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Phil, Mechanical Engineer
Category: HVAC
Satisfied Customers: 6022
Experience:  Retired HVAC/ Electrical & Boiler contractor. Industrial
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I have a weil mcclaine boilercgt5 we have checked pressure

Customer Question

i have a weil mcclaine boilercgt5 we have checked pressure tank apperas to be good excessive temp on boiler blowing pressure valve off on unit
Submitted: 1 year ago.
Category: HVAC
Expert:  Phil replied 1 year ago.


Tell me where the operating temperature control is set, and where the high limit control on the boiler is set please, we can go from there.

Customer: replied 1 year ago.
i have a hobeywell vc8710-03 controler for domestic hot water for the home from the boiler and for hot water heat for the home when we use just domestic hot water the boiler opererates fine when we use it for heat the boiler operates fine for about 10 minutes then the three way valve opens without any demand from domestic hot water and pressures sky rocket any ideas
Expert:  Phil replied 1 year ago.

Hello, there are hundreds of possible wiring configurations.... those external to the boiler that you describe are important, but not the problem right now.

The problem right now is that the two (2) thermostats *inside the boilers control panel or mounted onto the side of the boiler, are set too high, or defective... it is *only those two that will keep the boiler from over heating.

Let me know a lot about your skill sets with electricity and appliances so that I can coach you most effectively... if any of this is not in your bag of tricks, tell me which direction you are from the center of the nearest city and I will get you a short list of well rated boiler outfits in your area.

We can go from there.