Welcome! Here are the website rules, as well as some tips for using this forum.
If you've found help here, check back in to let us know how everything worked out.
It's a great way to thank those who helped you.
LAARS Mighty Therm 2 Help...
My company took over a contract for a medium sized condo, they have 3 LAARS Mighty Therms for Heat, and 1 Mighty Therm 2 / Storage Tank for DHW.
I walked in first day today for PM on all 4 boilers and found the floor of the mechanical room covered in water, the Pressure Relief Valve on the DHW boiler is lightly but consistently going off as boiler temps rise.
Expansion tank is a 4.5 gallon Watts, I put a pressure gauge on the air side of tank and got 80psi.
The pressure gauge on the heat exchanger manifold pins out just before the relief goes off, the pressures are getting way to high during expansion. Even when the DHW 120* is satisfied the pressures are still abnormally high, just not high enough to pop the relief valve.
I have narrowed things down to either the Expansion tank is under sized, or the Pressure Reducing Valve is giving out and letting Boston Ma utility pressure in un-regulated.
I haven’t been able to track down the PRV yet due to recent renovations done on the building, also worth noting is the Pressure Relief Valve is rated for 125psi.
Any opinions on what might be causing this high pressure/pressure relief valve leak would be greatly appreciated.