"Eraserhead" wrote in message

I pulled the thermostat off the wall and tipped it all the way to one side
(old mercury type) and the boiler kicked on. So since the thermostat was
pretty old, I went and bought a new one. Wired it up and all seemed good.
The boiler was running, etc. But after all day yesterday and last night it
won't get above 60 degrees in the house. It has been very cold here the
last two days (about -4 without the wind chill).

So my question is, could this be something with the thermostat since it
seems to be steady at 60 (even though the thermostat is set at 74). Or is
there something with the boiler that I can check for?

It may not be enough capacity for the house. Is the burner turning off and
on once in a while? If it is cycling properly, the thermostat is working.
What is the aquastat set at? If it is too low, the water will not get hot
enough to carry the heat needed. Find out what the recommended setting is
and use that. You don't want to make steam, just have the water hot enough
to be efficient.

The thermostat usually turns on the circulator pump to get the hot water
moving. Once it circulates, hot water leaves the boiler, cooler water comes
in. The aquastat in the boiler senses that and turns on the burner to heat
it up. Usually there is about a 20 degrees differential. You may want to
have a technician come out and show you how the system operates.

Check out how well the house is insulated, storm windows, etc. That can
save a bundle on heating costs.
Ed