One-Pipe Steam Continuous Pilot - Keeps firing but won't heat!

Scott Reid

My 1991 Dunkirk Plymouth Steam Series 2 Model PVSB Continuous Pilot Gas-Fired Steam Boiler:
*The water level is appropriate
*Cut-in set at approximately 2psi
*Vents have not been problematic
*Thermostat is newer (Honeywell)

Problem:
Thermostat set at 68, but heat hasn't been working since yesterday and the current temperate in my house is 55.
I've reset by cutting the power and leaving unit off for 5 minutes and lowered thermostat to lowest setting.

What the unit is doing:
The boiler will intermittently continuously fire (much like when there isn't enough water in the unit and it's challenging the lower water cutoff) but never stays on long enough to create heat.

Any ideas?
Thank You iI Advance,
Scott

scrook_2

Could be...

a problem w/ the low water cutoff (float type -- that requires blowdown, or a probe type?), could be a problem w/ the gas valve, could be the vent damper, could be a blocked flue or chimney, could even be a gas supply/pressure issue, or might be something else.

Pressure's a little too high at 2 psi also, should be 1 psi or a little less, but that's a differant issue.