Boiler turns off randomly

Northmen23

I've had two different repair people out . No one seems to know what the problem is. the problem has gotten steadily worse. The boiler runs 1-10 minutes then shuts off. Not responding to thermostat. when i shut off electricy and turn back on it seems to work. then shuts down and wont work at all.

JohnNY

If it re-starts when power is cycled then the problem is in the ignition circuit.
All the other operating controls would be unaffected by de-powering and the safety controls have a manual reset or thermal fuse. Say these words to the next person that tries to fix and see if they can narrow the problem down to an ignition module, flame sensor/spark ignition cable, or cracked porcelain on the pilot assembly.

Northmen23

thanks for your help i will relay your message

Lance

May I add this observation. When a unit resets with power on/off/on, it can often reset limits, or the condition causing the failure has disappeared. Hi limit trip, did its job, energy off and it cools down. But won't restart because the mfg wants the unit to be checked by a person for the cause.
But in 1 to 10 minutes something has to be found to find what is the trigger. A broke wire touching is most difficult to find especially when heat is a factor. Pressures and conditions need to be monitored to find out what is changing. Sure the light bulb may have failed on its own, but what if its the circuit, the fuse or a switch that decide to be off? Draft door switches, blower pressure switches, even the control modules themselves can cause problems. Isolate and troubleshoot, divide or bypass sections to find the cause. How about this for a problem: Spider web in a gas pipe, or sand in a gas main affecting combustion limits. Or how about a drop in gas pressure by the utility? By pass the thermostat wiring and wire a switch direct to troubleshoot. This is where a good diagnostic worker comes in handy.

kcopp

What boiler is this? Gas? Oil? Brand?
Model?

hot_rod

need to know what type of boiler. Mod cons for example will cycle like that if the main circulator fails. They heat quickly and trip high limit, cool down and repeat.

mattmia2

What kind of thermostat is it?

JohnNY

hot_rod said:

need to know what type of boiler. Mod cons for example will cycle like that if the main circulator fails. They heat quickly and trip high limit, cool down and repeat.

Yes, this. I made several assumptions about the boiler being an atmospheric, standard efficiency unit.