Under Pressure (indirect water heater fail)
Is it possible for an indirect water heater to fail so the domestic water pressure backs up into the boiler system and over pressurizes it?
I have a Buderus GB142 boiler with LT200 water tank and nothing is stopping the heating system from climbing to 30psi and blowing the relief valve.
I went so far as to shut off the water supply to the boiler (verified that it is shutting 100%), drained down the system and shut off the boiler for the night.
Woke up to the system at 30psi, the bucket under the relief valve overflowed and water all over the floor.
The only other access to street pressure is the hot water tank.
I shut off the water supply valve to the tank and the pressure stopped climbing.
Can the heat exchanger coils leak internally so that pressurized domestic water is entering the boiler system?
Thanks.
Yup
Sounds like you've got it figured out. I've seen it once before on a BF White combi cor with a steel coil. I have yet to see it happen with a stainless coil but I guess it's only a matter of time.
This post was edited by an admin on November 15, 2011 12:58 AM.
Happens in steam
boilers too, and leads to an overfill condition. In fact, it's one of the first things I think about when I see an overfill condition and there is a DHW coil in the boiler...
Jamie
Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England.
Hoffman Equipped System (all original except boiler), Weil-McClain 580, 2.75 gph Carlin, Vapourstat 0.5 -- 6.0 ounces per square inch
Buderus to Lochinvar ?
Thanks for the input, I figured it was the only possibility.
My heating guy confirmed the tank is leaking internally and Buderus will cover it 100%.
For some reason they (rep/supplier, not sure who) are offering to upgrade me to a Lochinvar as a replacement.
Never heard of them, any thoughts on this brand?
I must say I'm not happy the Buderus failed after 5 years.
I was thinking of the Stainless Superstor Ultra before this offer was brought to the table.
