Low heat from hot water baseboard system

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Old 01-02-11, 10:24 AM
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Low heat from hot water baseboard system

Hi, I'm new to this forum, and my wife and I are homeowners for about a year now. Trying to DIY on pretty much everything and learning along the way. We have a simple 1200 sqft ranch with a walk-out basement. It's baseboard hotwater with a coil over furnace/boiler/burner (not sure what the proper term is). There is only one zone that circulates around the house, room to room. I noticed that the last 2 rooms (dining room and small office room) do not heat up as well as the other rooms in this loop.

My question is, is it possible that I have air in the system? I don't really hear any gurgling, and the copper pipes seem hot. I've been thinking of wrapping some insulation around the copper heat pipes in the basement. (Older house built @1960).

I guess I'm looking for some help on some of the valves around the unit and an explanation of how the system works, id it's self purging, etc... Also, I have temp adjustments set at 170/190, is this correct for winter/North East? Below are some pictures I just took of the unit.











 
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Old 01-02-11, 11:24 AM
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See the automatic air eliminator just to the left of the circulator pump? Is the valve cap screwed down tight? If so, loosen it or remove it - otherwise it won't work. Ditto for the one just above the expansion tank.

There is an old, rusty flo-control valve above and to the right of the expansion tank. Rap on it and see if the check valve is stuck partially shut. Or, temporarily jack open the manual lift screw on top - see if it makes a difference. Anyway, put that valve on your list of things to replace eventually.

The expansion tank seems to be hanging from a copper pipe that is bowed down due to the weight. Needs better support.

If it's just your last two rooms that seem to be low on heat - could be a series system or a monoflo system with the front end hogging the heat. By feeling the piping, see where the temp seems to drop. We need more photos showing how the supply and return are piped to the individual baseboards and any valving or monoflo tees in the supplies and returns.
 
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Old 01-02-11, 11:44 AM
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If it was an air problem you would hear it.
Maybe there is too much heating element for 3/4" pipe. Depending on the output rating I would like to see around 65' max element for 3/4" pipe.
If there is carpeting in these rooms is it too close tot he baseboard and limiting the airflow through the baseboard.
What is the aquastat settings?
 
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Old 01-02-11, 02:26 PM
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Originally Posted by Mike Speed 30 View Post
See the automatic air eliminator just to the left of the circulator pump? Is the valve cap screwed down tight? If so, loosen it or remove it - otherwise it won't work.
It was tight but I loosened it by hand, and air came out and stopped. A quick burst. Leave it loose? Will air get purged?

Originally Posted by Mike Speed 30 View Post
There is an old, rusty flo-control valve above and to the right of the expansion tank. Rap on it and see if the check valve is stuck partially shut. Or, temporarily jack open the manual lift screw on top - see if it makes a difference. Anyway, put that valve on your list of things to replace eventually.

The expansion tank seems to be hanging from a copper pipe that is bowed down due to the weight. Needs better support.

If it's just your last two rooms that seem to be low on heat - could be a series system or a monoflo system with the front end hogging the heat. By feeling the piping, see where the temp seems to drop. We need more photos showing how the supply and return are piped to the individual baseboards and any valving or monoflo tees in the supplies and returns.
I will add some better support. No change from tapping the check valve. I will get some more photos of the system but it looks to me like they go in one end of the baseboard and come out the other and that's it, no valves or tees. In a circle around the house. Thanks for the help!


Originally Posted by rbeck View Post
If it was an air problem you would hear it.
Maybe there is too much heating element for 3/4" pipe. Depending on the output rating I would like to see around 65' max element for 3/4" pipe.
If there is carpeting in these rooms is it too close tot he baseboard and limiting the airflow through the baseboard.
What is the aquastat settings?
Could be too much, can I zone this type of system to separate it? What is the aquastat exactly, is it the temp setting hi/low points on the burner? If yes, I have it at 170/190. Thanks for the help!
 
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Old 01-02-11, 02:38 PM
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What does the pressure and temp say on the gauge on front of boiler?

Even though set for 190F does the boiler reach 190F

Mike NJ
 
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Old 01-02-11, 03:33 PM
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It was tight but I loosened it by hand, and air came out and stopped. A quick burst. Leave it loose? Will air get purged?
Leave it loose or off. Air can't get eliminated if the cap is on tight. I think I saw two automatic air eliminators - what about the other one?

I will get some more photos of the system but it looks to me like they go in one end of the baseboard and come out the other and that's it, no valves or tees. In a circle around the house.
So the outlet of one baseboard becomes the supply of the next baseboard, right? That would be a series arrangement, and by the time the water gets to the end of the string, it has cooled off some.

can I zone this type of system to separate it? What is the aquastat exactly, is it the temp setting hi/low points on the burner? If yes, I have it at 170/190.
Yes, you can create two separate zones, each served by separate, series strings with separate supply and returns connected to the boiler. That should help, particularly considering rbeck's concern that 3/4" may be too small to handle your load. This will require some repiping, adding two remotely controlled zone valves, and a second thermostat (one for each zone). If you create a second zone, use the same size pipe for both zones. The aquastat controls the boiler water temperature - somewhat like a thermostat. Your setting should be OK for the time being.

Until you can make permanent changes, you'll have to split the difference with the thermostat - one area a bit too warm and the other a bit too cool.

If you intend to rezone things, best to get John Siegenthaler's Modern Hydronic Heating and study it. You can try the library - sells for around $50 - but it will save that much and more if you intend to rip into your system, DIY-style.
 
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Old 01-02-11, 04:04 PM
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sells for around $50
USED maybe... if you can find a copy... try a HUNDRED and 50...

Another possibility would be to split the one big loop into two separate, parallel loops. You would do this by running a larger pipe, 1" out to the midpoint of the loop and running that back to the boiler. Disconnect one end of the loop at the boiler and join it to the other end. Connect the new pipe to where you took off the end of the loop.

Now you have two parallel loops, each serving half the house, but no hassle with all the zone controls.

By the way, running the LOW setting at 170 poses a very real scalding hazard for domestic hot water users... domestic hot water over 120 is capable of scalding, but get hit with 170 and it's almost instant... I'm sure you've been there...

You might want to look into a THERMOSTATIC TEMPERING VALVE installation. This would limit the temp of the water to the home to 120 or so...

In the meantime, try turning the low down to 150 and the diff to 15 or 20 and see if you still have enough hot water... it's a little safer and would save you some fuel.
 
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Old 01-02-11, 05:10 PM
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Tempering Valve

Troop, it looks like there is one hiding behind the greenfield in pix 1 & 5. If it works or not is another matter.
 
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Old 01-02-11, 05:33 PM
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Yer right! I diddin see dat at all... see, yer eyes ain't that bad!

So scratch the bit about the tempering valve... make sure it's around 120-125 setting.

But DO turn the LOW setting down as low as you can and still have adequate hot water. The lower you run that, the more you will save... you do want it about 20 ABOVE the setting of the tempering valve... so 140-150 should work fine. Set the diff to 15-20 ...
 
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Old 01-02-11, 06:27 PM
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Originally Posted by NJ Trooper View Post
Yer right! I diddin see dat at all... see, yer eyes ain't that bad!

So scratch the bit about the tempering valve... make sure it's around 120-125 setting.

But DO turn the LOW setting down as low as you can and still have adequate hot water. The lower you run that, the more you will save... you do want it about 20 ABOVE the setting of the tempering valve... so 140-150 should work fine. Set the diff to 15-20 ...
So if I set the low to 150 and high point to 170 instead of what I have now 170/190, that is better, right? So I have a THERMOSTATIC TEMPERING VALVE? What's the greenfield? Is that the digital box with the temp readout? Thanks for all the help everyone!
 
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Old 01-02-11, 06:44 PM
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Originally Posted by Mike Speed 30 View Post
Ditto for the one just above the expansion tank.

There is an old, rusty flo-control valve above and to the right of the expansion tank. Rap on it and see if the check valve is stuck partially shut. Or, temporarily jack open the manual lift screw on top - see if it makes a difference.
That second cap was actually loose already. That valve though, next to the tank, I lifted the little handle and it allowed water flow for a bit until it sounded like it filled up...maybe 4 seconds?
 
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Old 01-02-11, 06:46 PM
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I think Trooper is saying leave the Hi set at 190 (for heating your baseboard) and the low to 150. The diff set to 15-20. You dont need to keep the HI and LOW within 20 degrees of each other. The Minimum is 20 degrees.

Mike NJ
 
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Old 01-02-11, 06:48 PM
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Originally Posted by lawrosa View Post
I think Trooper is saying leave the Hi set at 190 (for heating your baseboard) and the low to 150. The diff set to 15-20. You dont need to keep the HI and LOW within 20 degrees of each other. The Minimum is 20 degrees.

Mike NJ
Aha..understood..I just realized that there are separate diff settings. Will do then Hi/Lo 190/150. Thanks.
 
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Old 01-02-11, 06:52 PM
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leave the Hi set at 190 (for heating your baseboard)
Correct... I might normally recommend 180 as the HIGH setting, but since you are having trouble heating the rooms at the end of the loop, 190 is probably a better choice.

So I have a THERMOSTATIC TEMPERING VALVE?
Yes. It's that 'three pipe' device with the red cap on it, located to the right of the black box with the LED display.

What's the greenfield?
A type of wire. The 'corrugated' flexible silver colored metal casing... in the pictures that wire is 'hiding' the tempering valve.

Is that the digital box with the temp readout?
That black digital box is your AQUASTAT.
 
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Old 01-02-11, 07:01 PM
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That valve though, next to the tank, I lifted the little handle and it allowed water flow for a bit until it sounded like it filled up...maybe 4 seconds?
That's not the one he meant...

You need to be careful with that handle on the water valve. You can put too much water in the boiler and next thing you know the pressure goes too high and the relief valve will open and spew hot water and steam.

To the left of the aquastat is a gauge. That gauge has two scales on it. One is for pressure, the other for temperature.

Tell us what the pressure reading is... and at what temperature... and if the temperature gauge agrees with the digital readout.
 
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Old 01-02-11, 07:01 PM
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Thank you sooo much for the explanations, I really appreciate all the responses/help today (quick by the way)! I am definately glad I joined up here. I just adjusted my temp settings.

I also just noticed that the first valve cap I loosened (it was tight) on the automatic air eliminator next to the circulator pump, is now forming small drips of water..very slow. Is that normal? Is it relieving pressure now that I loosened it? I mentioned in an earlier post that when I loosened it, air came out.
 
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Old 01-02-11, 07:04 PM
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Originally Posted by NJ Trooper View Post
That's not the one he meant...

You need to be careful with that handle on the water valve. You can put too much water in the boiler and next thing you know the pressure goes too high and the relief valve will open and spew hot water and steam.

To the left of the aquastat is a gauge. That gauge has two scales on it. One is for pressure, the other for temperature.

Tell us what the pressure reading is... and at what temperature... and if the temperature gauge agrees with the digital readout.
That explains my last post I think.... I just ran downstairs....gauge reads 55 PSI now. The temp gauge reads 195 and agrees with the digital gauge.
 
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Old 01-02-11, 07:05 PM
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the automatic air eliminator next to the circulator pump, is now forming small drips of water..very slow. Is that normal?
Close the cap again. It isn't 'normal' per se, but very much expected. Those little valves get mineral buildup and 'crud' stuck in them and they do tend to leak. Replace it in the spring... but really, as long as the other one is working, I wouldn't worry about it.
 
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Old 01-02-11, 07:08 PM
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gauge reads 55 PSI now. The temp gauge reads 195 and agrees with the digital gauge.
Check the gauge again... if you are reading 55 PSI, your relief valve would be spewing already... it's set at 30 PSI.

There are probably TWO scales on the pressure side. One is in FEET, and the other is in PSI. Check which one you are reading... 55 FEET should equal about 24 PSI, which may be a bit on the high side.

There may be a THIRD hand on that gauge... that third hand if present is only a 'bookmark'. It can be adjusted as a 'reference' point. So if you do have that third hand, ignore it for now.

Take a close up of the gauge...
 
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Old 01-02-11, 07:20 PM
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Originally Posted by NJ Trooper View Post
Check the gauge again... if you are reading 55 PSI, your relief valve would be spewing already... it's set at 30 PSI.

There are probably TWO scales on the pressure side. One is in FEET, and the other is in PSI. Check which one you are reading... 55 FEET should equal about 24 PSI, which may be a bit on the high side.

There may be a THIRD hand on that gauge... that third hand if present is only a 'bookmark'. It can be adjusted as a 'reference' point. So if you do have that third hand, ignore it for now.

Take a close up of the gauge...
Yes, I am an amateur...lol. It's about 24 PSI!

 
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Old 01-02-11, 07:50 PM
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OK, that's not too bad really. When you operated that fill valve lever, you probably added a few PSI, but you should be fine where it's at now.

A little bit about that fill valve... aka Pressure Reducing valve, aka lots of other names... (Some not so nice!)

That valve is actually a 'regulator'. It sets the MINIMUM pressure in your system. The minimum pressure is usually 12 PSI for a one or two story home. Three story home would be a bit higher.

This minimum pressure is seen when the system is COLD, which yours will never be because it stays warm to heat your domestic hot water.

The type of hot water you have ( with a coil immersed inside the boiler ) is very inefficient. The boiler needs to be kept warm 24/7 just to make hot water for the home... EVEN IN THE SUMMER...

If you are planning on staying in this home for a while, you would do well to research INDIRECT WATER HEATER, and consider having one installed at some point. They are somewhat pricey... probably over $1000 installed, but MUCH more efficient than your 'tankless coil' setup.
 
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Old 01-02-11, 07:54 PM
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By the way, has it been mentioned to you that you should have the boiler cleaned and the burner serviced YEARLY? SOP with an oil burning appliance.
 
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Old 01-02-11, 08:22 PM
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Originally Posted by NJ Trooper View Post
OK, that's not too bad really. When you operated that fill valve lever, you probably added a few PSI, but you should be fine where it's at now.

A little bit about that fill valve... aka Pressure Reducing valve, aka lots of other names... (Some not so nice!)

That valve is actually a 'regulator'. It sets the MINIMUM pressure in your system. The minimum pressure is usually 12 PSI for a one or two story home. Three story home would be a bit higher.

This minimum pressure is seen when the system is COLD, which yours will never be because it stays warm to heat your domestic hot water.

The type of hot water you have ( with a coil immersed inside the boiler ) is very inefficient. The boiler needs to be kept warm 24/7 just to make hot water for the home... EVEN IN THE SUMMER...

If you are planning on staying in this home for a while, you would do well to research INDIRECT WATER HEATER, and consider having one installed at some point. They are somewhat pricey... probably over $1000 installed, but MUCH more efficient than your 'tankless coil' setup.
Thanks for that information!

Yes, I have thought of that, but I think we're going to wait a bit until we extend the house down the road. So far it hasn't been too bad with hot water demand. I also just insulated my attic last week to help keep the heat in. A hot water heater would be a nice addition.

Originally Posted by NJ Trooper View Post
By the way, has it been mentioned to you that you should have the boiler cleaned and the burner serviced YEARLY? SOP with an oil burning appliance.
Yes, and I need to have that done but was told every 2 years. The boiler was replaced April 2009 before we bought the house because it was under warranty with the seller. So I was figuring this coming April or so after the winter.

UPDATE: The baseboard in the room that gets colder, seems to be getting much hotter now when the circulator kicks on...but I think my issue would be solved if I zoned that room/side of the house separate because right now, my thermostat is in my livingroom which seems to hold the temp real nice. Because of that, the other room cools down before the heat kicks on again. My temp solution may be an electric freestanding portable baseboard for that room this winter.

I'm going to take temperature readings in all the rooms to compare to the living room where the thermostat is.
 
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Old 01-02-11, 08:56 PM
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My temp solution may be an electric freestanding portable baseboard for that room this winter.
I know that fans can cause drafts, but if the floorplan is open enough, a small-ish fan might circulate the heat around ... and save some $$$ on electricity...

Also, if you haven't already done this, you would be surprised how much more heat you can get out of a baseboard unit after it has been cleaned. Pop off the covers and get a brush and vacuum cleaner and vacuum out all the fins. I think rbeck mentioned earlier about wall to wall carpeting... the bottom opening of the baseboard needs to be CLEAR... air MUST flow through the unit freely.
 
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Old 01-02-11, 09:12 PM
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Originally Posted by NJ Trooper View Post
I know that fans can cause drafts, but if the floorplan is open enough, a small-ish fan might circulate the heat around ... and save some $$$ on electricity...

Also, if you haven't already done this, you would be surprised how much more heat you can get out of a baseboard unit after it has been cleaned. Pop off the covers and get a brush and vacuum cleaner and vacuum out all the fins. I think rbeck mentioned earlier about wall to wall carpeting... the bottom opening of the baseboard needs to be CLEAR... air MUST flow through the unit freely.
I will clean out the fins, we remodeled the inside of the house , no carpet, all hard wood floors. Circulating the heat out of the living room is an idea! Thanks for all the help!
 
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Old 01-03-11, 06:24 AM
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For curiosity sake, get a tape and measure the amount of installed baseboard... just the part with the fins, not the straight tube... this will tell us if there is too much element installed in the single loop.

When thinking about separating into 'zones' in the future, you probably want to think about how the zones are going to interact with each other. If there is a fair amount of air exchange between the proposed zones it might not make much sense to do it. On the other hand, there might be some advantage to zoning the bedroom areas though...

One problem you might encounter... if you make the zones TOO SMALL, you will end up having a problem with the boiler SHORT CYCLING if only one small zone calls for heat. You wouldn't want that...

What is the BTU rating of your boiler?

Last thought for now... there should be 'damper flaps' on the top of the baseboard cabinets that you can close... try experimenting with closing some of the flaps in the warmer rooms... you might have some success balancing the temps in the home. Worth a shot... don't cost nuttin!
 
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