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Furnace/hot water heater pressure relief valve leaking

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Wanted to check here to see if anyone had any ideas. I’m by no means a professional, and I have no idea what I am doing, but two days ago, the pressure relief valve on my furnace started dripping pretty heavily. I called my oil company and they came and replaced the valve on it, and said it looked like it had deteriorated and should be fine. I believed that to be true, but then that night I went back down to the basement and it had dripped all day and filled the bucket again. I had them come back out yesterday, and the guy who showed up yesterday said that it’s likely we have a pinhole in the coil, and the whole boiler is going to have to be replaced. He said turn off the cold water and it should stop leaking. We did that and it leaked all night again last night. I called back this morning, he told me to turn off the hot water too and it still is leaking. He then told me to turn the water off where it leads to the furnace, underneath a gold thing, and turn back on my water, but then it leaked again. He then told me to turn off everything and bleed it out, and said it’s definitely a pin hole and that the whole boiler will need to be replaced next week because they can’t just replace a coil. 

I do trust his opinion, but I also want to see if anyone else has thoughts or ideas before I have to drop 2000 on a new tank next week

Comments

  • timnotscott
    timnotscott Member Posts: 18
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    updating with pics of the system
  • leonz
    leonz Member Posts: 1,160
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    Hire a licensed plumber to look at your system!!!!!!!

    Your boilers domestic hot water coil does not appear to be connected to your homes hot water plumbing in any way.

    A boiler with a pin hole leak in the domestic hot water coil would see water coming out of the two pipes connected to the existing domestic hot water coil.
    timnotscott
  • timnotscott
    timnotscott Member Posts: 18
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    @leonz so I should call for a second opinion? I don’t really know anything about the system, can you elaborate more on the two pipes part?

    I also turned off all of the water lines as well as the other valves leading to the furnace, drained the system, and now the pressure is staying around 15 and hasn’t spiked. I’ll wait and see and update if it goes up, but you don’t think it’s me needing a whole new boiler?
  • leonz
    leonz Member Posts: 1,160
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    If you did drain the boiler you would actually have zero pressure in the steam chest.
    You need a licensed plumber to check the entire system, fix that rats nest and bring
    it up to code by adding at least one low water cut off.
    mattmia2
  • JUGHNE
    JUGHNE Member Posts: 11,077
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    IIWM, first shut off the power to the boiler & pumps.

    Note the pressure in the Boiler.

    Then isolate the Tank from the Boiler.
    1. The pump that feeds/connects the Tank has 2 valves on it, you could shut them both, with 90 degree turn of the yellow handles.

    2. The other line that feeds/connects the Tank is coming off the top riser/tee (just below the relief valve) of the Boiler and looks to have a yellow handle valve also. Shut that off.

    Those lines feed the hot Boiler water thru the the coil inside the tank, that coil then heats the 40-50 gallons of your domestic water.

    On the lower LEFT where the copper connects to the bottom of the Tank there is a hose bib, IF you have valves 1 & 2 off you can slowly open that and get a small amount of water in a small bucket. This drains the water out of the internal coil and the short lengths of copper that connect it to the boiler. Leave that hose bib oen and see if it stops dripping. After an hour if it still drips then the internal coil may have a pinhole in it. That coil must hold back your house water pressure (40-50PSI) that is on the outside of it.

    Your boiler pressure should not drop if this drips.

    The Tank has hot and cold water connections on the top that supply your hot water for the sinks etc.

    Leave any valves on the top of the Tank lines turned on.

    Leave the cold water supply to the Boiler turned off for this test.

    You will have the hot water in the tank available for use but it will eventually get cold of course.

    Now wait and see if the boiler pressure rises or changes from the 15 you have.

    You use the term "Boiler" when I think you mean "Tank".

    Your boiler is OK unless there is water on the floor under it.

    You said you shut off all valves, drained the boiler and then must have opened the boiler cold water fill valve to have the system pressure up to 15 PSI??
    That means your auto pressure fill valve is doing it's job of maintaining that 15.

    You need to return things back the way they were before turning the boiler on.
    You would not want to isolate the pump for the tank and have it run dry.

    Leonz....the "steam chest" term would not be used for a water boiler.
  • hot_rod
    hot_rod Member Posts: 22,271
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    It could be a failed expansion tank that allows pressure to rise when the boiler heats?
    You have two valves on the pipes to the HTP tank from the boiler, are those the ones you shut off overnight.
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • mattmia2
    mattmia2 Member Posts: 9,754
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    I haven't read any of the rest of this besides your original question, but do not let these people in your house again.
    GGross
  • mattmia2
    mattmia2 Member Posts: 9,754
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    Do what @JUGHNE said. from what you did so far i suspect that you will find the pressure reducing valve that feeds the boiler is leaking a little and no water leaks from the coil in the indirect water heater. the fact that they replaced the pressure relief valve without testing the coil in the indirect, the expansion tank, and the pressure reducing valve makes me think they don't know what they are doing.
    GGross
  • JUGHNE
    JUGHNE Member Posts: 11,077
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    If you do the test I mentioned and no water drips out after an hour, Your coil is probably OK.

    I think your fill valve is OK if you leave the cold water to it turned on (after the above test) and the pressure does not rise in the boiler.

    The next thing mentioned is your expansion tank, I couldn't see it in the pictures.
    It might be connected to piping, maybe blue and about the size of 2 basketballs.

    Or it could be hanging up at the ceiling as a long cylinder.

    In either case show pictures of the tank and any valves that connect it to the system.

    And if the coil drips, before I sold you a new tank, I would cut the two pipes that connect the boiler to the tank. 2"-3" above the connections.
    This is to assure that the drip is from a leaky coil and not water squeaking past the yellow handle valves from the boiler.
    GGross
  • leonz
    leonz Member Posts: 1,160
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    It is listed on the I.D. tag as a hot water/steam boiler
  • timnotscott
    timnotscott Member Posts: 18
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    Okay, so I had called another plumbing place to come in and take a look, but they never showed up. The oil place I use never showed up again either or called me with a price to fix the tank. My wife and I have just been shutting off the hot and cold water to the tank, as well as shutting the valves that go from the tank to the furnace. We’ve had no issues with leaking, we just turn them on when we need hot water, and then turn it off when it’s done. (The company we used had also turned off the furnace and forgot to turn it back on, so that was fun to figure out too). We haven’t had any issues for the past few days, but today we woke up and the pressure was at 30. I drained it, we took showers and ran the dishwasher, and it slowly started leaking again. I’ve been bleeding the system all day, and it’s pretty much just gets to 25. I noticed, however, that when I purged the system, even with all of the valves closed, I was getting water constantly dripping when the relief valve was open, but I could hear a noise. The gold valve above the Amtrol (which I found out is part of the amtrol) has a black cap that was extremely loose. When I tighten it, no water drops at all with the valve open. When I loosen it, there’s a constant drip/flow. Should I leave it closed?
  • JUGHNE
    JUGHNE Member Posts: 11,077
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    Can you post pictures of the parts you refer to?

    From a ways back so we see a bigger picture, does this include the expansion tank?
  • timnotscott
    timnotscott Member Posts: 18
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  • timnotscott
    timnotscott Member Posts: 18
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    It’s the gold thing I took a separate picture of there. It’s on the pipe above the expansion tank. The top is screwed on tight right now, but as soon as I open it, you hear air and then water starts dumping from the relief valve 
  • mattmia2
    mattmia2 Member Posts: 9,754
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    That brass can thing on the air scoop above the expansion tank is an automatic air vent. The cap should be loose and only air should come out of it. If water comes out it is bad. It isn't your pressure problem, but it is something else that needs to be fixed if water comes out.

    It looks like the further forward valve at the back right of the boiler shuts off the pressure reducing valve that fills the boiler and it is shut off.

    I forget with the length of this thread, if you turn the boiler off, does the pressure increase or only while it is heating?
  • timnotscott
    timnotscott Member Posts: 18
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    mattmia2 said:
    That brass can thing on the air scoop above the expansion tank is an automatic air vent. The cap should be loose and only air should come out of it. If water comes out it is bad. It isn't your pressure problem, but it is something else that needs to be fixed if water comes out. It looks like the further forward valve at the back right of the boiler shuts off the pressure reducing valve that fills the boiler and it is shut off. I forget with the length of this thread, if you turn the boiler off, does the pressure increase or only while it is heating?
    There isn’t water coming out of it, but when it’s open, the pressure is rising.

    The pressure did increase for several days while the boiler was turned off. We turned it back on though and the pressure had been staying down, even when using the hot water. We had just been closing the 4 valves that are shut (the two on the back right behind the boiler you saw, and the cold and hot water) and bleeding the system and all seemed fine at least until the plumber showed up until this morning when it was high. That’s why I’m convinced it’s not the coil, since all water was shut off to the system, but I don’t know what I’m talking about, so I could be the most wrong 
  • timnotscott
    timnotscott Member Posts: 18
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    mattmia2 said:
    That brass can thing on the air scoop above the expansion tank is an automatic air vent. The cap should be loose and only air should come out of it. If water comes out it is bad. It isn't your pressure problem, but it is something else that needs to be fixed if water comes out. It looks like the further forward valve at the back right of the boiler shuts off the pressure reducing valve that fills the boiler and it is shut off. I forget with the length of this thread, if you turn the boiler off, does the pressure increase or only while it is heating?
    I just looked at it again and the pressure has gone up slightly so I opened that up and water did actually come out of the vent a bit 
  • mattmia2
    mattmia2 Member Posts: 9,754
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    The pressure did increase for several days while the boiler was turned off.

    Trying to make sure it isn't the expansion tank. If it is rising when the system isn't heating then it has to be potable water leaking in.

    The 2 possibilities are:
    1. The coil in the indirect water heater is leaking.
    2. The pressure reducing valve isn't holding.

    The other wrench in the works here is we don't know if those ball valves are holding.

    @JUGHNE 's test with turning off the isolation valves on the coil to the indirect (the tappings on the side in the middle and the one near the bottom just below that are the connections for the coil) and opening the drain will tell you if the coil is leaking without needing the potable water valves to the tank to hold.

    You can test the pressure reducing valve(prv) by opening the valve at the rear right of the boiler with the drain to the coil open. If the pressure starts creeping up when you open that you know the problem is the prv.
  • JUGHNE
    JUGHNE Member Posts: 11,077
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    If the system is full up to 15 PSI or so, and then with the air vent cap loose to dispel any air, you shut off the water supply to the PRV.

    Then just use the boiler as normal to see if the pressure rises.
  • timnotscott
    timnotscott Member Posts: 18
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    mattmia2 said:
    The pressure did increase for several days while the boiler was turned off.
    Trying to make sure it isn't the expansion tank. If it is rising when the system isn't heating then it has to be potable water leaking in. The 2 possibilities are: 1. The coil in the indirect water heater is leaking. 2. The pressure reducing valve isn't holding. The other wrench in the works here is we don't know if those ball valves are holding. @JUGHNE 's test with turning off the isolation valves on the coil to the indirect (the tappings on the side in the middle and the one near the bottom just below that are the connections for the coil) and opening the drain will tell you if the coil is leaking without needing the potable water valves to the tank to hold. You can test the pressure reducing valve(prv) by opening the valve at the rear right of the boiler with the drain to the coil open. If the pressure starts creeping up when you open that you know the problem is the prv.
    I’m doing the test that @JUGHNE suggested right now. So far, it’s looking good, the pressure is below 10 like it was, and the valve I was told to open is dripping still, but much less than it was and seems to be slowing down. When you say the prv in the back right, are you referring to the other red valve on the back of the boiler?
  • mattmia2
    mattmia2 Member Posts: 9,754
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    The PRV in your case is 2 devices, it looks like it is just a little bit to the side and behind the right side of the boiler. It is a check valve with a threaded vent oh the side of it then the PRV itself is a domed casting with a lever on the top similar to this:

    https://www.supplyhouse.com/Watts-0386422-SB1156F-1-2-Bronze-High-Capacity-Feed-Water-Pressure-Regulator

    There is a ball valve with a yellow handle to shut off the supply to it, assuming that ball valve is holding.
  • timnotscott
    timnotscott Member Posts: 18
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    With @JUGHNE test, how long should this drip for?
  • mattmia2
    mattmia2 Member Posts: 9,754
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    With @JUGHNE test, how long should this drip for?

    Usually not for more than a few minutes. Certainly it should stop after half an hour to an hour. If it continues and you have the valve to the PRV shut off, does the pressure in the boiler drop after a few hours?
  • JUGHNE
    JUGHNE Member Posts: 11,077
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    I assume you speak of the drip from the pressure relief valve.
    You should get the pressure up to 12-15 and then lift the relief valve lever to flow a good shot of water, you are trying to flush the valve out, I would flush twice and on the last one let the lever snap shut.

    Then with the boiler pressure up shut off the water supply.

    The pressure drop would be more of a tell than the drip.
  • timnotscott
    timnotscott Member Posts: 18
    edited August 2023
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    JUGHNE said:
    I assume you speak of the drip from the pressure relief valve. You should get the pressure up to 12-15 and then lift the relief valve lever to flow a good shot of water, you are trying to flush the valve out, I would flush twice and on the last one let the lever snap shut. Then with the boiler pressure up shut off the water supply. The pressure drop would be more of a tell than the drip.
    Apologies, I meant from this 
  • timnotscott
    timnotscott Member Posts: 18
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    mattmia2 said:
    With @JUGHNE test, how long should this drip for?
    Usually not for more than a few minutes. Certainly it should stop after half an hour to an hour. If it continues and you have the valve to the PRV shut off, does the pressure in the boiler drop after a few hours?
    The boiler pressure was under 10 to start the test, it doesn’t go lower than it currently is
  • timnotscott
    timnotscott Member Posts: 18
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    Also just want to make sure I didn’t miss anything I should turn off for the test 
  • mattmia2
    mattmia2 Member Posts: 9,754
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    If water is coming out that drain and the boiler pressure isn't dropping then it is the coil in the indirect.

    the final test would be to turn off the domestic supply to the indirect and open a hot water faucet somewhere and verify the dribble out of the drain stops.
  • timnotscott
    timnotscott Member Posts: 18
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    mattmia2 said:
    If water is coming out that drain and the boiler pressure isn't dropping then it is the coil in the indirect. the final test would be to turn off the domestic supply to the indirect and open a hot water faucet somewhere and verify the dribble out of the drain stops.
    I just did that, I turned off the water intakes to the tank, kept everything else the same, opened up a hot faucet, and the drip stopped 
  • mattmia2
    mattmia2 Member Posts: 9,754
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    its the coil in the tank. is it a stainless htp? might want to look to see if it is still under warranty.

    look at the chlorides in your water and the specs of the tank. might need a different type of tank if it is stainless and your chlorides are high.