Re: Pressure problem in older home radiator/furnace
Don't make the mistake of assuming the ET is "empty" by the way it "feels"---too many people have been physically injured assuming this.
Regardless of what component is causing the problem, it's not something on which you should be trying to make a diy fix.
Have you noticed what the boiler gauge is reading when the pressure RELIEF valve is opening & dumping water on the floor???
If the pressure relief valve is dumping water water on the floor & the PRV is reading only 15-20 psi & BEFORE the boiler gauge hits 30 psi, then the pressure relief valve is faulty.
Otherwise, I'm stumped. And we could be missing something that a service person coming into the house can see by actually LOOKING at the system (something we can't do over the internet).
For example, the boiler may have been originally delivered with what's known as a "tankless coil", that didn't deliver enough hot tap water, that 15 years down the road is no longer used, but is still hooked up & is now leaking---who knows.
You may have zone valves on the system that are not opening because one or two of them are bad, or partially stuck, causing the boiler pressure to rise----who knows-----we'd love to eventually know what it was that caused the problem when the enigma is solved, if you can post back.
Again, you need an on the spot service person.
Last edited by Dobbs; 11-11-2012 at 12:12 PM.