The pilot light is lit, the
thermostats are up as high as they go, you have power
and the boiler is cold.
A quick overview, You have all of
your thermostats turned up as high as
they will go. You have 120 ac volts
power or you are assuming you have power
Your pilot light is lit.
Your gas control knob or dial is turned
to the on position and your boiler is
A number of things can cause a boiler
with power and a lit pilot light to not
This is not in order of likelihood, just
a list of possibilities.
1Your thermostat is defective.
2 Your 24 volt transformer is defective.
3 Your zone valve end switch or switches
are defective or the wires from them are
4 A spill switch has tripped.
5 A roll out switch has burned out
6 Your gas control valve is defective.
7 Your vent damper is not opening or it's end switch is not showing that it
8 A low water cut off is showing low water and preventing the boiler from
9 A secondary aquastat is defective.
10 Your primary aquastat is defective.
11 Your relay is not pulling in. or is defective.
The above list shows the most common possible causes for your problem.
Many older boilers do not have spill switches, vent dampers, roll out switches,
low water cut offs or secondary aquastats. This alone is a good reason to replace your boiler.
Please notice the images below click on the image or text below to see instructions on
how to test to see if that is causing your problem.
PLEASE don't go changing parts randomly in
hopes you will solve the problem by chance, if
this is too hard for you please stop and let me
help you with the
Open Dialog Service.