Issue with furnace

jasko

i tried to purge my system and unfortunately there was no pressure on the return side of the gate valve (yes i isolated the zones) come to find out my back-flow valve was stuck (took it off the system and cleaned it) now the furnace has pressure and i purged the system but another issue that i have is that the pressure gets to high, im going to guess its the pressure reducing valve (i tried tightening the nut on the valve and no change in the flow from mains to furnace) so to lower the psi i opened the gate valve to decrease the system pressure to 20 psi since it creeped up to 30 i used the ball valve before the pressure reducing valve and left it shut. my question is can that be the expansion tank causing this issue or the pressure reducing valve. it seems like the system still wants to feed water and i can hear the water go into the system.

p.s. this system is a bruderus about 8 years old
Thank you a ton!!!

jasko

i would also like to note that the expansion tank feels cold to the touch, from the red label down it is hollow (normal i assume) and from the label to the top it is filled with water. but before cleaning the back flow valve it was more hollow (so i think). should i check the psi on the expansion tank ? should the psi be 12, and also a good question can i check the psi while the expansion tank is hooked onto the system. i want to make sure i do everything correct thank you all for your support and time in reading !

HVACNUT

That brass swing check was stuck? (Your other post). I don't even know why that's there. Pretty funky piping with the cross tee's.

With the valve to the PRV off, does the pressure continue to climb toward 30 psi?

It could be the expansion tank.
It could be the PRV.
It could be the indirect.

jasko

HVACNUT said:

That brass swing check was stuck? (Your other post). I don't even know why that's there. Pretty funky piping with the cross tee's.



With the valve to the PRV off, does the pressure continue to climb toward 30 psi?



It could be the expansion tank.

It could be the PRV.

It could be the indirect.

i looked up swing check but am clueless to what that is anyways this is what i took apart and cleaned since it was stuck

But after i put it back together in the furnace it makes a drip here and there. but water flows now to the system but at a higher psi.

So adjusting the nut did absolutely nothing from what i could hear the mains was pumping up water so i used the ball valve to shut off mains to the furnace to prevent high pressure.

can i test the psi on the expansion tank at this current state?

Thanks again for the reply its really appreciated

jasko

no the pressure does not climb to 30 psi when the prv valve is closed

HVACNUT

That's a Back Flow Preventer. Yes, mineral deposits will clog it.

The expansion tank must be removed to check/adjust the air pressure in the tank.

The PRV should be set to 12 psi, as should the tank.

It could be the PRV also has some gunk in it and is bypassing.

jasko

am i able to take apart the prv and clean it out??
i adjusted the prv to see if anything made a difference but nada
Thanks HVACNUT for your input.
anyone else care to share what their ideas are on this interesting system.

Steamhead

@jasko , I think you need a pro. Where are you located?

lchmb

if your tightening the stem into the pressure reducing valve your increasing it's set pressure.. you may need to reduce pressure on the boiler, back of the set stem, then fill to desired pressure.. take the model and find the online manual for it.. read up..