, i.e. I can hear the burner. How do I tell if the boiler is "firing constantly"?

I also replaced the original mercury thermostat with a Honeywell RTH2300, and set the "heating cycles" to 2 (lowest value available). Wouldn't that interaction affect how often the boiler runs (fires?).

I'll take some pics and post. Might take a day or two. Left my camera at girlfriend's house last weekend :>(
 
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Old 12-16-10, 12:54 AM
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Here are pictures of my boiler setup. (Found an ild camera :>) Hope this works. Its the first time I've done this.









 
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Old 12-16-10, 01:52 AM
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The picture of the thermometer indicates 190 degrees F. and the pressure is about 15 psi assuming there are no gross errors in the gauges. The temperature is fine or maybe a little high and the pressure may be a little low. Do you hear any kind of "sloshing" noises (water in the pipes) at the baseboard heaters?

If you do hear the water then you most likely have air in the piping and that can impede or completely stop the flow of water through the heaters. Because I see a "purge" valve on the return piping (the valve with the garden hose connection) I am assuming that you do not have any air vents on the baseboard convectors (heaters) themselves but please remove some end covers from the baseboards (they should just snap on and be removable by gently prying up from the bottom with just hand pressure) and take pictures of the fittings. I don't see any kind of "air removal" device either and that could be a part of your problem.

If you are hearing noises in the piping try this: The horizontal pipe going across the boiler that has the "bell-shaped" fitting has a handle on it, try lifting that handle to add more water to the system while watching the pressure gauge. lower the handle when you get about 18 to 20 psi showing on the gauge. Don't go any higher than 20 right now. Next, hold a can under the pipe nipple coming from the safety valve (located above the tee fitting that goes to the grey expansion tank) and gently lift the lever on the safety valve. You should get an instant flow of water but you may get a burst of air before the water. As soon as any water is released let go of the lever. Check the pressure again and if necessary do the lever on the bell-shaped fitting to raise the pressure to between 15 and 18 psi.

There are some things about the installation of the boiler that are just plain wrong but nothing that should keep it from properly heating your home. Please post back with the results of these actions.
 
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Old 12-16-10, 07:47 AM
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I don't hear water gurgling in the pipes since I had the maintenance done. And there is an air removal device attached to the piping up toward the ceiling - didn't get that in the picture :>( There are no air vents on the baseboard heaters. I checked. Just copper tubing running straight into the baseboard fins.

Once in awhile I can hear what sounds like water running through the pipes, but only in the bathroom and one rear bedroom (the two rooms being side by side). Its not consistent or predominant and seems to have diminished over time, since the maintenance was done.

Given the aforementioned, I have not undertaken the actions you suggested.

I do occasionally hear (from the basement in the general location of the boiler) what sounds like someone hitting a metal pipe with a hammer. Its not overly loud, but it echos, like the sound effects in old submarine movies. It happens once, then doesn't happen again for several minutes, or even hours (that I notice anyway).

I'd appreciate you observations on what may have been done incorrectly on this installation. I'm beginning to think that my problem may be a 'component design' issue, rather than a boiler problem per se, since the boiler itself appears to be operating as designed to operate.
 
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Old 12-16-10, 03:58 PM
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I don't have much to add... only a comment about the wiring.

I'm always puzzled when I see coils of MC cable looped around like that. What, did they not know how to shorten that cable? What's the point of leaving six extra feet of cable? A roller coaster for the electrons?
 
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Old 12-16-10, 03:59 PM
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sounds like someone hitting a metal pipe with a hammer.
Almost no doubt that what you are hearing is expansion/contraction of the heat emitter piping.
 
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Old 12-16-10, 04:14 PM
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What's wrong with it you ask?

1. The plastic 'Romex' (NM) wiring should not have been used. But given the fact that they apparently don't know how to work with it, I guess I can understand why they didn't use the MC cable... or EMT.

2. No expansion tank should ever be hung on a branch of piping without secondary support. ESPECIALLY on the water heater tank, using copper piping. The weight of a failed expansion tank full of water is substantial. There should be support at those points up to structure.

3. The pressure relief valve should be piped to within 6" of the floor, and there should be NO THREADS on the bottom of the pipe in order that it can NOT be capped.

4. I'm not at all happy with the way the LWCO is mounted.

5. I think this has been mentioned... there is no PROPER air removal device in sight!
 
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Old 12-16-10, 04:25 PM
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I didn't answer your question about burning continuously or cycling. Your boiler is heated by a gas burner flame underneath and it will "cycle" (turn the flame on and off) to maintain a set temperature. If the burner is on constantly it is a sign that the boiler is undersized for the heating load (something I very seriously doubt in this case) or that there is something seriously wrong with the burner itself. In either case there would be a corresponding drop in the temperature of the water contained in the boiler.

If the burner is cycling on and off while the circulator pump (the black object piped on the side of the boiler) continues to run constantly then there is a problem in getting the heat from the boiler to the house.

I'm going to give you a real quick "Hydronic heating 101" on how your system should operate. The boiler and associated piping contain a quantity of water that is heated by a gas flame. The circulator pump will move that water through the piping to the heaters in the living spaces when the room thermostat "calls for heat". That call for heat actuates a low-voltage relay in the grey box to the right of the circulating pump and when the relay is actuated it starts the pump AND allows the burner to fire.

Note that the burner will not fire unless the pump is running and the pump doesn't run unless the room thermostat is calling for heat.

Now that the thermostat is calling for heat, the relay has closed the electrical circuit to the pump and enabled burner operation the burner is under control of a thermostat immersed in the boiler water. This thermostat is called an aquastat and is also contained in the grey box that holds the circulator relay. The aquastat has a "hi-limit" setting that turns off the gas to the burner when the boiler water reaches the set temperature. There is also a "differential" setting (some aquastats have adjustable differentials and others have a fixed differential) that will turn on the gas to the burner when the boiler water temperature drops some specific amount from the hi-limit temperature set point. The differential temperature is generally about 20 degrees but it could be more or less in any specific system.

The gas burner has an electrically operated valve (lower left corner below the circulating pump) that is opened or closed under control of the aquastat and circulating pump relay. Some boilers have electrically lit burners but yours has a constantly burning "pilot" light, referred to in the industry as a "standing pilot. To prevent a dangerous situation if the pilot light were to go out there is a safety device built into the gas valve that uses a sensor in the pilot flame that tells the gas valve to close the pilot function if there is no pilot flame.

There are other safety devices and operational devices on your boiler that I will ignore for the time being but are necessary for a safe operation.

I mentioned some installation irregularities and I will detail them now. None of these are the cause of your current problem and some are more personal dislikes rather than real problems.

1. The power cable from the house electrical to the aquastat controller (the grey box on the side of the boiler) is currently type NM cable. This is not in keeping with the National Electrical Code (NEC) and it should be a flexible conduit or armored cable as is used between the aquastat and circulator. This same type NM cable is being used between the aquastat and the low water cutout (LWCO, the black box located above the aquastat and inserted into the supply pipe). The extra armored cable between the aquastat and the circulator is just poor workmanship.

2. The safety valve has a nipple and elbow coming out of the discharge opening and then a six-inch nipple pointing downward. This six-inch nipple should instead be a piece of pipe extending down to within six inches of the floor.

3. I don't like the placement of the expansion tank on the boiler, it really should be on the suction side of the circulating pump, preferably between the return piping and the make-up water pressure regulating valve (PRV).

I also don't like the supply (boiler outlet) piping coming out of the side of the boiler as it will cause air to become trapped in the boiler. The ideal outlet would have been either the tapping for the safety valve or the pressure gauge although it is possible that the manufacturer did indeed specify the arrangement used.

So, post back telling me how long the burner fires and how long the burner off cycles are and we can look further into your problem.
 
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Old 12-16-10, 04:30 PM
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The LOW OUTPUT issue:

What type of heat emitters are in the home? (sorry if it's been asked and answered and I missed it)

If fin-tube baseboard, remove the covers, get out the vacuum cleaner and a brush and clean the fins of any accumulated dust, pet hair, spider webs, etc... you will be amazed at the extra heat that will come out. A small coating of dust is enough to make a very noticeable difference in the heat output.

It appears as if the piping to and from the heat emitters is 3/4". Technically speaking, this size piping is only good for moving about 40,000 BTU of heat. Your boiler is TWICE as big as it needs to be for this distribution system. You should have NO PROBLEM heating the home.

Let's go back to the heat emitters... how are they piped? Does the pipe from the boiler go first up and into the baseboards/radiators, and then come back down, then up into the next, then back down, etc, etc ? A SERIES LOOP ? Or some other arrangement? Can you take some pictures how they are connected together?

Can you give us a link to your PUBLIC photobucket album so that we can browse through the full size pictures ?
 
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Old 12-16-10, 09:52 PM
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Thanks for the education! I do like to conceptually understand something like this before I start messing around with it :>)

Here's a link to my PhotoBucket Album. The original pics are shot at 3 megapixel. Hope that will be detail enough. Furnace Pictures

Now I'll try to answer questions.

NJ Trooper:

The emitters look to me to be what you refer to as "fin-tube" emitters (I've added a picture to PhotoBucket). I gave them a 'hands and knees' cleaning when I moved into the house in June of this year (they were a mess), and I vacuum them probably once every month or two. The louvers on the emitters have been removed (never were installed), so I guess I'd better get in the habit of vacuuming them whenever I vacuum a room.

The piping to and from the emitters is 3/4" copper piping, as you surmised from the pictures. The piping runs in a single loop around the perimeter of the basement, i.e. it is a series loop. I note the water in the piping seems quite warm even on the return pipe.

Furd:

I tracked 3 cycles of the boiler. The burner kicks in at 180 degrees as the water temp drops. The water temp keeps dropping to 170 degrees, then starts to climb. When the water temp rises to 185 degrees, the burner stops. The burn time is roughly 3 to 3 1/2 minutes. After the burner stops, the water temp continues to rise up to 195 degrees, then starts to drop again. The cycle starts over again when the water temp drops back down to 180 degrees.
 
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Old 12-16-10, 10:14 PM
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I hate to tell you this but I think that you may have a bum system. The 3/4 inch piping is bad enough but having a series loop is probably the killer and you may be rather deficient on the total length of baseboards.

When you vacuumed the baseboard convectors did you remove the front covers? Is there (maybe) wall-to-wall carpet somewhat obstructing the air inlet to the bottom of the baseboard convectors? They must have an unobstructed air inlet of at least an inch in order to work properly.

I still want you to raise the pressure to slightly above 15 psi and then see if any air comes out when you lift the test handle on the safety valve. If air does come out repeat the pressure increase and air release until it is solid water and then raise the pressure to a minimum of 15 psi when at operating temperature.
 
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Old 12-17-10, 08:42 AM
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After the burner stops, the water temp continues to rise up to 195 degrees
This statement has got me wondering...

Let me first clarify that at this time, your heat call is continuuing, and the circulator is STILL RUNNING... yes?

To get that much 'heat soak' after the system hits high limit and the burner shuts down, WITH THE CIRCULATOR STILL RUNNING, I can't imagine that you have enough flow in your system... in fact, it almost makes me wonder if the circulator is running at all...

Can you get us a close-up of where the LWCO is connected to the pipe? I'm wondering if that's presenting an obstruction to the flow...

OR, maybe that obstruction to flow is still air in the boiler (as furd is suggesting), or an air blockage in the system piping...

How many total feet of fin tube ELEMENT (not the pipe, just the part that has the fins) are installed in the home?

The idea that you may not have enough emitters installed has some merit... but at 1100 sq ft I can't imagine that your heat loss is above say 35000 BTUH and the 3/4" piping should suffice. You should probably have around 65' of fin tube element installed throughout the home.

OH, you said the pipes were WARM ? at 180 degrees, you should be saying that they are BLAZING HOT! you should not be able to hold your hand on them for more than an instant... to me, WARM is like 120-130 degrees, and you would be able to hold onto that for a few seconds... at 180 your hand should recoil almost instantly from pain.
 
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Old 12-17-10, 09:09 AM
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Furd:

No wall to wall carpeting. All hardwood floors and linoleum.

The baseboard elements are more than sufficient, I'd think. I didn't measure them but each of the smallish bedrooms has 1 element each, about 8-9 feet in length I'd say. The living room element wraps around a front and side wall of the house, with 9' or 10' on each wall. The kitchen element/dining room element is probably 9 - 10 feet in length. There are 2 small elements in the bathroom, each between 2-3 feet.

The PSI is already at 15. I've located the safety valve (in my pic I believe its got the green tag hanging on it). But I'm not sure how one would "raise the pressure" or lower the pressure again to get it back down to 15 PSI afterwards.
 
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Old 12-17-10, 09:28 AM
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Just my 2 cents.

3 1/2 minute burn time seems very short.

The baseboard in the pic looks like the old high output stuff we used to in stall. Its probably stealing alot of heat.

Sounds like the circ might not be running.


Mike
 
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Old 12-17-10, 10:21 AM
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I think it is definitely a circulation problem and the way that boiler is piped it can have a huge amount of air above the water outlet.

Yes, the safety valve has a green tag on it and is located at the back right-hand corner when facing the side of the boiler with the circulating pump. Hold a coffee can or something under the pipe nipple and wear gloves when you do it because the water is HOT! To raise the pressure in the system (by adding water) you need to raise the handle on the pressure regulating (automatic fill valve) located on the smaller horizontal pipe crossing over the top of the boiler, to the right of the vent stack.

Be careful when lifting the safety valve handle.

I need to go out on a house inspection but I will return this afternoon,
 
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Old 12-17-10, 10:28 AM
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If this helps any, the DUNKIRK PWB boiler is EXACTLY the same boiler except for the color (it's blue). So perhaps this I&O Manual will be helpful...

http://www.ecrinternational.com/secu...cument/385.pdf

It does show the side outlet as the supply, and the relief valve port at that location.

It also shows of course that the system should be set up with the pump on the supply side out, but that doesn't mean that it won't work with the pump on the return as installed.

Mike,
Its probably stealing alot of heat.
say what?
 
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Old 12-17-10, 10:35 AM
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The highoutput stuff gave off like 25% more btu's.
 
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Old 12-17-10, 10:39 AM
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Sure, I understand that, but what do you mean 'stealing heat' ? If it has a higher output, that's fine, but 'stealing' ? from whom/what ?
 
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Old 12-17-10, 10:42 AM
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NJ Trooper

Let me first clarify that at this time, your heat call is continuing, and the circulator is STILL RUNNING... yes?
ANSWER: I'd say yes. The house temp was at 69-70 and I set the thermostat up to 73 before I monitored the cycling. I assumed that would keep the aquastat controller "on call". I could hear a constant noise from the boiler that I assumed was the circulator running. Then, additionally, I could hear the burner kick on and off, while the other noise continued.

Can you get us a close-up of where the LWCO is connected to the pipe? I'm wondering if that's presenting an obstruction to the flow...
ANSWER: Yes, but probably not till tomorrow (Saturday).

How many total feet of fin tube ELEMENT (not the pipe, just the part that has the fins) are installed in the home?
ANSWER: My guesstimate on element footage for the house comes very close to your 65 foot number. (see my last response to Furd)

OH, you said the pipes were WARM?
ANSWER: Yes, I'd say warm. I wouldn't try holding my hand on them too long :>) But not blazing hot by any means. I can definitely hold my fingers on them long enough to tell that the outflow pipe is warmer than the return pipe (I'm assuming here that the hottest pipe is the outflow pipe.)
 

Last edited by NJT; 12-17-10 at 03:01 PM.
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Old 12-17-10, 10:52 AM
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Okay, that will get the PSI up. But how do I get it back down again, or stop it from rising if it starts getting too high? Just keep the safety valve open until the PSI drops to where I want it to be (circa 15 PSI)?

Originally Posted by Furd View Post
I think it is definitely a circulation problem and the way that boiler is piped it can have a huge amount of air above the water outlet.

Yes, the safety valve has a green tag on it and is located at the back right-hand corner when facing the side of the boiler with the circulating pump. Hold a coffee can or something under the pipe nipple and wear gloves when you do it because the water is HOT! To raise the pressure in the system (by adding water) you need to raise the handle on the pressure regulating (automatic fill valve) located on the smaller horizontal pipe crossing over the top of the boiler, to the right of the vent stack.

Be careful when lifting the safety valve handle.

I need to go out on a house inspection but I will return this afternoon,
 
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Old 12-17-10, 11:02 AM
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I'd guess you've written more than a few "specs" in your lifetime :>)

Originally Posted by NJ Trooper View Post
Sure, I understand that, but what do you mean 'stealing heat' ? If it has a higher output, that's fine, but 'stealing' ? from whom/what ?
 
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Old 12-17-10, 11:32 AM
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Well I saw a one loop system installed and the plumber put all highoutput baseboard at the front of the loop. He said he got it for free from another job. The baseboard at the end of the loop never really got hot. The t stat was in one of the three rooms with this type baseboard. Stealing heat? Thats what I meant by that. Should have been two zones probably. The guy never did a proper heat loss and just threw what ever he had on it.

Does it make sense?? It may not even be high output baseboard. It looks like it, but I only brought it up from something I saw in the past. Thats all.
 
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Old 12-17-10, 03:22 PM
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Phill, thanks for the answers...

Don't worry about the close-up of the LWCO, I can see it clearly in the pictures you've already uploaded. It is definitely NOT the proper way to mount that device, but I don't think it's contributing to your circulation problem to the extent that it would prevent circulation.

I could hear a constant noise from the boiler that I assumed was the circulator running.
If it is true that the circulator is running, and:

not blazing hot by any means. I can definitely hold my fingers on them long enough to tell that the outflow pipe is warmer than the return pipe (I'm assuming here that the hottest pipe is the outflow pipe.)
AND the water temperature in the boiler is running between 170 and 195, you most definitely would not (should not, unless you have 800 pound gorilla hands) be able to hold your finger on those pipes for more than a VERY short time! Think about how far that is from boiling... how long could you hold your fingers in boiling water? Not long! OUCH!

I'm reasonably convinced that the problem is a circulation one... that you have a significant amount of air trapped in the system that is preventing full circulation. So here is what I would like you to do:

Referring to this image:



See the blue handle drain valve on the return pipe coming down from the ceiling. See also the yellow handle valve below that. Also, see the handle on the pressure reducing valve to the right and tee'd off that pipe.

TURN THE BOILER OFF AND ALLOW TO COOL TO 100F OR LESS! YOU DO NOT WANT TO CRACK YOUR BOILER BY FEEDING COLD WATER INTO A HOT BOILER!

1. Connect a drain hose to that blue handle valve and direct to a drain, laundry tub, or out a nearby window. You will get a pretty fair amount of water flowing... a small bucket will NOT do.

2. CLOSE the yellow handle valve.

3. OPEN the blue handle valve all the way, and at the same-ish time;

4. PULL UP on the handle on your pressure reducing valve.

This will force water at the maximum flow rate through the boiler, up the supply (outflow) pipe, through the zone, and out the drain.

5. CONTINUE to hold the handle up until you see no more air exiting from the hose.

When you believe that all the air is out:

6. Let the handle on the pressure reducing valve back down, and:

7. CLOSE the blue handle valve.

8. OPEN the yellow handle valve.

===========================

You may now turn the power to the boiler back on and initiate a call for heat. Let it run up to high limit and tell me if you can still hold on to those pipes... and that you still don't have heat in the home... I'm hoping that you can't.
 
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Old 12-17-10, 04:00 PM
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The above process is only a temporary stop-gap solution at best. Hopefully it will get you through the winter... next spring think about re-doing some of the piping...

If it turns out that after this process you do have heat in the home, it will have proven that the problem was air trapped in the piping.

If NOT, we'll continue to hash out ideas... maybe the circulator... (I personally doubt it).

If this DOES work, let's talk about some suggested changes to the piping... (in addition to or coincident with the other suggestions already made. (my post #9, and Furd's post #10))

Solution 1. This 'solution' leaves the circulating pump on the return side.

On the SUPPLY (outflow) pipe... I would remove that vertical section of 3/4" copper, the reducing bushing, the tee that the LWCO is mounted in, and replace it with a 1-1/4" black steel pipe nipple, a 1-1/4" black steel tee with a 3/4" side port, another 1-1/4" black steel nipple, and a 90 black steel tee. On the TOP of the tee, pointing UP I would install a boiler drain valve for use as a purge valve. From the side of this tee, I would reduce to 3/4", and install a ball valve for service isolation purposes. You may be able to find a tee that has 1-1/4" on one end, and 3/4" on the other end and on the side port. Make sure that the nipples are long enough so as to allow removal of the top boiler cover for servicing. ( I would actually raise it a bit higher than it currently is.)

The LWCO would now mount in that 1-1/4" tee in the new supply 'riser'. (and be wired into the aquastat with the proper MC cabling)

Remove the expansion tank from it's current location. Re-install the pressure relief valve directly to a nipple on that port, and properly pipe to the floor.

Remove the vertical section of return piping from the valve above the pump, up to the ceiling. Remove the air vent at the ceiling. Retain the section with the drain valve and the yellow handle valve. You can re-use this.

Replace that vertical section of removed pipe with a 1-1/4" black steel nipple. Put a 90 black elbow facing to the left (in the pics). A short black nipple, a SPIROVENT air removal device (or similar), another nipple, an elbow pointing UP, and THEN reduce to the 3/4" copper and install the section with the drain and yellow handle valve and reconnect to the return from the house.

On the bottom tapping of the Spirovent, (top to bottom order) install a 1/2" nipple, a 1/2" ball valve, a 1/2" tee fitting (to connect the water fill line to), another nipple, another 1/2" tee fitting (to install a service drain), and screw the expansion tank into the bottom of that.

In lieu of all this stuff hanging on the bottom of the Spirovent, you could use a Watts RBFF and accomplish the same with less parts:




images courtesy watts.com

That's what I would do... just sayin'
 

Last edited by NJT; 12-17-10 at 04:20 PM.
  #27  
Old 12-20-10, 06:51 PM
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NJ Trooper:

Sorry it took so long to get back on this. I ended up away for the weekend.

I just tried bleeding the air from the system as suggested in your post #25. I've turned everything back on, and I'm waiting for the boiler system to heat up again. I have to say though that I saw absolutely no air coming out of the drain hose. Just smooth flowing, clean water. I let it run for awhile, since I had it all connected anyway. But I have my doubts that this will be solving the low heat output problem. Its in the twenties now, so its hard to judge whether the problem has been solved or not - unless I pump it up maybe and see just how high I can get the temp to rise.

I tracked 3 cycles of the boiler again. Total cycle time is between 7-8 minutes, burn time is between 3 and 3 1/2 minutes. 180(burner on), 170(water temp starts to rise), 185-188(Burner off), 195(water temp starts to drop).
 
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Old 12-20-10, 08:01 PM
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If there was no air blockage, then somehow else you aren't getting flow. If you had the flow you need, 185 degree water, you would definitely call those pipes RED HOT...

When you did the bleed/purge, you pulled the lever on the pressure reducing valve all the way up, right? didn't just let it feed at the slowly 'normal' rate, right? You need a good fast flow sometimes... and you had the yellow valve below the blue drain CLOSED (handle perpendicular to the pipe) , right?
 
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Old 12-21-10, 05:05 AM
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Yep. All as you describe. Had it wide open. A good flow through the pipes. I let it run for maybe 15 minutes. After firing the boiler up again, everything was like it was before purging. I turned up the thermostat to 80 degrees before going to be last night. This morning the internal temperature is hovering between 72.5 and 72.8 degrees. That's as warm as it will get. I'm using a table top thermometer to measure actual internal temperature at the table in my dining area. The Honeywell thermostat says that its 74 degrees in the house. I replaced the original Honeywell mercury thermostat with a Honeywell electronic thermostat (it was a 2 wire setup). Could the electronic thermostat be a problem for the boiler? I read somewhere that the Honeywell mercury thermostat has an internal attentuator(?) preset to 1.2, while the Honeywell electronic thermostat has a cycle setting that will not go any lower than 2.

Could the circulator be too weak - wrong sized?
 

Last edited by phillfri; 12-21-10 at 05:08 AM. Reason: Added Thought:
  #30  
Old 12-21-10, 03:45 PM
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Could the electronic thermostat be a problem for the boiler? I read somewhere that the Honeywell mercury thermostat has an internal attentuator(?)
I'm sure the thermostat is fine. If the system comes on when the thermostat calls for heat, it's working.

The 'attenuator' you are referring to is the 'ANTICIPATOR', and that is likely not the issue here either.

You've got HOT water in the boiler... and it's not getting out to your baseboards for whatever reason.

Could the circulator be too weak - wrong sized?
No, that circ [ IF it is working properly ] is fine for the job.

You say you hear a 'noise' when there is a call for heat... and I would guess that what you hear is the motor on the pump running... and if the motor is running there is little reason I can think of why it would not pump... but maybe the thing to do is verify that it is at least getting power, and most likely running...

Do you own a multimeter and know how to use it?
 
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Old 12-21-10, 04:00 PM
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Taco's FAQ for their wet-rotor pumps says that sometimes the rotor may stall due to build-up of deposits on the cartridge or the can. If there were something stuck in the impeller, that too could keep it from turning. You've got shutoff valves on both sides of the pump - easy enough to pull the cartridge and inspect it.

When the pump starts, assuming it runs, you should be able to detect the pressure gauge needle moving slightly, one way or the other.

If the rotor is stuck, I could visualize the motor still humming.
 
  #32  
Old 12-21-10, 04:45 PM
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True... I would check that the pump is getting power first though...

but yeah, the valves are there, it really is an easy matter to pull the pump.

And a new 007 can be had for around $60 if you shop on line... Pex Supply I believe had them 'on sale' recently. It might be worth it to simply swap the pump out and see what happens.
 
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Old 12-21-10, 07:56 PM
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I left the thermostat on 80 all day and when I cam home this evening the internal house temp was hovering between 73.5 and 73.8 degrees (based on my table thermometer). So it climbed 1 degree in roughly 12 hours. (Outside temp is still in the twenties day, high teens at night, little wind.)

I did notice something that seemed a bit peculiar when I fired the boiler up after purging. After waiting for the boiler to cool off and doing the purge, the house internal temperature had dropped to 66 degrees. When I fired the boiler up, I noticed that the house temperature went from 66 to 69 degrees in short order - maybe 20-30 minutes. After hitting 69 degrees, temperature rise slowed to a crawl, taking all night to get to 72 degrees and then another 12 hours to get to 73 degrees. Its almost as if the system is sitting there and mostly spinning its wheels after it pushed the temp up to 69 degrees. Does this give us any clues?

The pump is definitely running. I can feel it vibrate. And I could previously on occasion hear water flow in the first baseboard radiator in the loop; the bathroom. (That was before I had the boiler serviced.) But it seems to me that if the pump weren't working at all, I wouldn't be getting the surge of heat that I saw when I re-fired the boiler after purging it (66 to 69 in circa 30 minutes). I don't have a multimeter nor know how to use one - not that I couldn't get one and figure it out if that is necessary.

Another Thought: My basement is not heated, nor is my copper piping insulated. Might I be losing heat simply via dissipation throughout the loop?
 
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Old 12-21-10, 08:16 PM
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Another Thought: My basement is not heated, nor is my copper piping insulated. Might I be losing heat simply via dissipation throughout the loop?
You wouldn't actually be 'losing' heat, it's still going into the home, but the exposed pipes won't lose enough heat to make that drastic a change.

I'm actually out of ideas... other than going around and double triple checking that there aren't any closed valves ... absolutely verify that the baseboards are in fact piped in series and NOT MONOFLO fittings.... I just don't know what else to tellya.
 
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Old 12-21-10, 08:20 PM
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I AM still very leary about the way that LWCO is installed. I wouldn't be surprised if that probe is partially obstructing the flow. If you DO decide to remove it, please cover the aquastat with plastic! You don't wanna dump water on that.
 
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Old 12-21-10, 08:31 PM
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One unrelated side note... one of the pics in your album shows the supply pipe going up along the chimney to the ceiling... and it looks like it's actually in contact with the concrete... over time, with expansion and contraction, that concrete WILL eventually wear a hole in that pipe... so you might want to put something between the concrete and the pipe to prevent rubbing... if it is actually rubbing and not only camera angle...

Would you take some more pics please? Let's see the entire supply pipe until it disappears into the ceiling. Follow it as far as you can.

Look around the ceiling of the basement and see if you can locate any piping that drops down from the ends of the baseboards, over and back up again to the next one... and photograph them just for ha-ha's ...
 
  #37  
Old 12-21-10, 09:03 PM
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Are you sure 1100 sq ft home? You basement looks bigger then my whole house.. My house 1050....The boiler looks small and I might not be sized correctly. Please measure your baseboard element only for all rooms and tell us how many feet.( total for all the house) I bet we will find the issue there. Also take a pic of the boiler plate so we can see actual ratings...




Mike
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Old 12-21-10, 10:48 PM
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Heater Element Length (Fins only): 56' 11"

House size (per survey): 46.1' x 24.1' = 1,111.01 sq feet
Discount 10" outer wall: 44.43 x 22.43 = 998.76 inner space
I've confirmed the outer wall thickness with Home Designer Suite 9.0 by measuring internal room sizes and inner wall widths. (The basement probably looks large because its a full height basement with no partitions anywhere.)

I've uploaded a couple more pics. (1) Boiler Plate, (2) Pipes along chimney (they do not touch), (3) example of piping going up to a heating element (they all look the same).

After thinking about what I observed regarding how fast the temperature went up from 66 to 69 degrees on firing the boiler after purging, and then after that slowed down to a crawl, I'm inclined to believe that something kicked in to 'regulate' the system once it reached that 69 degree mark.

The only other thing I can think of is that maybe I got a bad replacement thermostat that isn't operating correctly?
 
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Old 12-21-10, 11:56 PM
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Did you ever attempt to burp the air out through the safety valve as I suggested way back in post number five? What was the result?

I'll agree with Trooper that the LWCO probe is a significant obstruction in the supply piping but unless you have had this problem since that unit was installed I don't think that is the current problem.

Let's see some pictures of where the baseboard convectors connect to the piping in the basement.
 
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Old 12-22-10, 09:55 AM
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I actually purged the air out of the system using a hose. I didn't think burping on top of that would do much of anything?

Here's a link to PhotoBucket. Furnace pictures by phillfri - Photobucket

I added one picture where piping goes up through the floor into the heating element. Not much there to see really. Its all just plain copper 3/4 inch piping run up to one end of an element and out the other end, on to the next element, around the perimeter of the basement ceiling. No valves on the heating elements. No valves anywhere on the piping except in the immediate vicinity of the boiler.

I don't know if this problem existed before. I bought the house this spring, and haven't access to the prior owners.
 
 

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