Hi All:
I noticed my system pressure (radiant hydronic, Garn fired) was staying near 0 all the time. Also noticed my pressure relief valve appeared to be leaking. SO I drained the system (garn is on the other side of plate HX) and replaced the pressure relief. I also checked the expansion tank (diaphram) and it only had a few pounds of pressure, so I pumped it up to 12. Filled everything and the pressure sat at 12psi. Great! SO I turned things back on and brought in some heat from the Garn and all seemed great. Fired the Garn and when temps started to rise to 155 in the primary loop, the pressure reducing valve (not the pressure relief) started leaking a lot! Shut off the heat demands and when the temp drops, the valve stops leaking. Leak coming out from the top of the valve, around the nut under the plunger to do a "fast fill".
So with the fill today I ran quite a bit of water through the pressure reducing valve into the system.
First time I have ever had a problem with this in the past 10 year of operation.....
SO, is it just time to replace this valve? Should I also replace the expansion tank? It sounds "empty" with a knock on it....and it seemed like it was doing fine given the pressure guage.
Pressure guage sits a long ways from the tank and all, but everything is the same system, so presumably the pressure is also the same.
I can only assume it is this valve that is leaking for some reason...but only at higher temp. When it is leaking, pressure guage has dropped down to zero.....as if only temp related....but that doesn't make sense to me.
The joys of self maintained/installed systems!![Smile :) :)](/talk/styles/default/xenforo/smileys/grin.gif)
I noticed my system pressure (radiant hydronic, Garn fired) was staying near 0 all the time. Also noticed my pressure relief valve appeared to be leaking. SO I drained the system (garn is on the other side of plate HX) and replaced the pressure relief. I also checked the expansion tank (diaphram) and it only had a few pounds of pressure, so I pumped it up to 12. Filled everything and the pressure sat at 12psi. Great! SO I turned things back on and brought in some heat from the Garn and all seemed great. Fired the Garn and when temps started to rise to 155 in the primary loop, the pressure reducing valve (not the pressure relief) started leaking a lot! Shut off the heat demands and when the temp drops, the valve stops leaking. Leak coming out from the top of the valve, around the nut under the plunger to do a "fast fill".
So with the fill today I ran quite a bit of water through the pressure reducing valve into the system.
First time I have ever had a problem with this in the past 10 year of operation.....
SO, is it just time to replace this valve? Should I also replace the expansion tank? It sounds "empty" with a knock on it....and it seemed like it was doing fine given the pressure guage.
Pressure guage sits a long ways from the tank and all, but everything is the same system, so presumably the pressure is also the same.
I can only assume it is this valve that is leaking for some reason...but only at higher temp. When it is leaking, pressure guage has dropped down to zero.....as if only temp related....but that doesn't make sense to me.
The joys of self maintained/installed systems!
![Smile :) :)](/talk/styles/default/xenforo/smileys/grin.gif)