Syracuse

jonathan2015

No clue on make of boiler..Old 20+..... Breaker flipped separate night of pressure relief valve opening...Thought they may be related....Aquastat set to 165ish....

jonathan2015

Harvey it just seems if exchanger clogged, chimney partially blocked etc it would happen frequent since its below zero here and its constantly running.. like i said runs great when cold, seems like warmer temps cause pressure to rise to the point of relief valve opening, but still doesnt explain last monday when it was 22 out....but once since last February of 2014 weird

JUGHNE

There should be a cabinet panel on the boiler that should come off fairly easy and expose the gas valve and maybe the name plate of boiler. Pictures of both would be good help.

Harvey Ramer

Warmer weather affects the boiler in only 3 ways I can think of.

Slightly different combustion due to oxygen levels and air density.

Slightly different drafting characteristics due to difference in air densities and weight.

Main thing is, water being pumped through the boiler at a slower rate and/or return water temps being higher, due to reduced load on the system.

Check the heat exchanger.

jonathan2015

Thanks Harvey If it happens again Ill have to TRY and find a competent person to check the heat exchanger since that is out of my knowledge. JUGNE: ill look for brand

Harvey Ramer

Can you get more pictures so we can see how the piping all ties together?

jonathan2015

Harvey Ramer

More pics please. From behind the boiler also would be nice.

You have some strange piping going on. We need to identify the exact layout and component placement.

jonathan2015

cant get behind.....small room...

Harvey Ramer

If the boiler size is any indication of the system size, your expansion tank is to small.

You probably need a #60 expansion tank.

If the above is true, it makes sense why you only see the PRV pop off during warmer weather. When it's warmer the house uses less heat and the water in the zones cools off more in between cycles. When the system starts up, the exp tank can't hold all the expanding water and the prv pops. Now you have less water in the system. When the call for heat goes away, all that water cools off again and the fill valve adds some more water to the system, repeat....

When it's colder outside all the water in the system stays warmer and closer to the same density, in order to supply heat to the house. Problem goes away.

How big is the house?

This still doesn't address the fact that you had steam and smoke alarms going off. That needs taken care of right away. I have already poked my combustion analyzer in a flue pipe of a boiler like yours and seen over 1500 ppm of CO. Dangerous stuff. That other duct coming in to the bottom of the boiler, I imagine it's make up air. Make sure it's not blocked.

jonathan2015

Not too big..1800 sq but with 2 floors and and inlaw apt...That makes sense harvey... But the tank that was replaced was same size as old one which i assumed ran fine with previous owner unless they had this problem....We have more kids and using more rooms maybe.....I will look into tank...I even think i could handle that job!

jonathan2015

The steam was from the prv when it opened to drain the hot hot water......

Zman

It may have been asked but I don't see it.
Do you have a pressure and temp gauge on the system that is functioning correctly?
The relief valve is either going off due to high temp or high pressure ( or a bad valve).
What is the pressure when the boiler is off? On but cold? What is it when the system is hot?
Does the temp cycle in a normal manner? Off at 180? On at 160-170?
You need to narrow the possibilities a bit. Is it a pressure problem or a temp problem?
Carl

jonathan2015

Gauge on it works fine. off at 180 on around 160....Not sure if pressure or temp..Obviously if 1 rises the other rises..not sure how to isolate the temp from pressure rising... But yes gauge rises high to the point of PRV to open....Thought aqua stat but nope..

Ironman

Two things come to my mind:
1. The gas valve sticking open, as already mentioned. This would definitely cause the symptom to show up as it gets warmer outside and less heat is being extracted from the boiler because fewer or no zones would be calling.
2. The #30 expansion tank. With 20 zones on your system, I can't see how it could be of sufficient size to handle the expansion of that much water when it's heated. We need the btu rating of the boiler and an approximate amount of how much baseboard you have ( lineal feet) to estimate the correct size tank needed.

In the mean time, there's a simple way that you can check to see if the expansion tank is too small: purchase another tank (at least as big, but a #60 would be better); put a coupling and a boiler drain on the new tank; make sure it has at least 12 psi air pressure at the air port; then using a washing machine house, connect it to any drain valve on the system and open the valves on both ends of the hose. The tank is now connected to the system (temporarily). If your problem ceases, then you've found the issue: your expansion tank was too small or water logged.

Ironman

I just used Amtrol's sizing tool. Based upon the btu rating of your boiler and type of radiation that you have, it calculated an Extrol #60 tank as the minimum size you need.

Your current tank is a # 30. That's half the size required. You can add another #30 in parallel or install a # 60.

jonathan2015

Thanks Ironman, that makes sense...Not a heating expert so have no clue where the gas valve is, and ex.tank converting to a 60# makes sense also. Ill try and find a contractor if it acts up again....-5 out and working good....

j a_2

Your getting lots of good advice here….about the heat…I would as well check the venting codes…Smaller over the larger…

Harvey Ramer

Here is something else that might explain the alarms going off. That boiler is supposed to have a 7" vent. It looks like it does but it also looks like the duct coming in from outside is the same size. That could be a problem.

You said it's a very small room, correct? And it has a door on it, yes? If this is true, you need a minimum of 68sqin of free area to provide combustion air for both the boiler and the water heater. If the duct is 7" in diameter it's not going to cut it. You need at least a 10" duct to provide the needed air. If you have more than 2 90's and 15' of duct, bump it up to 12". You should bring the duct into the center of the room, at the ceiling and terminate it with a downward facing elbow. The outside termination should ideally be terminated in a vertical position with a cap on the top and on the opposite wall of the prevailing winds. If you have to go on the wall with prevailing winds, it would be better to extend it above the roof line of the house.

Ironman

If you remove the front panel, you'll see the gas valve. It's the aluminum component in the gas line with wires and tubes connected to it.

The thing to look for is to see if the burners are still lit once the boiler temp gets above 190*. If they are, then the Aquastat is either set too high or bad, or the gas valve is not shutting off the gas to the burners when the aquastat breaks power to it. It will require a tech with meter to determine which is causing this if the burners remain lit. You can check the dail inside the aquastat to see where it's set at. It should be 180* max. Sometimes, techs set it higher to try and compensate for a lack of sufficient baseboard in a cold area. That, coupled with an undersized expansion tank, can cause the system pressure to go too high and pop the relief valve.

jonathan2015

Harvey not sure size of duct, but its a straight shot up through house and extends over roof... only bend is really first 10'...it is a small room but we leave door open into laundry room, boiler room door ventilated also.. Remember this house is 40 years old and i assume this boiler has been venting and running fine for previous owner over 40 years....

jonathan2015

Ironman....its set at 165ish

Ironman

jonathan2015 said:

Ironman....its set at 165ish

Watch it and see if the burners shut off around that temp.

j a_2

I can’t tell for sure from the pics but is that a common vent or not? You truly need to get some one there to get this under control….Things happen for a reason….Maybe someone will accept a call from you that is competent in both heat and venting..and be able to discuss it in more detail….Check the find a contractor adds on this site for your area..Try calling the local plumbing and gas insp. and ask if he knows a good company….Out of state guys are most likely not an option, call backs and licensing, come to mind….among others...

j a_2

Maybe you can find the most competent person in your area and have him walked thru the procedures by someone on this site...

jonathan2015

upon further review...set at 180 and burners do shut off around then

jonathan2015

J A: after 3 different "competent" contractors I turned to this site to seek help...Im seek of replacing "possible" causes to have same PRV going off in middle of night on occasion...Temp rises, as pressure rises....or other way around...frustrating..

Zman

jonathan2015 said:

Gauge on it works fine. off at 180 on around 160....Not sure if pressure or temp..Obviously if 1 rises the other rises..not sure how to isolate the temp from pressure rising... But yes gauge rises high to the point of PRV to open....Thought aqua stat but nope..

If the actual gauge is reading on at 160 off at 180 every cycle, you do not have temp problem. You can then eliminate gas valve, venting, heat exchanger, controls and a whole bunch of possibilities.

Your pressure should not rise with temperature. That is the expansion tanks job. There are a handful of things that will cause the pressure to rise. The most common is a nonfunctioning, incorrectly pressured or mis sized tank.
Try closing the fill valve to eliminate the possibility that the prv is malfunctioning.
The gauge that came with that boiler would have had a pressure gauge in the middle and a temp gauge on the outside.
You need to know exactly what the pressure is doing.

nicholas bonham-carter

Why not go to the plumbing supply house (Fergusson?), and ask any of the older faces there who would be most knowlegeable about hydronics.--NBC

jonathan2015

NBC... good idea....

j a_2

Venting may not be the issue,but it sure warrants looking at…I am in the find a cotractor site in Boston under steam, because i loved it….I recently had to turn my business over…but thats another story…If you want send me an email and i may be able to contact you and give you some live assistance…not a problem…We did all hydronic heat but keyed on steam,again because I just loved it...

Zman

Ok,
The top scale on the upper part of the gauge is psi. It is at 10 psi. Does it climb to 30? Under what conditions?

jonathan2015

It does climb, hence the prv goes off and temp high as well...that is the unknown. What conditions? No clue. Hasnt happened in a week.

Zman

Well, if the the pressure is climbing with the temp, you have an expansion issue. It should stay within a few psi. There are quite a few oddball sceneries that could also be occurring. The most likely cause is an inadequate expansion tank.
Since you live in the house and have a vested interest in this, you can contribute to the solution. Start a log of the pressures and temps during the boiler cycles. Even if you end up finding a great pro, this info will help solve the problem.

Hilly

Have you made any headway? I hate not knowing the outcome of some of these mystery cases.

jonathan2015

Hi Hilly..No headway yet.. Kinda dont want to mess with yet, cold here, since everything working fine. My first step is to replace 30# expansion to 60#. That makes most sense with numerous zones working...