Weil McLain gas steam. Sporadic heat

sonicboomin

Hi, my boiler for last few days have been having issues starting up. I thought it was a bad thermostat so i changed, same issue.
When thermostat calls for heat, it makes click sound, i check basement boiler. Burners not on. Pilot is on, I noticed damper opened. LWCO is green, plenty of water. Damper stayed open entire time since thermostat called for heat. If i power off thermostat then on or lower temp and bring up it will go on and flames come on. This happens sporadically.
PSEG was here two weeks ago, he cleaned out dirty water and did lower output a little.
Im Stumped

Jamie Hall

Ah -- has this been happening more or less since PSEG was there? I'd get them back...

If they can't fix it, then you'll need someone with the necessary measuring devices -- and the skill to use them to troubleshoot this. There are a number of things which could be amiss.

sonicboomin

Pseg was here 2 weeks ago. This started 3 days ago. They scheduled to come again tomorrow 

JUGHNE

Is this a standing pilot or is it ignited with each call for heat?

sonicboomin

Standing pilot

JUGHNE

The tstat opens the vent damper, when it is in the open position (the shaft is parallel to the flue pipe) there is a small end switch that sends power to the gas valve.

When the damper is open, look for a small switch on the motor that states "manual open" or something to that effect.
That should close the end switch for firing the boiler.
The damper must stay open full time for the boiler to light.

You may need a new damper motor, the end switch may be hit and miss as far as closing when it should.

sonicboomin

Thanks all. Yes and I noticed the damper was open however burners were not firing that is the issue. 

Erin Holohan Haskell

@sonicboomin, I've combined your two posts into one here. Thanks!

neilc

#pigtail

go bang on your Ptrol,
and post a picture of it and the pigtail,
raise the setting one turn, temporarily

pigtail is clogged?

JUGHNE

If the ptrol was not closed there would be no call for heat and the vent damper would not open.

Did the OP move the switch on vent damper to manual on and then get heat???

neilc

JUGHNE said:

If the ptrol was not closed there would be no call for heat and the vent damper would not open.

ok, good point,
but things never get wired funny either, right?