View Full Version : Boiler not working on coldest day of the year

01-03-2010, 08:06 AM
17 degrees outside is cold in these parts. The indoor temp was 49 degrees when we woke up.

No apparent problems with thermostat (Honeywell Chronotherm IV). Still I removed it and twisted the R & W wires together. The boiler started up briefly. When it stopped I went down to check & found the relay buzzing. I'm assuming that it needs to be replaced and that I will not have heat until it is.

I would appreciate any information which would confirm my conclusion or not. If there is any way to get the system working today, I'd love to hear about it. I assume that it would be hard to obtain a new relay on a Sunday. Plus I am unsure that I should tackle this as a DIY project.

My fallback is to call our HVAC company. I assume he's got someone on call for emergencies such as this.

Any advice appreciated.

Good Sunday service from our HVAC company. The impeller in the pump is bad, so the pump wasn't working. The water temp sensor shut down the boiler. The pump was disassembled and the impeller freed up & lubricated. System was started. Pump stumbled, but finally began working. House is slowly heating up. Will be scheduling rebuld of impeller part of pump tomorrow. It is a cold & windy night. We are thankful to have the heat back on.

01-03-2010, 08:27 AM
Call the HVAC guy now. If your pipes freeze, it will the most expensive call you did not make.

Best of luck

01-03-2010, 11:52 AM
There are so many things that it could be...you gave us very little to go on. The brand of thermostat is irrelevant.

The water pressure could be low because of a leak, the flame sensor could be shot, if it is closed-combustion, the air intake could be clogged with snow, a squirrel, ice, etc., the circulator could be shot, and numerous other possibilities.

A buzzing relay might not be a problem - it could be that the load it is controlling is excessive or the controller that is trying to energize it lost a diode. All sorts of things. If you were lucky, you might find a compatible relay at a big box store, but I wouldn't count on anyone there being of much help. You'd have to know what might work.

A little more info, and there's a possibility someone could help, but if you don't have the manual and any diagnostic tools, it might be very hard to do anything.

01-03-2010, 01:27 PM
If there's any air or moisture exchange between the heated and unheated areas, you will have problems...you probably have a vapor barrier between the house and outside, but likely don't between the heated and unheated areas of the house. SO, any moisture that does migrate into that space at 25 degrees, will freeze if it condenses.