I have a gas fired Utica Boiler and the Pressure Relief Valve started leaking this week.

Some facts - one story house, eight cast iron radiators, boiler replaced within past 15 years, expansion tank is mounted to basement ceiling above boiler. Over summer I drained the system to remove a radiator, put back, tested system and did not have propper circulation. Drained system again and replaced circulator pump and now circulation is fine but leaking pressure release valve fills up a 5 gallon pal about every 10 hours. Automatic water intake shuts off at 12 psi. When system is running PSI fluctuates b/t 12 & 20 psi and not sure if this is a new thing or it's supposed to flucutate when operating.

As a test, I shut off water intake and opened pressure release valve to reduce psi to zero to see if leak would stop, and it did stop. When I opened the intake and it filled back up to 12 psi, it started leaking again. Rate of leak is about steady whether system is on or off.

What I'm trying to figure out is whether it's just a faulty valve that needs replacing or could it be something more serious. If just a valve any tips on how to replace, like do I have to drain system again or just shut off water intake?

Any help would be much appreciated.

Ed M.

 

If the relief valve is leaking with 12 PSI on it, and you are pretty sure the gauge is reasonably accurate, then that relief valve is defective. Sometimes during system maintenance 'crud' gets broken loose and can lodge in the valve preventing it from closing properly.

I would replace it if I were you. Yes, you will need to drain the system, at least far enough that you don't get water all over the place. You may have some valves that you can close in order to isolate parts of the system so that you may not need to entirely drain. The less you drain the better. Fresh water is not friendly to a boiler.

When you say the pressure 'fluctuates' what exactly do you mean ? Is it 12 PSI when cold, then slowly increases to 20 PSI when hot ? _or_ Does the needle bounce around wildly when running ?

If the former, some pressure increase is normal when heating water, because the water is going to expand in the system. The amount of increase you see is dependent on your expansion tank size and type, and if that tank is waterlogged, or the pressure on the tank is correctly set.

If the latter... I dunno ... which is it ?

 

PSI is at 12 when cold and slowly increases when operating and water is heated. If this is normal then good.

I'm on my way to Home Depot to look for the replacement valve.

 

It could be your reducer valve or the expansion tank.

If the reducer is not isolated with valves yes you would have to drain the system.

If the expansion tank is filled with water it could be shot.

 

I found the replacement valve at HD, drained system, installed, and filled back up.

After a while the PSI did go over 30 and the new valve did it's job by draining and releasing the pressure. I let furnace finish it's cycle and after it kicked off the new valve is not dripping or anything so it definitely needed replacing. Glad that's done.

Now need to figure out why PSI is getting too high. Expansion tank is filled with water and was filled when it was cold this morning. Pretty sure it's automatically filling up when when I fill the system back up. There is one line to the tank with a valve and this valve has remained open throughout. There is also a valve at the other end of the tank that I can hook a hose up to if I need to drain and replace.

Any thoughts as to how to know if it bit the dust and needs to be replaced?

Thanks again, EM.

 

What type of tank is it? Does it have a hose bib for draining or a tire type valve on one end?

 

When you refilled the system, you didn't forget and leave the 'fast fill' valve open, did you ?

 

When I refilled the system I believe that the Fast Fill valve was not open. The valve is equipped with the Fast Fill thumb screw feature. As the system was refilling this thumb screw was not turned completly down but was loose so it turned freely. I think this means that it was not open?

The expansion tank has a hose bib for draining and attached to the same pipe coming from tank as the hose bib, is what looks like a bleeder valve like you see on the radiators. My bleeder valve key fit it and when I opened it water did come out.

 

I suggest you start by isolating the tank from the system & draining it COMPLETELY. It is possible you've lost some of the air cushion. Once the tank is empty, close the drain valve & open the valve to the system slowly. Try not to let the system pressure drop below about 10#.

 

The procedure to drain the expansion tank and slowly fill it worked. It has been a couple of weeks now and the system has been working great. The pressure has been in check and all rooms in the house are nice and warm. With the help I received here I was able to do it myself and save lots of $$.

Thanks.

 

Good job. Glad we were able to help. Should any other problems arise, we are here & will do what we can to help you out.

 

Thanks for the feedback! It's always nice to hear a success story. That money you saved... throw a few bucks at a charity, you'll still be ahead of the game!