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Boiler pressure relief valve problem

4049 Views 25 Replies 5 Participants Last post by  Bondo
I had a leaking boiler relief valve. I replaced it with the same brand valve & same pressure relief rating. However the new valve is leaking too. The only different thing I see is that the old valve is rated for 510.000 BTU Hour rating- and the new valve is rated for 550.000 BTU Hour. Can this difference cause the new valve to leak. The pressure setting on both valves is the same at 30 pounds. I hope someone can help me out on this. Can't afford the service call charge for this problem.

Thank you!
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I had a leaking boiler relief valve. I replaced it with the same brand valve & same pressure relief rating. However the new valve is leaking too. The only different thing I see is that the old valve is rated for 510.000 BTU Hour rating- and the new valve is rated for 550.000 BTU Hour. Can this difference cause the new valve to leak. The pressure setting on both valves is the same at 30 pounds. I hope someone can help me out on this. Can't afford the service call charge for this problem.

Thank you!
Ayuh,.... What is the pressure of the boiler,..??

What's the style, 'n condition of it's pressure tank,..??
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Hi Bondo
I just posted another thread about my problem. To answer your question, Im thinking it could be the expansion tank? It's a Fil_trol model 110, a small tank. Pre charged pressure is 12 psi. I just put a tire gauge on the air fill valve & it reads 25 psi. I don't know if that's good or bad. How do I check it further.

Also I just got a water pressure gauge. I was going to remove the new pressure valve & install the water pressure gauge & run the system & see how hight the pressure goes. The system right now does not have a gauge installed on it so I don't know how high the pressure is climbing.

I don't see any leaks at all. When the heat shuts off & get some blow off at the vfalve, not much & then it stops. Thanks for asking & for any help you can give me.
Sounds like bad expansion tank.Did water come out the schrader when pressure was checked?
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Hi- I'm not sure what a Schrader is? I assume that is the air fill valve on the tank. If so, no water came out.

Here is what I think I need to do.Shut off the water supply & open up a hot water faucet & let the hot water run out. Then bleed off the air pressure in the tank & when the air is out, if I get water out the air fill valve, I would have a bad tank? Is this how you check the tank. Thanks for you help on this. I'm not a plumber but I can help myself a little if I know I'm going the right way.
Hi- I'm not sure what a Schrader is? I assume that is the air fill valve on the tank. If so, no water came out.

Here is what I think I need to do.Shut off the water supply & open up a hot water faucet & let the hot water run out. Then bleed off the air pressure in the tank & when the air is out, if I get water out the air fill valve, I would have a bad tank? Is this how you check the tank. Thanks for you help on this. I'm not a plumber but I can help myself a little if I know I'm going the right way.
Ayuh,... It's a tire blow-up fittin'....

Before ya go messin' with the tank,... or plumbin' another gauge,..
Doesn't yer boiler have a tridicator gauge, with temp, 'n pressure showin' on it,..??
If it don't, it oughta...
Way better than what yer schemin'....

Ya never let the air outa the tank, it's a bladder tank, 'n is pre-charged to 12psi, the normal pressure used in most boilers...

How's the Auto-fill valve lookin', 'n actin',..??
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Bondo- There is a gauge on the front of the boiler sheetmetal. But I need to go take a look at it. I know it shows temp. but I need to see if it also shows pressure.

The fill valve appears to be in good shape. It's one of those single lever ball valve type. I see no leaks or corroison on it. It works smooth, closes and opens nice. I will go take a look at that gauge now & then post what I find here. be back in a few minutes with another post. Than you!
Bondo- I just took a look at the gauge on the front of the boiler. Right now it is showing a temperature of 150 degrees and a pressure reading of 38 psi. The relief valve is a 30 psi rating.

Bondo- what does this tell you? I can't see where the gauge is actually attached because only the face of the gauge sticks out of the sheet metal. I always thought that the gauge was reading the temp & presure of the Hot water coil. Thanks
Bondo- I just took a look at the gauge on the front of the boiler. Right now it is showing a temperature of 150 degrees and a pressure reading of 38 psi. The relief valve is a 30 psi rating.

Bondo- what does this tell you? I can't see where the gauge is actually attached because only the face of the gauge sticks out of the sheet metal. I always thought that the gauge was reading the temp & presure of the Hot water coil. Thanks
Ok,... Need a picture of yer auto-fill,... 1/4 turn ball valve ain't it,...
more likely a red bell-shaped thingy...
'n you should have a ball valve, 'tween yer domestic water, 'n the bell-shaped thingy...

The auto-fill should only allow 'bout 12 psi into the system,...
Drain some water outa the bottom of the boiler, 'n watch the gauge, drop it to 'bout 10/ 12/ 15 psi...

That gauge screws into the block/water jacket, usually above/ near the firebox...
Cold, aka; room temp, it should show room temp, 'n 12 psi...
It'll show the current temp of the boiler, 'n maybe reach up to 15 psi, or so, when at full heat...

I'm guessin' the auto-fill, ain't auto-fillin' right...
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Bondo- I don't see anything like how your describing it. OK- I will get a picture or two of what I have & get them to you. This will take me a few, but I will get it done for you. After you see what I have, then we can do the water out the boiler. I will try my best. I hope you will be here a little later from now. I'm on my way now to take pictures for you. Thanks
Bondo- Here are some photos. Hope they come in OK. They show what I have. This system is getting old. Went in new about twenty five years ago. So it could be way different today. Thanks. Got my fingers crossed on the photos. Not too good at this computer stuff.

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Bondo- Im assuming that what you mean by the Auto-Fill is that large rectangular body sitting directly above the expansion tank. If so that thing is plumbed on both ends into what looks like a one inch line on both ends. It is threaded onto the tube fittings, but the male threaded ends are sweated into place.

Attached by 1/2 inch pipe there is another much smaller rectangular valve that is threaded into the top of the expansion tank. Could that valve be at fault. I looked up a diagram of the part & it has a filter screen inside it as well as other parts that regulate water & whatever else. Don't fully understand how the parts work. Please let me know if you need more photos. I'm hopeing the problem is not that large body valve plumbed into the one inch lines. If so then I will need to call in my burner service to change it out. I don't have a tourch that will handle a one inch sweat joint & I've never had good luck with sweating lines that had moisture in them. Thanks Bondo. Will wait to hear back from you for my next move.
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Bondo- Where is Chaumont River, NY. Don't have a map right now. Sounds like western, NY. Im in the lower hudson river valley in Orange county, NY Bout 1/2 half hour from Bear Mountain & west point. Closest big area is Middletown, NY. Im only 10 minutes from the NJ border & about twenty to the Pa border. You can say we got it all down here including the Tapan Zee bridge which IS NOT ready to fall down, but it sounds good to say it so they can gouge more moeny out of us.

Maddog:thumbup:
Ayuh,... Ok, in the 3rd picture, of the tank. 'n the cast iron box, 'n there's a green handled ball valve, that's open...

Where does it come from,..??
If it's line pressure, domestic water supply, the pressure is Way to high...
Shut the valve Off, 'n bleed the drain valve on the boiler to lower the pressure to 'bout 15 psi...

Donno how it coulda ever worked Right, that way...
Im assuming that what you mean by the Auto-Fill is that large rectangular body sitting directly above the expansion tank. If so that thing is plumbed on both ends into what looks like a one inch line on both ends. It is threaded onto the tube fittings, but the male threaded ends are sweated into place.
Nope, that's just an expansion chamber to knock air outa the system, 'n the auto-bleed is the brass lookin' thing on top...
Is the rust from leakin' threads, 'n just sputter from the auto-bleeder,..??
Attached by 1/2 inch pipe there is another much smaller rectangular valve that is threaded into the top of the expansion tank. Could that valve be at fault.
I doubt it...

Gotta get a handle on the feed water,...
Where's that ball valve in pic #3 line come from...
That's where the auto-fill valve set to 12 psi oughta be...
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Bondo- Where is Chaumont River, NY. Don't have a map right now. Sounds like western, NY. Im in the lower hudson river valley in Orange county, NY Bout 1/2 half hour from Bear Mountain & west point. Closest big area is Middletown, NY. Im only 10 minutes from the NJ border & about twenty to the Pa border. You can say we got it all down here including the Tapan Zee bridge which IS NOT ready to fall down, but it sounds good to say it so they can gouge more moeny out of us.

Maddog:thumbup:
Ayuh,.... Google it,.... I can danm near throw a rock into Canaduh...:laughing:

I'm actually sittin' just outside Watertown, my 2 river houses are where the Chaumont River, turns into Chaumont Bay...
Bondo- The green handle valve in the third picture. We are on a well here.
That green handle valve is in the line that comes over from the well water system at the other end of the building about 40 feet away. There is of course a pressure tank that the well pumps into. The pressure tank there cycles between 30 & 40 pounds as I recall. The well pump kicks on at the 30 Lb. low & shuts off at the 40 lb. high. There is nothing else on that line as far as I know. It's been this way & working fine until this past weekend.

I did put a air gauge on the schrader valve of the expansion tank & it shows 25 pounds, which now I think is good because that tank should be at about the same operating pressure as the well pressure tank, I would think. You are probably correct that that green handle ball valve is not the proper fil valve. But it's what I have had for 25 years trouble free. This is a real head scratcher. The guy at the hardware store here also told me it sounds like a bad fill valve or expansion tank problem.

On that rust you see on the side of the large rectangular bodied valve, I believe to be from occasional release from the air release valve that is threaded into it on top. I looked at it closely & can't see a exterior signs of mal function. Just that line of green corrosion on the side the way you see it. Don't know what to do at this point. I will need to continue this tomorrow. I have to sign off for the evening as I have some other business to take care of. I will sleep on it. If you need more info, please ask me for it. I wish I had a way to check these parts. Maybe I should just buy a new expansion tank & that small valve thats attached to it & see what happens. After all it is 25 years old.

Watertown, NY. I had to go to watertown many years ago on business. Flew up, from Newark airport in NJ. It was mid. septemner. That night it snowed & all I had on was a shirt & no jacket with me. Froze my butt off. It was also the first time I saw cars with ten foot tall poles on the bumpers so you could see what was on the other side of the snow pile on the road. Your a better man than me. Too cold, too much snow. But the fishin must be great. Thanks!

P.S. If I drain down the water to bring the pressure down to around 12-15 pounds, then use the green handle valve to throttle in enougf refill water & allow the pressure to climb would that work. What Im saying is to open the valve just a crack & full open. Does that make any sense to you?
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Bondo- The green handle valve in the third picture. We are on a well here.
That green handle valve is in the line that comes over from the well water system at the other end of the building about 40 feet away. There is of course a pressure tank that the well pumps into. The pressure tank there cycles between 30 & 40 pounds as I recall. The well pump kicks on at the 30 Lb. low & shuts off at the 40 lb. high. There is nothing else on that line as far as I know. It's been this way & working fine until this past weekend.

I did put a air gauge on the schrader valve of the expansion tank & it shows 25 pounds, which now I think is good because that tank should be at about the same operating pressure as the well pressure tank, I would think. You are probably correct that that green handle ball valve is not the proper fil valve. But it's what I have had for 25 years trouble free. This is a real head scratcher. The guy at the hardware store here also told me it sounds like a bad fill valve or expansion tank problem.

On that rust you see on the side of the large rectangular bodied valve, I believe to be from occasional release from the air release valve that is threaded into it on top. I looked at it closely & can't see a exterior signs of mal function. Just that line of green corrosion on the side the way you see it. Don't know what to do at this point. I will need to continue this tomorrow. I have to sign off for the evening as I have some other business to take care of. I will sleep on it. If you need more info, please ask me for it. I wish I had a way to check these parts. Maybe I should just buy a new expansion tank & that small valve thats attached to it & see what happens. After all it is 25 years old.

Watertown, NY. I had to go to watertown many years ago on business. Flew up, from Newark airport in NJ. It was mid. septemner. That night it snowed & all I had on was a shirt & no jacket with me. Froze my butt off. It was also the first time I saw cars with ten foot tall poles on the bumpers so you could see what was on the other side of the snow pile on the road. Your a better man than me. Too cold, too much snow. But the fishin must be great. Thanks!

P.S. If I drain down the water to bring the pressure down to around 12-15 pounds, then use the green handle valve to throttle in enougf refill water & allow the pressure to climb would that work. What Im saying is to open the valve just a crack & full open. Does that make any sense to you?
There should be a regulator on the line feeding from your well pressure tank, limiting the pressure of the water going to your boiler. If your expansion tank is ok, then when you drain it down and lower the pressure to 15 psi, you can close that valve, it doesn't need to be open. If you find the pressure dropping after you close that valve, you have a leak somewhere.
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Fill trol tank is a combo pressure reducing valve and expansion tank.Adding or removing air to tank adjust system pressure.Ive found bad tanks by giving the sides a few taps with screw driver handle.Should sound hollow in lower part.Kinda like the old school way of finding a stud in the wall.
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HVACTECH96- Thanks. I did manage to do a search this morning on the Fill-troll tank. And yes, it is a combo system that eliminates the need for a pressure regulating fill valve. There is a rectangular valve body about 3 0r 4 inches long, mounted directly to the top of the expansion tank. I have a cut away drawing of that special combo valve. Inside it has seals, springs, filter screens, etc. After 25 years of service, I would think it's on it's way to a happier place.

I will try that little tap test you suggested to see what I hear. Based on the drawing I found this morning, and all the help member BONDO gave me last night, and now your information here, I'm ready to take the plunge & replace the expansion tank & the valve that is mounted to it. I don't see anything else that could be wrong, because all the info I have, is pointing to a system that can not regulate the pressure caused by heated water.
Thank you for you help here.
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Also suggest replacing air vent at same time.They're cheap and you'll have to drain down the unit anyway.
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