Boiler Pressure release valve leak troubleshooting

[GG_Mass]

Hi,
There are multiple threads in the forum regarding this issue and I read through some of hem, could not find the answer that would apply to my case -
- My expansion tank is ~3 years and has been installed by a pro and passes the "wrench clunk" test.
- The valve in image #2 has been replaced by a pro, just two months ago.


I am told that the next step, in order to remedy the issue for the pressure hitting 30PSI when the boiler is on, and thus leaking out the PRV, would be to replace the plate heat exchanger. The plate is about 6 years old.


My question is - is this a sound advice ? I did not ask why would a faulty plate exchange cause the system to over-pressurize, when the advice was given, and it left me wondering as to "why"..

Thank you.
Image 1: plate exchanger
image 2: pressure release valve
image 3: a newly replaced valve that was done as step 1 but did not resolve the issue.

 

[Fitter30]

Height from bottom of boiler to top of the highest heat emitter? Take a few pics of the boiler , piping, ex tank and pumps. What will be needed a 0-50 lb tire gauge and a bicycle tire pump.

 

[Sponsor]

 

[GG_Mass]

Please see attached images. If measurements are required will be happy to provide. ready with tire gauge and pump.

 

[Reach4]

You say that the pressure rises to 30 psi.

I suggest turning off the supply water valve, and seeing if the pressure behaves better. The automatic fillers often leak water into your heating system.

If that does not help, then you thermal expansion tank may be too small.

Follow what Fitter30 suggests, but I suspect he would agree with my thoughts on this.

 

[GG_Mass]

Okay, so far the issue possibly being the plate heat exchanger did not come up in this thread. Which interesting to me.

I'm not stating the plumber does not know what he's doing, he's quite competent according to my judgment at least. But, I would still like to find out how would a faulty plate heat exchanger cause for over pressure in the system.

 

[Fitter30]

Don't see the tridicator gauge. Without one have no idea what the water pressure or water temp.

 

[GG_Mass]

I hope this does it:

 

[Fitter30]

Need a measurement boiler to highest heat emitter.

 

[GG_Mass]

Do you mean the length of run of the copper pipe from the boiler to the highest located heat register on the living floor ? height wise they are all on the same floor, but there are some close to the boiler and naturally some farther.

 

[Fitter30]

Do you mean the length of run of the copper pipe from the boiler to the highest located heat register on the living floor ? height wise they are all on the same floor

Size and length of pipe don't need to know. Just the water height basement floor to the highest point of the system. Air handlers in basement tallest one 7'-8' ? Have upstairs main level floor to attic12'?

 

[GG_Mass]

it's a single story house, with a basement. I'd say the basement floor to living room floor is 8 maybe 9 feet. heat registers are just about floor level on the living floor.
there is no forced air in this system, it's just a hydronic system with baseboards. Hopefully that answers the question.

 

[Fitter30]

Boiler only needs 10lbs is water height of 23.1' with boiler pumps off water temp below 100°. Air pressure in ex tank 10 lbs.Drain down boiler slowly to the 10 lbs. Valve for ex tank opposite the piping end. Water streams comes out tank is bad and has to be replaced. Adjust air pressure. Fire boiler and turn on pumps.

 

[GG_Mass]

I think I understand the general idea here, but I'm not sure about the "Drain down boiler slowly to the 10 lbs", could you expand on that please ?
I've set the pressure in the expansion tank before, I think I can try and remember how it's done. I still have a bicycle pressure gauge in that area, and I think that's from the last time I did this.

 

[Fitter30]

I think I understand the general idea here, but I'm not sure about the "Drain down boiler slowly to the 10 lbs", could you expand on that please ?
I've set the pressure in the expansion tank before, I think I can try and remember how it's done. I still have a bicycle pressure gauge in that area, and I think that's from the last time I did this.

Make up water off, crack open a drain valve just watch the gauge should drop evenly if the hand sticks gauge should be replaced.

 

[GG_Mass]

I believe I followed the procedure as you described. Attached are the files of pressure reads in tank and boiler. the system is shut off at the moment. I am not sure if I need to add pressure into the tank (bicycle pump), or simply power up the system. I'll try and wait as much as I can before powering up the system, for your input. Thank you.

 

[Fitter30]

Let the water temp to 100°( by keeping the pump running and burner off )or less adjust boiler water and air pressure to 10 lbs in ex tank and fire boiler turn on the pump.

 

[GG_Mass]

Followed the procedure as noted. For the first few hours things seemed promising: system was running while boiler pressure gauge read 20psi or less.
Came back home now and checked it: Boiler gauge reads 30psi and tank at 22psi. PRV is releasing water in drops.

 

[Fitter30]

Have the fill open?

Followed the procedure as noted. For the first few hours things seemed promising: system was running while boiler pressure gauge read 20psi or less.
Came back home now and checked it: Boiler gauge reads 30psi and tank at 22psi. PRV is releasing water in drops.

Have the fill open?

 

[GG_Mass]

Have the fill open?

the fill valve that lets water from the main into the boiler is open.

 

[Fitter30]

Leave the valve closed. Two things could be happening fill valve setting is to high or it is leaking through. When you time cool the boiler back down 100° drain boiler down to 10 lbs then turn boiler and pump on. Leave fill valve closed. Give it a day. Then on the regulator with a adjustable wrench below the lever is a nut grab it and with channellock pliers grab the round piece that holds the lever it will unscrew. Loosen the nut back the screw out just till it gets loose. Open fill valve. Watch boiler pressure for two days. Pressure rises reg valve is bad leaking through. Lets see if it passes.