Weil-MClain
CGM-25 Series 8

Woke up this morning to a cold house, after poking around a bit. I switched the lever on the High limit Control from Auto to Manual and the burners ignited right away.

I am hoping to get some insight.

What would cause it to stop igniting while on auto?

Why do the burners automatically ignite when this switch is in the Manual position?

is it dangerous to keep the system running in manual mode?

Thank you for the help.

Is there any other info about the high limit control that you can give us? Is there a Honeywell sticker on it? It sounds as though the boiler thinks the high limit has already been reached, and that's why it won't fire in auto. I'd like to be able to see what's going on with the H.L. control though, to be able to tell you more.

Paul48, from all vantage points I cannot see a make of the High limit control. currently the high limit temp is set at 210 degrees F.

Low battery on the T-Stat? Put it back on Auto and jump the T-stat connections at the boiler.



Edited 1 times.

Hello Paul48,

I have one battery operated T-stat and one which doesn't have a battery. The T-stat is not indicating a low battery... anyway. I do not know how to jump the connection, therefore I will contact a local service tech.

I believe to turn on the heat you would look at where the thermostat wire connects to the furnace. You will see the wires connecting to some screw-down terminals. Using a piece of wire to connect the red and white wires should turn on the heat regardless of the thermostats.