I have a 90 yr old house with hot water rads and a peerless mc05 gas boiler (dates 1991).

The water temp hardly goes up to 130 -- this does heat the house, but the rads on the second floor and third floor finished attic barely get warm.

How do I raise the water temp so its still hot on the higher floors?

Someone said the aqua is not working right.

Someone said the boiler is too small (the ratings on it are 93k 107k and max 130k)).

Someone said change the pump speed.

Someone said slow the water down by closing the main valve (s) down a bit.

Some info:

The boiler seems to have a roaring normal flame.
Everything has been bled time and time again.
The taco pump comes on when the boiler fires and runs till the boiler shuts down.
The house is all one zone - 1st floor, 2nd floor, attic, and even old school baseboard rads in basement. The feed-pipes are enorumous cast iron 4" to 3" to 2" etc. The asbestos was removed years ago so they are not wrapped. The aqua stat is a Honey l8148e. Pressure is in the 12-15 cold -20 hot range. Upstate NY 2500 sq ft brick colonial.

Any ideas? Thanks

 

There could be many reasons stopping the water temp from climbing.

first one is of course aquastat or operating limit is stopping it, and setting it higher is all thats needed.
next it may be that the boiler is sized very close to the heat load of the building and that the rads are emitting the exact heat output of the boiler.
Or, and my thought, is that the thermostat is one the main floor and is being satisfied at 130 LWT. Simply slowing down the flow to the main floor rads a pinch may help keep the boiler on longer and get the rads on the upper levels up to temp faster.

 

Stat is on the first floor.

All the rads have one valve on them, which feel frozen. I would like to choke them back a bit but I am afraid to force the valves.

How does the aquastat work? What does it do? I tried various settings on i,t and the boiler operation/water temp didnt change at all.

PS the rads on the first floor even feel luke warm...you can even grab the main feed pipe 12 inches away from the boiler and it just feels warm (not even hot).

 

If the radiator valves are stuck fully open, try loosening the packing nut slightly and then turning the valve handle. But if you throttle the valves, you will get less heat to that radiator.

Pictures might help. What is the model number of the aquastat?

I'm thinking that the boiler is set up to keep the boiler hot even when there isn't a call for heat? The aquastat should have a temperature adjustment - turn it up to about 180 deg. 130 deg isn't high enough.

If you increase the aquastat setting, the water temp should run hotter.

 

if 130 is satisfying the thermostat then 130 is enough water temp, it's just a balance issue at that point.

 

How is your water pressure? Have the radiators been bled?

 

I think I misread the original post. I agree, although 130 deg boiler temp (unknown return temp) might lead to condensation in the flue?

What, exactly, is your problem here, if the thermostat is satisfied?

You don't say where you live, except just USA (which could be Florida or Nome, Alaska). This might not be the best time of year to check out your heating. What about last winter - did you have a problem? More info needed.

 

Not a pro here but i am good at some of these things, my furnace is oil and I have baseboard heat but I have my high temp set at 165 and the low is at 130 so with a 10 degree swing, my temp gets to @ 170 when it hits the pipes making heat no problem. I would look at the settings and kick em up if you can find the temp setting dials.

 

What are the settings on the current aquastat?

How long does the boiler fire (as in actual time flame on to flame off) during a heat call?

Do you really have 3 stories that are heated (i.e., radiators in the attic)? If so, might be the pressure is a bit low. Might try bumping it up just a pound or two (and make sure the boiler pressure relief doesn't pop).

Main thing to understand is that you have what's known as a large water-volume system. All those huge pipes and rads might hold about 100 gallons of water. (In contrast, a 2500 sf house with standard 3/4" fin-tube baseboard might have 10 gallons.) So it's all getting heated. That takes a while. There are ways to address this for better performance, but first let's hear more about settings and system behavior.

If you don't need the heat coming from the distribution piping where it runs through the basement, then insulate it. Armaflex or similar insulation comes in a lot of sizes.

 

Thank you for all of the replies - I will try and answer the questions.

Someone asked the aquastat model number, someone asked the pressure, someone asked where I live, someone asked if the rads were bled -

All that info is in the original question post, last paragraph

To mikespeed - yes same problem last year.

Toheating - yes I agree if the stat is satisfied there may be no problem. I was told though that such a low water temp may cause condensation and may not be healthy for the boiler etc. Plus, for a learning experience, I am trying to figure why 99.9% of people seem to have much higher water temps.

To xiphias - The aquastat is set at 190 - However, no matter what you set it to , by lowering it or turning it up, makes no difference....the boiler behaves the exact same, same water temp etc.

Yes, three stories. The attic originally had a an enourmous cast iron rad in it that weighed probably 500lbs. When we remodeled/finshed the whole attic we removed it and put about 16 feet of baseboard in (just adapted it to the iron pipes behind the kneewall).

The boiler fires and runs for a while during a heat call - I never timed it but it seems to run forever.

PS I just got finished wrapping the feed pipes best I could. I also installed valves on the basement base-board loop so I can shut that off or throttle it down - this was easy to do because the basement loop was 3/4 copper that someone added later. The system is drained now because I pulled a rad over the summer when remodeling the kitchen. I am filling it tomorrow and firing it up this weekend.

 

The controls are set up for a cold start. If the volume of the boiler and system is large and if the boiler isn't still warm from a prior heat call, it can take a long time for the water temperature to come up.

The control diagram is here: Powered by Google Docs

Look at 24-V Relay 1K. The relay is energized whenever the thermostat calls for heat. Relay 1K has two normally open auxiliary contacts, 1K-1 and 1K-2. 1K-1 starts the circulator pump - which will run continously as long as there is a call for heat (whether or not the boiler is hot).

Contact 1K-2 opens the gas valve and starts the burner. The burner will continue to fire as long as: A. there is a call for heat (i.e., the thermostat isn't satisfied), and B. the aquastat isn't satisfied.

Here is what is happening: when there is a heat call starting from a cold system (not still warm from a prior heat call), both the pump and the burner start...but with your large volume, 3-storey system, it can take a long time for the system to heat up while you are circulating cold water. It seems that the system is working exactly as designed.

I'm not real keen on the controls setup, as designed - and if you want the system to operate differently, the controls would need to be changed. Two possibilities: you could set it up for a warm start, with the boiler temperature maintained at the aquastat setpoint continously, even when there is no heat call. That can be accomplished by jumpering contact 1K-2.

Or, you could have the pump only run when there is both a call for heat AND the boiler temp is hot (up to the aquastat's setpoint). Then, when there is a heat call, the burner will fire (assuming the aquastat isn't already satisfied) but the pump start will be delayed. This will require an additional or a different aquastat, one with normally open 120-V auxiliary contacts, in series with 1K-1.

Unless you know how to make these changes safely, you'll need help. You must to be able to follow control logic diagrams and be able to verify that you haven't unintentionally bypassed safety interlocks.

From my study of the control schematic, is looks like the original concept was for gravity circulation (the pump is shown as optional, "if required"). OK, with gravity flow, the flow wouldn't start until the boiler was warmed up. But with a circulator and with a large system, the whole shebang will operate the way yours does - and it undoubtedly has been running that way ever since it was installed 20 years ago.

You mentioned 4" piping in the system. It's conceivable that the original system was set up for steam or for gravity flow. It seems that somebody in the past decided that a pump was needed, so gravity flow would be taking a step backwards.

With three floors on one zone, balancing the system might be difficult - but you can play around with the manual radiator valves, provided you can get them to move. Photos of your boiler and nearby piping might help us better understand your system.

 

True that... which leads me to wonder how come the boiler has lasted 20 years... (I'm not familiar with that model, I might look it up later if I get some time)

Do you see any evidence of condensation?

Ever looked at the 'junk' that gets pulled out at annual cleaning time? Did anything like this ever come out?



[edit: I ASSumed when you wrote this: "The boiler seems to have a roaring normal flame." that your boiler was oil-fired. I see now after looking at the installation manual that the MC series is GAS fired... so ignore the pictures. You better not see anything that looks remotely like this coming out of a gas fired boiler! But then, I normally wouldn't associate 'ROARing' with a gas boiler ... if your boiler is actually roaring, maybe you should have that looked at too! ... If you don't have the 'book' for your boiler, you can download a PDF here: http://www.peerless-heater.com/Deskt...hod=attachment ]

Have you ever noticed any whitish 'streaking' coming from the joints of the flue pipe?

I'm not sure if you said how long you have lived with this system?

Something Xiphias said is relevant here... high water volume system. Remember that 1 BTU is defined as the amount of heat energy that is required to raise one pound of water, 1°F.

Roughly 8 pounds of water to a gallon, you might have 800 pounds of water in your system.

To raise that amount of water from say 70 to 130 -

60° x 800 lb = 48,000 BTU

So, you've got 48K BTU running in your system, emitting heat to the home. That heat will be released slowly and evenly over a fairly long period of time. Think of it as stored energy.

Contrast a system with perhaps 10 gallons. Heating from say 70 to 180. That's 110° x 80 = 880 BTU ... that's a HUGE difference! Systems such as this must be designed to shed the heat from the water into the home fairly quickly, and come back to the boiler for more.

 

There are piping strategies that will minimize the impact of a large water volume system causing flue gas condensation.

The easiest to implement would be a BOILER BYPASS pipe and valves. Properly piped, this would allow your system to still circulate the 130° water that will heat the home, but the boiler itself will be allowed to run at a higher average temperature.

This won't address the balancing issues with the upper rads being cooler, but it should be a step toward making the boiler happier.

Do you know if there is a boiler bypass already installed?

I too would like to see some pics of the system... Image hosting, free photo sharing & video sharing at Photobucket / free account / upload there / drop link here for us to view your album.

 

The way the controls are now set up, both the burner will fire and the pump will run even if the system is stone cold (which it often will be at the start of a heat call). The easiest fix is to change the controls - delay the pump's start until the boiler is hot. The original controls are premised on gravity flow.

The pump should not run when the system is stone cold. That is the fundamental problem.

 

Thank you for all of the great replies. Pics tonight.

Yes, after research it does sound like it is set up for cold start. I can also say that the system holds an enormous amount of water. When I drained it over the summer to pull a first flor rad, it seemed to take a half hour.

I have never seen any chunks of crud as in the NJtroop pic. Then again, I have never seen the unit cleaned...

One night, my first winter here, it crapped out and I called the service sticker on it. Guy came and wacked me $350 for a thermo couple. I asked him about the low water temp and his reponse was "its zero degrees outside and the house is 67 degrees inside..... everything is fine"

PS next winter t couple quit again... $8.00 in home depot installed myself in 10 min.

I never thought about it, but I guess it could have been a gravity HW or steam...how would we tell?

I know that it used to have a HUGE boiler at one time. I can tell by the footprint left behind from where it sat (probably twice the size of the current).

Also, at one point since 1929 (when built), there must have been an oil furnace. There was an oil line and fill pipe on the house, and when I drained the system the first time (not this summer but the previous), I could have sworn the water had a very faint diesel smell to it, if thats even possible (could have been my imagination though. Anywayyyy pics later. Thanks

 

What's that formula for the water pressure again? He said his is 12-15 lbs when cold. Is that enough for the three floors?

 

Sounds like you have a mixed system.
Cast iron rads, copper finned baseboard etc.

If this is the case you had better lay out what is where.
Cause if you are combining cast iron rads with copper finned baseboard and the boiler isn't primary secondary piping or piped in such a way as to provide high temp to the low mass rads, your not gonna heat S*** with them @ 130 F.

 

Roughly, 1/2 psi per foot. Enough for two floors plus a basement. Borderline for three floors plus a basement. We don't know if the boiler is in a basement.

But, good point. The third floor may not be completely bled of air?

But the fundamental problem lies in the controls. Check it out. The original design was premised on gravity flow. The pump should not run when the system is stone cold.

 

A thermocouple should last more than a year. Check if the pilot flame is positioned correctly on the thermocouple.

But your fundamental problem is the controls. Check it out. The original design was premised on gravity flow. The pump should not run when the system is stone cold.

 

I agree, totally - but the fundamental problem is the conrol setup. Check it out. The pump should not run when the system is stone cold.

 

Possibly more likely coal, later converted to oil? Is there a Majestic coal shoot from the foundation to a former coal bunker?

But, anyway, the basic problem now is how the controls are set up - not what earlier fuels might have been used. I shouldn't have brought up that subject.

The pump should not run when the system is stone cold.

 

You keep saying the pump shouldn't run when the system is cold because it was designed as a gravity flow system. I'm certainly no expert, but I have to disagree on these points. The boiler wasn't designed for gravity flow and the entire system is not just a gravity flow system any more.

If you were to wait for the boiler to become hot (probably less than a minute) before the water started to flow, then turned the pump on, the boiler would be cold within 30 seconds. There would be no difference between doing that and having the pump run from the start. I also wonder if dumping 70 degree water into a 180 degree boiler would be good for it.

 

The house has all cast iron rads on floor 1 + 2. The basement has some kind of old baseboard in one half of it that is just basically 2 inch iron pipe with 4" steel fins on it covered in some type of steel grate/cage (theres approx 50 ft of this). At some point, why I do not know, someone plumbed this (fed and returned) with 3/4 copper - unless copper was available at that time.

The attic was half finished originally but was destroyed by a fire in the 1980s. The owner at that time never refinished it post fire. Two years ago, when I bought the house, there was a huge cast iron rad stuffed in a corner of the attic. A few feet away, two cast iron pipes stubbed out thru the floor that were capped. The spacing of those pipes exactly matched the rad (so I am assuming it was there hooked up at one time). We refinished the attic, and removed the big iron rad. We then tapped into the iron stubbs with copper and two 8 ft sections of cheap baseboard...

Anyway, this was in the middle of last winter. When we bled them/opened the valves and let water flow through the basebaords, they got luke warm, almost exactly the same temp as all of the other rads in the house, and the boilers behavior didnt change at all.. it just did its 130 as it always did So yes I guess it is a mixed system now.

 

Never noticed any white streaks, have had the house for two winters so far. Yes, boiler is gas fired. By roaring I just meant seems healthy....Thanks for all the great help so far!

 

Here are the pics.

Note, coming out of the boiler is 1 1/4 copper, to approx 2-3 inch cast, then jumps up to to 4" cast feeds and returns to the front of the house (to the right in boiler pics), feeds and returns to rear of house start at 3" (to the left in pic looking at boiler). The 4", 3" etc eventually drops to 2" over about a 35 ft long run along front and rear of house (not shown). The only reason I can see they used 4" on the fron of house is there are more rads in the front (foyer, attic feeds, etc)

The boiler is empty and shut down now cause I have the kitchen gutted and pulled the rad (installed shut off valves and capped for winter). I have to fill it and get it running ASAP.

I am in the process of wrapping the pipes (as seen in pics). They were wrapped in asbestos, but an abatement was done years ago. I am doing the wrap job as an experiment to see how things change....I couldnt find the 4" wrap at the depot or lowes though. Had to order it at a plumbing supply... Needless to say the basement has always been a comfortable temp.

I included a pic of one of the rads, which is identical, plumbing etc to all the others. Dont mind the floors.. I am rehabbing the whole place

I did the pex ...the original galvanized water pipes were another nightmare

 

Also...the rads.... they are all plumbed exactly like this, with what seem to be original valves that you cannot budge).

 

I thought it was strange the t couple crapped again. Whats the proper positioning for that?

About the coal... I have a "window" near the boiler, but my neighbor said it was actually a coal chute... (?)

 

Mike:
I am going to disagree with you 100% on the pump issue.
If fact the pump should run 100% of the time to help balance the heating in the home. The boiler should inject into this constant circulation loop and should have the proper bypass / boiler protection devices.

t56tr:
Your thermcouple issues are caused by flue gas condensation, and if you don't deal with that you will have bigger problems.

Get that expansion tank off of its side so it hangs down with the pipe connection at the top, that will be the next thing that goes.

Maybe bite the bullet and replace the cheap BB with a steel panel rad or two to get some heat up there 16' of BB at 130 degree water will not likely heat the space (thought we don't know the heat loss).

 

Toheating: Does that boiler install look cobbed, expansion tank etc (ie not right)?

If so that really pisses me off. I mean I didnt pay to have it done because I wasnt here in 1991 or whatever but I know it was done by one of the more reputable heating/cooling places that has been around for 30+ years.

The attic is two small rooms maybe 10x12 each, seperated by the stairs that come up. The ceilings are low 7ft and angled because they follow the roofline. Before it was rocked we insulated it like crazy. AT the tail of last winter before the rads were bled and turned on,it would maintain 58 -60 deg just by leaving the attic door open (rest of the house at approx 65 with stat at 65). The weather broke though and it got warm so I really never found out how it was gonna be up there. Thanks for the advice so far.

It sounds like this isnt going to be an easy fix.

 

The controls, as shown in the schematic, are premised on gravity flow. A circulator is shown as optional, "if required."

If the original poster expects the system to run differently than designed, the controls will need to be modified. Either with hot start by jumpering relay contact 1K-2, by adding an aquastat to control the pump, bypass, or some other modification.

The way the controls are set up now, the system will continue to operate the same way. The water temp will not get up to the aquastat's set point, and the upper floors will not get sufficient heat, etc.

 

Nice pix.

Since your system is now drained, this would be a good time to fix all the radiator valves. I would go ahead and replace them all with new valves - there is a union fitting between the valve and the radiator.

Otherwise, you could disassmble each valve and fix what needs to be fixed. Chances are the stem packings are shot - if you get the stem to move off its backseat, it'll probably start leaking.

Getting the valves working is a high priority - they will help you balance the system so that you can get more heat to the upper floors.

If your system was originally steam, the radiator valves might be gate valves? (That might explain why they are all stuck.) You'll want angled globe valves for hot water service.

 

Aren't we talking about a standing pilot here? The thermocouple should be very hot, continuously - so I can't visualize condensation affecting it.

 

I agree about the valves..however I shouldnt have waited till mid september. There are over 20 to do. I work alot of hours for mr career and have to do this in my spare time. Even if I just did the first floor it would take me a while, and thats praying problems dont arise or I screw somthing up. I may have to wait till next spring and do them all over the summer. Its dropping to 50's at night here already.

On a side note, out of curiosity, could I ever get a boilermate or triangle tank style indirect to work with this system (if I work out the current issues first)

 

I agree with what TOHeating posted.

 

I'm now having some doubts about my belief that the controls are the problem.

But, how do we explain the inability of the boiler to satisfy the aquastat's setpoint - only reaching 130 deg and heat not reaching upper floors. The only thing I can think of is excessive radiation and/or excessive heat loss in relation to boiler output.

This is a 90-year-old house. The boiler's DOE rating is 134,000 Btu/hr. A heat-loss calculation might be helpful.

 

You ever see what happens when condensate drops on a hot thermocouple ?

I cannot tell you exactly why they fail, but I do know that they a way more prone to fail with flue gas condensation issues.

I have see hydrotherm boilers put so much condensate on the from from a cool start that people think the boiler is cracked.

All that bad water and something has to give.

 

Try to do the first floor rads, especially the ones near the stats.

If you repipe for constant circulation this may go very far in to helping balance the house out. I would start there and a boiler bypass. Pull out the rads on the third and put in either steel panel rads or there is now finned BB that operates at considerabley lower water temp.

You can easily put an indirect on the boiler.

The boiler work is ok, just not right.
Don't feel too bad there are tons of installers up here that are very reputable that refuse to install boiler bypasses. Slant fin boiler installs are especially bad as those boilers has a low temp aquastat to control the pump. All that this does is start and stop a pump as the temp fluctuates inside the boiler. Makes for nice thermal shock.

 

Adding a boiler bypass will allow the boiler to run at a higher temperature - which will reduce the hazard of flue-gas condenstation. That's a good thing.

But, a boiler bypass won't cause more heat to go to the heat emitters, which seems to be the problem here. Actually, a bypass will cause a bit less heat to go to the heat emitters because boiler efficiency will decline a little when flue gas temps increase.

 

Uhm. I can't tell exactly what is going on with your pipe work, but answer me this: Do the supply and return pipes for the 2nd floor rads go straight into the basement to tie into the rest of the system? What about the attic, do they do the same thing?

If they do, then you can zone those floors out with separate t-stats. That will be far easier than replacing all those radiator valves and trying to balance the system. The fourth picture down seems to indicate that this may be the case. I think you could even forgo the zone valves and running wire to your upper floors to simply things for now and just put in valves that allow you to restrict flow on a zone basis.

 

Without a heat loss we're just guessing. Might be the boiler's maxed out. But then it should be running A LOT. Might be the aquastat's messed up and the boiler never does get to high limit. Might be the room thermostat is too close to a radiator and the whole system never really has a chance to get up to temp. Might be the flow is sluggish (though it shouldn't be with all that large-diameter piping). Might be there's a lot of air in the top of the system.

One or more of these, perhaps?