Boiler Temprature went above 240 F

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  #1  
Old 01-07-17, 12:03 PM
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Boiler Temprature went above 240 F

Hi,
At one of my rental apartment, heat was off for 1 1/2 year and tenant never told me that he did not turn on gas in his apartment. After turning on gas, when I started boiler and circulator pump would not turn on. I tried to fix it by opening and loosening in propeller but it did not work so I have replaced it with Home Depot Taco 007 pump. That fixed pump and started circulating pump. Heat came on for 15-20 min and temp. rose upto 240 F and safety valve in boiler opened due to too high temperature. I turned off boiler for now until I have solution.

Question is How do I fix temp. going too high and still boiler does not turn off ?. Is my Aquastat is bad ? or setting in Aquastat is not correct ?. I have not changed anything in aquastat. I do not have history of this boiler when it worked last time since I am looking at first time since i bought this apartment 1 1/2 year. What if setting in aquastat is correct but still temp going up means aquastat is bad ? or sensor which senses the temprature is bad ?

One more question: My incoming Water pressure to Boiler is 100 psi but when I look at boiler guage water pressure is only 10-12 psi. I know it is correct pressure but I am not sure what reduces the water pressure ?. I do not see any Pressure Regular on cold water line going into boiler. All I see is one check valve. Can check valve reduce water pressure ?

ps. I am going to install pressure reducing valve at main line to make it 50 psi for entire apartment. having 100 psi pressure makes me nervous.

Below is info on boiler and Aquastat:
Honeywell Aqyastat Relay: L8148E
Boiler: Burnham Holiday 5
Circulating pump: Taco 007
 
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  #2  
Old 01-07-17, 01:12 PM
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To be clear temperature does not set off the relief valve. It is pressure and only pressure on your boiler and it releases at 30 PSI. If you have 12 PSI in the boiler you have a reducer somewhere. Cannot tell if aquastat is correct without know what your settings are.

More info and pics would be helpful.
 
  #3  
Old 01-07-17, 01:47 PM
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I have some of the picture. Gas Valve, Incoming water Inlet and pressure(100psi), Expansion Tank and Circulating pump and front of Boiler.

I forgot to mention in my original post. It is single zone system in small 1 bedroom apartment.
It does not have any zone valve and controlled by only one thermostat.

Are you looking for any specific view of boiler ?

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Last edited by mamin; 01-07-17 at 02:03 PM.
  #4  
Old 01-07-17, 02:22 PM
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It looks as though you have a valve to the right of the pressure gauge with a screw on top. If I'm right that is your pressure reducing valve for the boiler. Without a better pic I can't be sure. If you have 12 PSI when cold, start your boiler and see if pressure rises to 30. It shouldn't, if it does your expansion tank either needs an air charge or is defective. If the pressure goes up tap the tank with a screw driver. One side should sound hollow and one should sound solid. If both top and bottom are solid tank is filled with water and should be changed or checked to see if you have 12 to 15 PSI air charge in the bladder.
 
  #5  
Old 01-07-17, 02:43 PM
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spott,
Thank you for your quick reply. I do have water pressure 10-12 psi at boiler and when I drained system, it was 0 psi so pressure gauge seem to work as well. Pressure Reducing Valve what you are referring seems to be Backflow preventer since it does not have any way to open to release extra water. I have never seen such valve as PSV but I could be wrong. Regarding to expansion tank, I do know how to check if it is bad. I will check tomorrow when I go there.

It is still mystery how temperature of boiler went to 240 F and did not understand why relief valve released pressure while pressure at boiler was 12 psi. Let's say I checked after boiler released pressure from relief valve, still I do not think it went above 25 psi.

One more question while you are at it.
My current boiler is old and it does not have roll out switch, limit switch or damper vent. Can i install roll out switch by diverting gas valve wire to roll out switch and returning other wire from rollout switch to gas valve ?. I have extra roll out switch at home. I am concerned about any flame at boiler and roll out switch should help to turn boiler off in such condition as it does in newer boilers.
 
  #6  
Old 01-07-17, 03:40 PM
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A pressure reducing valve DOES NOT have any means to release water or pressure. Its sole purpose is to decrease the street pressure coming in to a reduced designed boiler pressure. The gauge may move but if the gauge read 25 when the relief went off and the relief valve goes off at 30 it doesn't sound like the gauge is accurate.

A backflow preventer simply stop the boiler water from backing into the potable water for the house and has no adjusting screw or anything on it. All the workings are on the inside, not visible.

If you could get a close up of the valve I mentioned and a close up of the aquastat with the cover off that may shed some light on the situation.


Again without knowing what your aquastat is set at it is impossible to know why your boiler went that high.

As far as the rollout switch is concerned all I can say is the wiring is just a series circuit where if 1 thing trips it stops the unit from firing. That being said this is a DIY site and I really wouldn't feel comfortable advising anyone to add switches or alter the manufactures schematic wiring designed for that boiler.
 
  #7  
Old 01-07-17, 04:16 PM
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It is still mystery how temperature of boiler went to 240 F and did not understand why relief valve released pressure while pressure at boiler was 12 psi.
At 240 deg F, the saturation pressure is 10 psig.

You said the relief valve lifted when the boiler gauge was indicating 12 psi. If that is correct, then there is something wrong with the calibration of the gauge or the relief valve.
 
  #8  
Old 01-07-17, 05:10 PM
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You MAY have a "Fil-Trol" expansion tank. These connect to a special valve that acts as a pressure reducing valve. The only adjustment is by adjusting the air cushion in the expansion tank.
 
  #9  
Old 01-07-17, 05:16 PM
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That make sense. I will take a closer picture for Amrtol tank fittings and see if it is Fil-Trol. Will update all of you tomorrow. Thank you very much for expert advice from everyone.
 
  #10  
Old 01-07-17, 05:21 PM
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gilmorrie,
Why would boiler did not shutdown at 240F water temperature ?. Bad Aquastat ?
 
  #11  
Old 01-07-17, 05:26 PM
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Why would boiler did not shutdown at 240F water temperature ?. Bad Aquastat ?


Join Date:Apr 2006State:NJPosts:79
That make sense. I will take a closer picture for Amrtol tank fittings and see if it is Fil-Trol. Will update all of you tomorrow. Thank you very much for expert advice from everyone.

You MAY have a "Fil-Trol" expansion tank. These connect to a special valve that acts as a pressure reducing valve. The only adjustment is by adjusting the air cushion in the expansion tank.

It is still mystery how temperature of boiler went to 240 F and did not understand why relief valve released pressure while pressure at boiler was 12 psi. At 240 deg F, the saturation pressure is 10 psig.

You said the relief valve lifted when the boiler gauge was indicating 12 psi. If that is correct, then there is something wrong with the calibration of the gauge or the relief valve.


A pressure reducing valve DOES NOT have any means to release water or pressure. Its sole purpose is to decrease the street pressure coming in to a reduced designed boiler pressure. The gauge may move but if the gauge read 25 when the relief went off and the relief valve goes off at 30 it doesn't sound like the gauge is accurate.

A backflow preventer simply stop the boiler water from backing into the potable water for the house and has no adjusting screw or anything on it. All the workings are on the inside, not visible.

If you could get a close up of the valve I mentioned and a close up of the aquastat with the cover off that may shed some light on the situation.


Again without knowing what your aquastat is set at it is impossible to know why your boiler went that high.

As far as the rollout switch is concerned all I can say is the wiring is just a series circuit where if 1 thing trips it stops the unit from firing. That being said this is a DIY site and I really wouldn't feel comfortable advising anyone to add switches or alter the manufactures schematic wiring designed for that boiler.

spott,
Thank you for your quick reply. I do have water pressure 10-12 psi at boiler and when I drained system, it was 0 psi so pressure gauge seem to work as well. Pressure Reducing Valve what you are referring seems to be Backflow preventer since it does not have any way to open to release extra water. I have never seen such valve as PSV but I could be wrong. Regarding to expansion tank, I do know how to check if it is bad. I will check tomorrow when I go there.

It is still mystery how temperature of boiler went to 240 F and did not understand why relief valve released pressure while pressure at boiler was 12 psi. Let's say I checked after boiler released pressure from relief valve, still I do not think it went above 25 psi.

One more question while you are at it.
My current boiler is old and it does not have roll out switch, limit switch or damper vent. Can i install roll out switch by diverting gas valve wire to roll out switch and returning other wire from rollout switch to gas valve ?. I have extra roll out switch at home. I am concerned about any flame at boiler and roll out switch should help to turn boiler off in such condition as it does in newer boilers.

It looks as though you have a valve to the right of the pressure gauge with a screw on top. If I'm right that is your pressure reducing valve for the boiler. Without a better pic I can't be sure. If you have 12 PSI when cold, start your boiler and see if pressure rises to 30. It shouldn't, if it does your expansion tank either needs an air charge or is defective. If the pressure goes up tap the tank with a screw driver. One side should sound hollow and one should sound solid. If both top and bottom are solid tank is filled with water and should be changed or checked to see if you have 12 to 15 PSI air charge in the bladder.

I have some of the picture. Gas Valve, Incoming water Inlet and pressure(100psi), Expansion Tank and Circulating pump and front of Boiler.

I forgot to mention in my original post. It is single zone system in small 1 bedroom apartment.
It does not have any zone valve and controlled by only one thermostat.

Are you looking for any specific view of boiler ?

Name: FrontOfBoiler.jpg Views: 19 Size: 16.2 KBName: GasValve.jpg Views: 19 Size: 16.0 KBName: NewCirculatingPump.jpg Views: 19 Size: 15.1 KBName: ColdWaterInletPressure.jpg Views: 19 Size: 17.2 KB

Last edited by mamin; Today at 04:03 PM.

To be clear temperature does not set off the relief valve. It is pressure and only pressure on your boiler and it releases at 30 PSI. If you have 12 PSI in the boiler you have a reducer somewhere. Cannot tell if aquastat is correct without know what your settings are.

More info and pics would be helpful.


Boiler Temprature went above 240 F



Hi,
At one of my rental apartment, heat was off for 1 1/2 year and tenant never told me that he did not turn on gas in his apartment. After turning on gas, when I started boiler and circulator pump would not turn on. I tried to fix it by opening and loosening in propeller but it did not work so I have replaced it with Home Depot Taco 007 pump. That fixed pump and started circulating pump. Heat came on for 15-20 min and temp. rose upto 240 F and safety valve in boiler opened due to too high temperature. I turned off boiler for now until I have solution.

Question is How do I fix temp. going too high and still boiler does not turn off ?. Is my Aquastat is bad ? or setting in Aquastat is not correct ?. I have not changed anything in aquastat. I do not have history of this boiler when it worked last time since I am looking at first time since i bought this apartment 1 1/2 year. What if setting in aquastat is correct but still temp going up means aquastat is bad ? or sensor which senses the temprature is bad ?

One more question: My incoming Water pressure to Boiler is 100 psi but when I look at boiler guage water pressure is only 10-12 psi. I know it is correct pressure but I am not sure what reduces the water pressure ?. I do not see any Pressure Regular on cold water line going into boiler. All I see is one check valve. Can check valve reduce water pressure ?

ps. I am going to install pressure reducing valve at main line to make it 50 psi for entire apartment. having 100 psi pressure makes me nervous.

Below is info on boiler and Aquastat:
Honeywell Aqyastat Relay: L8148E
Boiler: Burnham Holiday 5
Circulating pump: Taco 007

Why would boiler did not shutdown at 240F water temperature ?. Bad Aquastat ?
Or bad boiler gauge. Or aquastat not properly set.
Why would boiler did not shutdown at 240F water temperature ?. Bad Aquastat ?

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Why would boiler did not shutdown at 240F water temperature ?. Bad Aquastat ?
 

Last edited by Tolyn Ironhand; 01-08-17 at 03:37 PM. Reason: "Fixed" post format
  #12  
Old 01-08-17, 08:28 AM
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Below is from the 8148 manual and probably explains the 240 plateau. Most likely the 8148 is operating at the factory default limit setting (my bold below). But of course, it doesn’t explain the problem.

Could it be the circulator isn’t running and so the thermostat is never satisfied and thus the High Limit(240) is reached? Could that be the problem? But I guess that wouldn’t pop the Pressure Relief Valve – or would it?

Scale Range: 140F to 240F (60C to 116C) or 180F
to 240F (82C to 116C).

OPERATION AND SETTING

High Limit
The high limit switch shuts off the burner when the boiler
temperature exceeds high-limit setting. Because heating
systems differ, the correct temperature setting for one
system might not be correct for another. Follow the boiler
manufacturer recommendation for proper setting. To set,
remove cover, and turn dial until the desired setting is
directly below the pointer.

The dial stop is factory-set at the high end of the limit
scale.
To adjust, use a small screwdriver to hold the stop
away from the dial face, and turn the dial until the desired
setting is below the pointer. See Fig. 8. Release pressure
on screwdriver, and make sure the stop rests flat against
the dial face.

p.s. just looked again at post #1

I tried to fix it by opening and loosening in propeller but it did not work so I have replaced it with Home Depot Taco 007 pump. That fixed pump and started circulating pump.
Could it be that the pump really wasn't fixed?
 

Last edited by zoesdad; 01-08-17 at 08:35 AM. Reason: added p.s.
  #13  
Old 01-08-17, 09:14 AM
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Originally Posted by ZoesDad
". . . Could it be that the pump really wasn't fixed? . . .
Or it was installed without regard for the flow direction, as I learned (and posted) a few months ago !
 
  #14  
Old 01-08-17, 09:27 AM
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Great minds think alike -LOL. I was just looking at this picture and looked back over here;

*instructions on Taco 007 replacment step 9

p.s. also make sure all connections for the pump are tight - including wire-nutted connections.
 

Last edited by zoesdad; 01-08-17 at 09:32 AM. Reason: added p.s.
  #15  
Old 01-08-17, 10:13 AM
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Z,
In this case the pump working or not is irrelevant. The are 2 different circuits for the purpose of this conversation. The temp part of the aquastat is controlled by the cap tube which senses the temp of the water and turns on and off accordingly. The pump is activated when C1 & C2 is powered.

In other words even if you disconnected the pump from the circuit the boiler would still maintain a set temp and turn the boiler on & off but would deliver no heat to the house, much the same as if you had a tankless coil connected. You do not need the pump to get hot water.

Depending what the aquastat temps are set on and if the boiler will not shut off it could be way out of calibration in which case it can be tested by turning down the temp control and see if it shuts down or maybe the cap tube went bad and cannot sense temp anymore or an internal malfunction in the control itself.

Either way it most likely will need replacing but I wouldn't bother with the pump unless there's no hot water being circulated as the problem.

Just my thoughts on the situation.
 
  #16  
Old 01-08-17, 12:48 PM
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spott

I thought this was the typical sequence but I guess that is not correct:

1. thermostat calls for heat
2. 8148 sees thermostat call
3.boiler water is below high limit so 8148 closes burner relay and circulator relay
5. hot water is now being circulated through zone while burner is running
6. boiler water, as it is being heated, normally does not reach 240 High Limit because water is continually releasing heat in zone
7.zone reaches proper temperature and thermostat halts call for heat.
8. burner and circulator relays open and burner and circulator stop.

But this would be the sequence if for some reason the circulator didnt run:

1. thermostat calls for heat
2. 8148 sees thermostat call
3.boiler water is below high limit so 8148 closes burner relay and circulator relay
4. boiler hot water is NOT being circulated through zone (for some reason) while burner is running so boiler water gets hotter and hotter
5. boiler water eventually reaches 240 High Limit since boiler water is NOT continually releasing heat in zone

Thats what I thought could happen. You would never reach the 240 High Limit unless for some reason you didnt circulate the hot water and that could be because of a bad circulator relay in the 8148, or a bad circulator, or a loose connection to the circulator, or maybe the circulator in backwards. Or I guess if the thermostat circuit was stuck somehow.

I thought the circulator problem fit well to this case because mamin changed the circulator because mamin thought it was broken. I though it also could have been a bad 8148 and mamin assumed it was a bad circulator, or a mistake could have been easily made when installing the new circulator.

I dont see how the system would maintain a temperature setpoint for the boiler water with just the 8148 but maybe Im missing something. Dont you need a low limit control to do that? I thought this was a cold start system.

But Ive been wrong once or maybe twice before- LOL!!! Apparently Im not hitting the nail at all and need to be disabused of my notions as they say!!!! But live and learn.
 
  #17  
Old 01-08-17, 01:11 PM
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In my case, it was only the presence of my Taco 220 Flo-Chek that prevented the Pump from creating any flow in the wrong direction.

But that wouldn't explain the original problem . . . . boiling water and creating pressurized steam.

Would Mamin's system have risen to 240F if it were not partly empty of water ?
 
  #18  
Old 01-08-17, 01:11 PM
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joesdad,
Could it be that the pump really wasn't fixed?
No it was fixed and water was moving through baseboard. I did check baseboard and it was warming up due to hot water moving.


Also you said may be thermostat never satisfied...
Should not be the case since if temp. at boiler went above 180, it should have shut down the boiler while circulating pump running which tries to satisfy thermostat.
 
  #19  
Old 01-08-17, 01:15 PM
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@Vermont
I do not think it was installed in wrong direction but if that was installed in wrong direction will it cause issue what I have ?. Circulator pump is at return pipe and it is with down arrow means it is going in.

Why would boiler not shutdown after very high temperature ?. Or I am having two separate issue at the same time. One is high pressure and another is high temperature ?
 
  #20  
Old 01-08-17, 01:33 PM
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@joesdad

Thats what I thought could happen. You would never reach the 240 High Limit unless for some reason you didnt circulate the hot water and that could be because of a bad circulator relay in the 8148, or a bad circulator, or a loose connection to the circulator, or maybe the circulator in backwards. Or I guess if the thermostat circuit was stuck somehow.
Everything what you have explained in every steps is correct but I thought Aquastat have sensor which goes in to boiler water which continuously checks temperature of boiler water and if it reached high limit (Usually 180F), it will shut down the boiler regardless of circulator pump runs or not. There is no direct link between circulator pump and other safety feature of boiler. All Aquastat does is sends 120 V to ciculator when thermostat calls for heat. Aquastat have no way to find out if citculator pump is faulty.

Anyways, i have called my gas company to take a look at the issue since I am little worried about safety of boiler this point.
 
  #21  
Old 01-08-17, 01:39 PM
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I think we'll defer to spott on that issue; I have no experience with a boiler going over 210F . . . . which is where mine is shut down.

I guess right now, you're getting heat, and the Boiler's Burner and the Circulator will both cut out when the thermostat is satisfied, and you won't have to monitor it to prevent another PRV outburst.
 
  #22  
Old 01-08-17, 01:50 PM
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M,
You are correct in your understanding of how the control in relation to the pump operation works. Unless the aqustat is faulty the boiler should never reach 240 unless you have the limit set for that.

The boiler should shut down at the predetermined set temp no matter if the pump is working or not.

Z,
You are right about the 8148 being a cold start aqustat. The maintaining temp statement with the coil was just an example I used to show the pump did not have to run to have proper boiler operation.

Sorry for the confusion.
 
  #23  
Old 01-08-17, 03:15 PM
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mamim –
I thought Aquastat have sensor which goes in to boiler water which continuously checks temperature of boiler water and if it reached high limit (Usually 180F), it will shut down the boiler regardless of circulator pump runs or not.
What I was thinking is that your High Limit is NOT set at 180 – but is set at the factory default 240 – and so the burner would get shut down at 240 not 180.

water was moving through baseboard. I did check baseboard and it was warming up due to hot water moving.
I guess that would rule out my idea about the circulator. Maybe there were multiple problems as you guessed. If the Aquastat is bad then maybe even though it’s set for High Limit=180 it just keeps going and doesn’t shut off.

But it seems like an awful coincidence that the magic number you see is 240 – which just happens to be the factory set High Limit default. But maybe there is something else about the number 240. I don’t blame you for bringing in the gas company.

You should be able to look at the 8148 and see what the High Limit is set at.

If you look at figure 8 on page 7 of this manual you can see a pointer depicted on the control. Supposedly you should be able to look at the number on the dial under that pointer and see what the High Limit is set at. But if you do want to look you have to be very careful NOT TO GET A SHOCK. Better to turn all power off before you take off the cover if you do decide to look.


http://s3.supplyhouse.com/manuals/13..._PROD_FILE.pdf


(forgot to say if it is set at 180 then I guess there has to be something wrong with the 8148 aquastat- it is not shutting down when it should)
 
  #24  
Old 01-08-17, 03:40 PM
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@zoesdad, spott, vermont, glimorrie
Thank you very much for great input. You guys are fantastic.

I will wait for my gas company to fix the issue. I am able to fix so many issue in different boiler but I believe it is better if someone professional looks at this issue. I would never want to see highest possible temp. in my boiler since if it goes above that there is no temp. gauge to tell me it is above 240 which can blow up everything. When I am at my rental next time, I will definitely look at what is it set to and most likely it is at 240 which i would change it to 180 instead.
 
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