Boiler turns on and burns even when room is above the call temp
#1
03-02-11, 07:36 AM
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Boiler turns on and burns even when room is above the call temp
My boiler seems to randomily turn on and burn for a few minutes often during the day. This occurs when the room temperature is above the call temperature setting. The circulator pump does not start, only the boiler lighting and burning for a few minutes.
I will come home from work and see my room is a good 4 or 5 degrees warmer than the call temp and the baseboard is warm(but not hot like when the pump is circulating), so i know its been burning. And the room temp would not have gotten low enough to call for heat, so it's not like the heat was being run and I came home after it stopped and the heat i felt was the residual.
It is a gas boiler, not at home, so i cant recall the make or model, with one zone. Recently had the aquastat replaced, also a new thermostat unit. Im thinking it might be something to do with the low or high setting on the a-stat
Any ideas would be appreciated,
Sorry I can't provide more details off the top of my head.
I will come home from work and see my room is a good 4 or 5 degrees warmer than the call temp and the baseboard is warm(but not hot like when the pump is circulating), so i know its been burning. And the room temp would not have gotten low enough to call for heat, so it's not like the heat was being run and I came home after it stopped and the heat i felt was the residual.
It is a gas boiler, not at home, so i cant recall the make or model, with one zone. Recently had the aquastat replaced, also a new thermostat unit. Im thinking it might be something to do with the low or high setting on the a-stat
Any ideas would be appreciated,
Sorry I can't provide more details off the top of my head.
Last edited by InNeedofHeat; 03-02-11 at 07:48 AM. Reason: Addition
#2
03-02-11, 09:41 AM
It sounds like your boiler is a warm start boiler. That means it maintains the boiler at a set temperture whether or not there is a heat call. The boiler model will help in this identification. If the temperture over run in your rooms is not because of solar gain during the day, there could be another issue in your system allowing ghost flow.
#3
03-02-11, 10:04 AM
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hi InNeedof –
(droop just beat me. I was going to trash what I wrote below because after I thought more about it I figured it was nonsense, but I’m thinking maybe it isn’t so crazy. So…)
I’m am not one of the experts on the forum. (I hang around here in learning mode. )
But I’m wondering if the wrong kind of Aquastat was installed. A Triple Aquastat will turn on the burner to keep the boiler in a minimum temperature range for domestic hot water. So your burner will fire when the boiler temperature falls below a certain setting on the Triple Aquastat - even when there is no call for heat from the thermostat(s).
That’s the kind of setup I have, and like you describe, the burner will fire seemingly randomly and the circulator will not run. So I think if you don’t use the boiler for domestic hot water I don’t think a Triple Aquastat should be installed, if indeed that is the case.
I certainly could be all wet. I’m sure the pro’s will know what you should do.
Good luck!
(droop just beat me. I was going to trash what I wrote below because after I thought more about it I figured it was nonsense, but I’m thinking maybe it isn’t so crazy. So…)
I’m am not one of the experts on the forum. (I hang around here in learning mode. )
But I’m wondering if the wrong kind of Aquastat was installed. A Triple Aquastat will turn on the burner to keep the boiler in a minimum temperature range for domestic hot water. So your burner will fire when the boiler temperature falls below a certain setting on the Triple Aquastat - even when there is no call for heat from the thermostat(s).
That’s the kind of setup I have, and like you describe, the burner will fire seemingly randomly and the circulator will not run. So I think if you don’t use the boiler for domestic hot water I don’t think a Triple Aquastat should be installed, if indeed that is the case.
I certainly could be all wet. I’m sure the pro’s will know what you should do.
Good luck!
#4
03-02-11, 10:22 AM
If your get your domestic hot water through a tankless coil built into your boiler, it will be setup like this. I also believe that older boilers were warm start even if they didn't have that feature. Providing information about the boiler and even the aquastat model number will give some clues as to what is going on.
#6
03-03-11, 07:10 AM
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Sorry i haven't been around to update for you guys, works been killing me. Anyhow, the boiler is a Peerless - MCB-097-WPC-ID, intermittent Ignition. I do not have the info on the aquastat but im 90% sure its a triple action, it replaced an older aquastat a few months ago. The old aquastat(which looks identical to the new one) is a honeywell - L8148E 1190, i will get the specs on the new one when I get home today. My hot water comes from a hot water tank which heats the water.
If the boiler is a warm start, or the aquastat is causing the periodic start up, is there a neccesity for it even when the room temp is above the call temp?
Im just thinking about the summer as an example, it could get to be 85 degrees in the room, with the heat set at 62, and my boiler could be firing, sounds wasteful.
If the boiler is a warm start, or the aquastat is causing the periodic start up, is there a neccesity for it even when the room temp is above the call temp?
Im just thinking about the summer as an example, it could get to be 85 degrees in the room, with the heat set at 62, and my boiler could be firing, sounds wasteful.
#7
03-03-11, 07:32 AM
The water tank you mention is sperate from the boiler? Is this a traditional hot water heater?
With a warm start boiler, it shouldn't be heating your house when it maintains temperature. The pump should be off. If it is continuing to heat your house, then you are having an isse of gravity flow (ghost flow). This happenens when warm water from the boiler rises in the pipes as the cool water falls when the pump is not running. This can be fixed. If you have no need for a warm start boiler, it can be coverted to cold start.
With a warm start boiler, it shouldn't be heating your house when it maintains temperature. The pump should be off. If it is continuing to heat your house, then you are having an isse of gravity flow (ghost flow). This happenens when warm water from the boiler rises in the pipes as the cool water falls when the pump is not running. This can be fixed. If you have no need for a warm start boiler, it can be coverted to cold start.
#8
03-03-11, 07:33 AM
The 8148 is a SINGLE aquastat, and would not have been keeping the boiler warm... why on earth someone would replace a single with a triple is beyond my ability to reason.
#9
03-03-11, 07:38 AM
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The hot water tank is seperate from the boiler, well connected by a copper pipe, but im assuming just for water supply. The hot water heater itself ignites and warms the water used in the house. The boiler does not light when the water tank does.
When the boiler lights periodically, the pump does not turn on, just the burner. The act of heating this water does leave the heat ducts a little warm, but far less than when the heat is called due to a lower room temp, or forced calling at the tstat.
If this is a gravity flow issue, how expensive would it be to fix, or to transition from warm start to cold start?
and thanks everyone, for your help, it's much appreciated.
When the boiler lights periodically, the pump does not turn on, just the burner. The act of heating this water does leave the heat ducts a little warm, but far less than when the heat is called due to a lower room temp, or forced calling at the tstat.
If this is a gravity flow issue, how expensive would it be to fix, or to transition from warm start to cold start?
and thanks everyone, for your help, it's much appreciated.
#10
03-03-11, 07:41 AM
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NJ Trooper:
I will check the make and model of the aquastat when i get home, but i am pretty sure its a triple. If It was put back to a single would that take care of this issue?
Thanks for your help, much appreciated
I will check the make and model of the aquastat when i get home, but i am pretty sure its a triple. If It was put back to a single would that take care of this issue?
Thanks for your help, much appreciated
#11
03-03-11, 07:43 AM
According to NJ Trooper (he's wicked smaht about this stuff), your aquastat was replaced with the wrong model. Double check your model number when you get home. The solution seems it will be easy enough to fix by installing the correct aquastat. If you didn't have problems with gravity flow prior to the new aquastat, then you won't need to worry about that after you get the proper one installed.
#12
03-03-11, 07:46 AM
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Im hoping that is the solution Drooplug. I am pretty sure I did not have the gravity flow issue before the new aquastat was installed. I only lived in the house for about a month and a half before the astat was replaced. But I do not recall any random firings or warm ducts during that time.
Thanks.
Thanks.
#13
03-03-11, 08:21 AM
Here's a PDF link for your boiler manual in case you don't have one for it:
http://www.peerlessboilers.com/Deskt...hod=attachment
Is your system just one zone? i.e. one thermostat, no zone valves, etc ?
If they installed the wrong aquastat, I would think that you might still have recourse to have them come back and install the correct one. I know you probably paid like $700 for that, and you paid for a proper job.
http://www.peerlessboilers.com/Deskt...hod=attachment
Is your system just one zone? i.e. one thermostat, no zone valves, etc ?
If they installed the wrong aquastat, I would think that you might still have recourse to have them come back and install the correct one. I know you probably paid like $700 for that, and you paid for a proper job.
