I have an older Jarco Boiler 700,000 BTU built in 1981. It runs floor heat for 7 bays. Recently it has started to short-cycle on/off every 5 seconds. That's 12 times a minute, 720 times a hour. I hope I don't break anything allowing this to continue. I have replaced the low temp and high temp thermostats and overridden the flow sensor but still the burner turns itself off after only 1 or 2 seconds of igniting each time. There is no flame sensor on the unit that I can find. Gas flow appears to be good. I have also swapped out the igniter controller.
When the system first turns on from a cold start, the boiler will run for about a minute until it goes into this short cycling issue.
Thanks in advance for any ideas you might have.
When the system first turns on from a cold start, the boiler will run for about a minute until it goes into this short cycling issue.
Thanks in advance for any ideas you might have.