Steam Boiler Stopped Firing in the mornings?

nybigapple

Tekmar 279 controller on a Weil McLain LBG boiler, the last 2 mornings including this frigid one, I've woken up to no heat. Checking the steam boiler, the Tekmar shows the call for heat, but the boiler isn't running.

There are no errors on Tekmar screen, and the water level is fine. Testing the LWCO at this point, I can hear the gas on restart, but the flame doesn't start. Resetting the power to the boiler seems to clear up the problem for a little while. The boiler runs for the rest of the day and is operating normally. But this problem seems to come back regularly now, usually after the setback of not running for a few hours at night.

What are the likely causes and what should I check?

JohnNY

Flame sensor? Compromised pilot assembly/components? Faulty ignition module? Condensing/dripping heat exchanger? Clogged pigtail?

clammy

Has your boiler been serviced . I would start at checking your pressuretroll pigtails and any and all low water cut off probes also instead of resetting try jumping out the tt terminals on the boiler if it start then the issue I said w the tekmar . When faced w any boiler controller of any type I usually cut to the chase to eliminate controls outside of the boilers safeties ,just helps you get to the issue w out having to fool around w possibly re programming a boiler building control . Life is hard so think first and make sure the boiler isn’t off on one of it safeties first if so there’s your answer if not chk that tekmar if boiler doesn’t fire when control is calling . Sometimes guy starts use isolation relay and separate transformers ,so look around and have your electric meter handy . Peace and good luck clammu

nybigapple

Thanks, this gives me a starting point. I'm not sure why it seems to only happen during the night time set back. But I'll start checking out some of the things you've both mentioned.

TonKa

nybigapple said:

I'm not sure why it seems to only happen during the night time set back.

My money is on the pressuretrol and/or pigtail.

Would you say your boiler is not oversized? If so, chances are your system's pressuretrol only comes into play during recovery from a setback. As a rule, this is good, but if your pressuretrol is acting up you will get the symptoms you describe.

clammy

Just a added thought , set backs on most steam systems is when you will see issues like low cycling on low water due to pick up factor and possible use of a cycle guard lwco . Lack of main vents and old semi working radiator vents not working ,venting the main properly and cycling on pressuretroll ,Is yet another issue .also check to make sure that if equipped w a flue vent damper that it is opening on a call for heat . How much of a set back are you using degree wise ? Large set backs usually cause issue w steam systems being they where never designed for that type of operation and most usually have some issue w large set backs and cold temps just my experience . Peace and good luck clammy