# Oil Heat Problem.  Heat won't shut off in zone!!



## BARTSFAM (Jan 21, 2012)

I hate oil heat, and try to keep it shut off 90% of the time, and rely on my pellet stove, so......

I have one zone that for the past few days, the register is always warm with the forced hot water heat.  I cranked the thermostat down to the lowest, 50 degrees, and still I can feel that the register is warm. 
When I crank the register up to the highest, the boiler kicks on, and the circulator pump starts running, like it should. 

I have two other zones, and those registers are cold.  The small circulaltor pump for this zone is not on.  The motor is not running, but the pipes are warm to hot. 
The warm water from the boiler is feeding this zone. So, I googled this problem, and alot of people seem to say that some valve is stuck open, but my question is, where is this valve?  Is it something I can fix on my own? 

The pipe leaves the boiler, and there is no valve that I can see.  Only the pump, and a faucet relief valve.

Any ideas on how to fix this?  Or, do I need a repairman?


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## maple1 (Jan 21, 2012)

Post this in the boiler room, you should get some answers. Maybe a mod will move it.

For now I'll say it might be a stuck zone valve - but some systems only have circs & no zone valves.

What kind of thermostat does it have? If electronic, try popping the batteries out. Then replace if dead. Likely not the cause but worth a shot maybe.


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## woodgeek (Jan 21, 2012)

if the registers are only warm, it could be a thermosiphon (gravity driven flow).  One of my loops did that until I turned the shutoff valve.  Is the boiler running a lot, or just turning over every hour or two?


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## daveswoodhauler (Jan 21, 2012)

The zone valve should be close to your boiler, but you are right that its odd that you have at least 2-3 zones with no visible signs....sure sounds like you have a zone valve stuck open...can you post some pics of your setup? (Do you have a finished basement...maybe the valves are behind some ceiling tile or insulation?


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## BARTSFAM (Jan 21, 2012)

To answer the previous posts....No, the boiler does not turn on anymore then usual.  The hot water is going into this zone, without the thermostat calling for it.  The pump is not on, but the pipe is warm to hot.  

I did attach some pics with crudely drawn arrows, showing the offending zone.  The pipe for this zone leaves the boiler, goes thru the pump, and then shortly into the wall/foundation.  I see no other valves.


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## BARTSFAM (Jan 21, 2012)

I may just shut that yellow valve off if I cannot figure this out, until a repairman comes.


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## semipro (Jan 21, 2012)

I think Woodgeek nailed it.  
Just shut off the valve to stop the thermosiphon flow. 
And remember to open it if heat is needed.  Maybe a note hanging on the thermostat?


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## EatenByLimestone (Jan 21, 2012)

You have a pump on each zone.  With individual pumps I don't know why they would install zone valves.   It is most likely a gravity feeding system.  Older systems were intentionally built to have water heated in the boiler and move under its own power throughout the house.  It looks like this is what is happening here, but not intentionally.  


Zone valves:

http://www.google.com/search?hl=en&...urce=og&sa=N&tab=wi&ei=aMgaT8eHNeHc0QGZiIWwCw

MAtt


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## woodgeek (Jan 21, 2012)

Probably pretty harmless in the wintertime, as the smallish amount of heat is doing some good.  Close the valve in the spring, and open in the fall to reduce standby usage.  In my case, the loop was near the thermostat which caused some weird effects.

If you end up getting it fixed by a tech, I'd love some details....although I am hoping to have my boiler scrapped this year.


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## seige101 (Jan 21, 2012)

Sounds like you need a  check valve on the system to prevent thermo siphoning. This would prevent the warm water from thermo siphoning, but when the pump kicks on it would open and the water would flow freely.


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## BARTSFAM (Jan 21, 2012)

I am going to shut the valve off, probably on Monday when it's in the 40's.  I don't want the pipes to freeze. And this is a new house, (7 years old), with a new system. 
What's funny is, two zones have the valves. I can see them. And, I know that one valve was replaced for the same problem before. But, this particular zone, I cannot find the valve in plain view.  Does anyone know why the thermo siphoning occurs??


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## willworkforwood (Jan 21, 2012)

As others have said, you have pumps and no zone valves.  It's important to know if this is really something new, or perhaps just not noticed before - no sense paying for a service call if this is something "normal".  Are you certain those pipes had always been cold before?  If it really did just start happening recently, then something has changed.  Itâ€™s possible that the offending circ broke internally, and is allowing flow.  But that doesnâ€™t happen very often - these circs typically last a very long time.  Any oil burner service done recently?  You said that circ isnâ€™t on - do you know that because all circs are off (i.e. no noise at all)?  Looks like maybe 3 heat zones and one circ for DHW?  If so, has your DHW usage increased?  It's possible the DHW could be having a TS or proximity heating effect on the HW pipe.  What does the temp and PSI on your oil burner gauge read?
EDIT
Sent before you last reply.  It's very unusual to have both pumps and zone valves - can you see a make and model on the ZV?  Having both in a system would certainly make things much more complicated, and probably the cause of some unusual things happening.


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## EatenByLimestone (Jan 21, 2012)

Gravity...  Warm water is less dense than cold water do it tends to rise.  

Matt


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## BARTSFAM (Jan 21, 2012)

The last time this happend, in a different zone, the oil man blamed this thing in the picture.  He said that this valve was stuck opened, so he replaced it.  The problem is, I cannot find this thing in the zone with the problem......


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## woodgeek (Jan 21, 2012)

I have a check valve in my loop, but my service tech said that they often fail open after a few years...and that he would want several hundred dollars to replace it, since he would have to drain and refill/purge the system.  Glarg.

I am inclined to think thermosiphons are quite common in hydronic heating systems--mine increased standby by ~1 gallon/oil per day....all summer long.


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## EatenByLimestone (Jan 21, 2012)

That is an automatic air purge valve.  It lets air out if you get any in the line.  There should be one off your boiler also.   You don't need one on every zone.   

Matt


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## EatenByLimestone (Jan 21, 2012)

I don't see how a vale that lets air out of the system could start/stop your issue.   I think he might have been yanking your chain.

Matt


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## EatenByLimestone (Jan 21, 2012)

http://www.google.com/search?q=auto...e&cd=2&sqi=2&ved=0CEMQ_AUoAQ&biw=1192&bih=494

Pics of the vent without the insulation around it.


Matt


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## BARTSFAM (Jan 22, 2012)

EatenByLimestone said:
			
		

> I don't see how a vale that lets air out of the system could start/stop your issue.   I think he might have been yanking your chain.
> 
> Matt



That's just great to know. Another reason I depend on my pellet stove for heat.....


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## bjkjoseph (Jan 22, 2012)

its called a flow control valve...there is a little ball in there..and when the circulator kicks on its enough to lift that little ball..and let the water flow by...and when the circulator clicks off...the little ball falls back into place preventing the hot from flowing to that zone....my flow control valve is also broken...and i have it on the list...man that list just keeps getting longer and longer.


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## BARTSFAM (Jan 22, 2012)

UPDATE WITH MORE BAD NEWS::

Last night I went home, and the thermostat on the front of the burner showed 70 degrees, the lowest reading. I activated a thermostat, and the boiler kicked on, and heated up.

I went to bed, woke up this morning, and there was a puddle on the floor from the overflow pipe that faces downward.  

So, to review: hot water flows to a zone that does not call for it;  boiler does not seem to come on automatically unless a thermostat makes it;  and water coming out of the downward facing pipe.   

Any ideas?


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## woodgeek (Jan 22, 2012)

Sounds like the aquastat/controller.  The running cold would be a fault in the aquastat (assuming you have a tankless coil for DHW, it should never go below 130Â°F). IF the aquastat is malfunctioning, it might be swinging too high also, which could overpressure the system and blow some water out the relief valve.  

I wouldn't run it like that....but replacing an aquastat is a quick job (I replaced mine myself once).  Maybe $200 for the new hardware, less than a hour of labor.

I think this is independent of the thermosiphon....I've found that a lot of systems if not most are not working as designed, but so long as they deliver BTUs the owners don't complain.  When you actually look under the hood, you often find a lot of bugs/features from questionable installs, partial hardware failures, etc.


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## mrfjsf (Jan 22, 2012)

BARTSFAM said:
			
		

> UPDATE WITH MORE BAD NEWS::
> 
> Last night I went home, and the thermostat on the front of the burner showed 70 degrees, the lowest reading. I activated a thermostat, and the boiler kicked on, and heated up.
> 
> ...



The pipe facing downward should be connected to the high pressure relief on top the boiler. Your relief is "reliefing" the pressure if you have water coming from that pipe. Relief valves are set at 30 psi from the factory. This is telling me you have a good bit of air in your system. Normal is about 12-15 psi. Do have a pressure guage? It should be part of the aquastat on the side of the boiler. Do you have an expansion tank? Is it a bladder tank? This will be indicated by a shrader valve and also a tag that states what the air charge is. If it is a bladder expansion tank, depress the shrader, if water comes out, your bladder is shot and you need a new expansion tank. If it is not a bladder style tank and it is an overhead tank laying on its side with a drain valve at the bottom and a sight glass on the side, check your water level. It should be no more than half full of water when the boiler is running and up to temp. If it is full, drain it to half. If this does not solve your pressure issue, I can try to guide you through pushing the air out of the rest of your system.

To address your zone heat issue. If they are using pumps for each zone instead of a central pump and zone valves, each zone must have a ball type check valve. Otherwise, there is absolutely nothing to stop water to flowing to that zone when the stat is not calling. It will siphon from the other pumps running. If you cant find a check valve for this zone, you need to have one installed, period. If you have one, it is likely stuck open. 

Here is a picture and description of the check valve you took a picture of below with the insulation on it. You should have one of these on every zone if you do not have zone valves.

http://www.pexuniverse.com/store/product/34-swt-bronze-horizontal-flo-check

EDIT: Are your pumps on the return side of the boiler?


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## willworkforwood (Jan 23, 2012)

As said earlier, this sounds like a bad aquastat or controller.  A non-condensing boiler should never drop down to 70*, and the water from the pipe is an indication of high temp/pressure, and maybe even a boil-over.  You need to get someone in to get it fixed ASAP, because this type of boiler can be damaged by abnormally low/high temp swings.  And until the repair guy arrives, you can try to manually control the boiler via the t-stat, keeping the boiler temp gauge within the 120-180 range.  It's unusual to see so many problems from new work that's only 7 years old.  It might be a good idea to bring someone (new) in to evaluate the whole system - maybe there's some underlying reason for all of these problems.


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## BARTSFAM (Jan 27, 2012)

UPDATE: Friday 01/27/2012

Almost $600 later, I am all fixed!

I am not very mechanically inclined, but I beleive this is what the heat man said. First, he said that I have a "cold start" system, and that if nothing is calling on it for heat, then the boiler is not going to kick on. 

I needed two air vents replaced.  Both were corroded.. Also the backflow preventer valve needed to be replaced.  It also looked corroded and covered with metals from my water. 

The man said that it was actually hot steam that was going to that zone, because the water pressure was zero, and the system was low on water. 

So for those three things, plus an annual cleaning, $568.15.     

Thanks to everyone for their advice.


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## heat seeker (Jan 27, 2012)

Wow!
And thanks for the feedback!


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## woodgeek (Jan 27, 2012)

All sounds sensible.  And sounds like your water is corrosive.


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## Clarkbug (Jan 28, 2012)

Bartsfam,

Something I would look into is why your system had zero water pressure...  Where did it all go?  Have you had any leaks recently?  Did the tech that worked on it last time not let it fill back up?  With a closed system, you should only need to fill the system once, and once the air is purged, you really dont need to add any more water to it.  

I also have a cold-start oil boiler, and its normal for it to get cold like that when no zones call for heat.  

Is your problem all fixed, or is that one zone still acting up?  I just wonder why if it was steam that it wouldnt impact all three zones, since I wouldnt think that it would be selective like that.


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## BARTSFAM (Jan 29, 2012)

Hi;

I believe that he said that he thought that it over heated a couple of times, and the expansion tank relief pipe did have water coming from it, so maybe that was why there was water missing.

He also had to drain and refill the pipes because he said there was a lot of air in the system. 
As for the steam going to a certain zone, he did replace one of those relief valves (vent?) that I posted previously, which he said allowed the steam to go to that particular zone.
Ever since he did what he did, everything is fine, with no heat going to that zone.

One more thing about our "cold start" systems...of course he said that this was bad way to have your boiler set, because it forms alot of condensation in your boiler, leading to more rusting and corrosion.

He wanted to sell me a new aquastat, that has an outdoor sensor so it keeps your boiler more in tune with the weather.  It costs $500, but he said there was some type of rebate for $225.


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## Clarkbug (Jan 29, 2012)

I guess if you had a bad air vent and a bad fill valve, if you were a little low on water, when your system cooled down, it could suck air in, and then when heating up spill some out.  

Im no rocket scientist, but it just seems strange that a bad vent would allow steam in one pipe, but water to stay in the other three...  Then again, if its working now, then not a problem.

Cold start systems can get condensation when they first fire, which is why it wouldnt be good to short cycle them.  But they are a low-mass system so they heat up quickly to burn off the condensation.  You just want to be sure not to cycle them at low water temps.

The outdoor air reset is a good idea, but only if your distribution system can still provide heat to your house at lower water temps.  What it does is adjusts the aquastat based on the temps outside.  On the really cold days, it goes up to 180 or 200.  Mild days it will take it down to 140 or 150.  If there is a rebate, might not be a bad idea, given the price of oil these days....  However, given the above listed issues with the valves, I would look into a water treatment system / softener for your house/boiler feed.


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## Whitepine2 (Jan 30, 2012)

seige101 said:
			
		

> Sounds like you need a  check valve on the system to prevent thermo siphoning. This would prevent the warm water from thermo siphoning, but when the pump kicks on it would open and the water would flow freely.




  +1 I just put in new oil boiler with cirt's for each zone and found that when any of the cirt's were running hot water would go to least restence and cirt. It ended up I needed to put check valves in each loop now all fine, it was a pita to cut into each loop but did the trick.


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## Don2222 (Feb 1, 2012)

seige101 said:
			
		

> Sounds like you need a  check valve on the system to prevent thermo siphoning. This would prevent the warm water from thermo siphoning, but when the pump kicks on it would open and the water would flow freely.



X2 but it should be a "Sweat Check" valve not just a check valve on the supply side of the zone to prevent the heat from convecting

See pic below of My Sweat Check valve


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## BARTSFAM (Feb 19, 2012)

Hello All Again!!

I am the original poster, and unfortuantely another problem.  The boiler didn't even last a month!!

I woke up on Saturday morning, and found a good size puddle of water underneath the boiler.  I mopped it all up, and woke up this morning and was greeted by the same thing!

This water is coming from underneath the boiler, and not the downward facing pipe.  As previously posted, less then a month ago, I spent close to $600 on all new valves, and now this

From what I can tell, the water only leaks when the boiler kicks on, and the water is cold to the touch.  

Anyone have any ideas?  It looks bad to me.


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## Clarkbug (Feb 19, 2012)

Well, if its not coming from your overflow valve, that means its not the temperature/pressure relief valve.  

I would say to stand near the boiler, then have someone kick on the thermostat for you so it runs.  Then you can see where the leak is coming from.  If it only happens when its running, it could be that one of your zones has a leak in it, and it only leaks when the circ pump runs to pressurize that joint further.  

I hope its not your boiler leaking, since that would definitely be a bad deal....  

Regardless, I think you need to look into some water treatment just to make sure you dont crud up your new valves!


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## BARTSFAM (Feb 19, 2012)

I did what you said.  

When facing the boiler, the water is leaking from underneath the left side.  The water coming out is cold, but the boiler is on.  It seemed to leak out after the boiler shut off though.  Once it was off, the pooling began from underneath that left front side.


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## Clarkbug (Feb 19, 2012)

Give this a shot...  

Turn off the makeup water connection to your boiler, then cycle it again, and see if any water then leaks out of it.  What side is your boiler expansion tank on?  Do you have a pressure gauge on your system?  Does it move alot between when the boiler is on and off?


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## 250psd (Feb 19, 2012)

Clarkbug said:
			
		

> Give this a shot...
> 
> Turn off the makeup water connection to your boiler, then cycle it again, and see if any water then leaks out of it.  What side is your boiler expansion tank on?  Do you have a pressure gauge on your system?  Does it move alot between when the boiler is on and off?



It could be coming from your backflow prevention device on your make up water.


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## BARTSFAM (Feb 19, 2012)

What is the "make up" water connection?   The main pipe that supplies the water to the boiler??


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## Clarkbug (Feb 19, 2012)

"make up" water is the connection from your domestic cold water piping in the house to the heating system.  There is usually a pressure reducing valve on it (looks sort of like a bell with a screw on the top and a lever on the side of it).


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## BARTSFAM (Feb 19, 2012)

I did what you said.  I shut off the make up water.  I then started the boiler.  It still leaked, but the water that leaked this time was very warm, to almost hot.  Before it was cold. I got nervous, and turned the make up water back on...

Also, no great jump in pressure. It strayed between 40-60.


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## Clarkbug (Feb 19, 2012)

40 to 60!

Woah Nelly!

Most boilers have the pressure relief set for 30 PSI...  

But the fact that it was leaking regardless isnt a good sign.  It might be time to call someone in to take a look at it, or if you are comfortable with it, take the sheetmetal skin off of that side and look to see if something looks awry...


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## BARTSFAM (Feb 19, 2012)

You know....I think I read the pressure gauge wrong. I was reading the bottom numbers below the line, which made them 40-60.  When I read on top of the line, it was right at 30.   Below the line has a different set of numbers.
But...regardless, I'll have to call the plumber tomorrow and see what he says.


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## Clarkbug (Feb 20, 2012)

Good luck with it, and please post back with what you find!  Sorry to not be of more help.... Just hard to do via keyboard :/


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## BARTSFAM (Feb 20, 2012)

Well....I think I dodged a bullet.

It was the boiler pressure relief valve.  I did not see it, but way in the back, on the bottom right, was this relief valve, leading to a downward facing pipe. 

That was where the cold water was coming from, I just did not see it yesterday, as it is in very tight quarters. The water was tricking out of the pipe, and then going underneath the boiler and puddling in the front.

TOTAL COST:  $337

That's about $900 in servicing on a boiler that I barely use, in one month!!


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