View Full Version : Slant Fin Sentinel Boiler not Fireing

11-07-2009, 02:07 PM
Hi folks, nice forums.

Seems my boiler will not start up anymore.
I had it working fine for 3 days, then it got warm and I lowered the thermostat down so it was off, but, now it wont fire.

I hear the clicking and the water running when turning up the thermostat, but it never fires. The pilot light is off and does light when I manually light it but it wont stay lit. Yes gas is on.

I do not know if it is an always on pilot light or the one that lights by sensor when needed. Anyway to tell?

It will be getting down low forties tonight and being a do it myself type would like to know where to start to diagnos the problem, any ideas would be greatly appreciated,
Thank you

11-07-2009, 03:18 PM
It sounds like you have a standing pilot light. The burner won't light unless the pilot is lit. The pilot won't stay lit unless the sensor that sits in its flame says it is lit (i.e., it gets hot, and sends a signal to the gas valve). So, first, make sure that the sensor is in the flame of the pilot. It might also be dirty, so clean it off, or reposition it if required so it is in the pilot flame. If that doesn't work, if you have a multimeter and the manual, you can test the sensor (thermocouple) to see if it is within specs. If not, you'll have to replace it.

11-07-2009, 04:17 PM
I have a fluke meter I use from my auto mechanic days.
The manual is handy as well.
What should I test (amps,volts,ohms) for and will the manual give me the proper stats to go by? Usually that stuff isnt in the owners manual.

Thank you

11-07-2009, 05:59 PM
Woah thats me in the avatar!
Kind of, thats my profession.

Love it thanks.

Ok, thermocoupler is bad, new one is around $10 so I will get a new one and see if that helps. My neighbor does this for a living and keeps the company truck at home, he may have one on the truck, if not we have a great supply store on the main road.


11-08-2009, 04:01 PM
Let us know how it went !
Good luck