Intermittent failure

Jesse J

My steam boiler (Dunkirk) has been occasionally not firing, here is what happens. Thermostat calls and opens damper, then nothing. If I turn the power to the unit on and off a couple of times, or run the thermestat up and down a couple of times the boiler will "take off", and cycle for a couple of days with out fail, then it will get hung up and it's usually in the middle of the night. At first I thought it may be a loose connection and tightened all connections, no dice, I then thought it may be the IP control which was a Honeywell "Non 100% Shutoff IP NG only" Model number S8600F-1000 which I replaced with a Honeywell S8610U-1003 (old one now obsolete) worked well for a week and I thought my $100 was well spent until this past weekend when the problem returned. I turned, again, to loose conections and thought I had found one I missed before the boiler cycled good all night but was off again this am. Do you have a direction to send me in?

Unknown

Jesse

My steam boiler (Dunkirk) has been occasionally not firing, here is what happens. Thermostat calls and opens damper, then nothing.

WHEN THE DAMPER OPENS DO YOU HAVE 24 VOLTS AT TH(W) AND 24 VOLT GROUND ON THE MODULE? IF IT IS INTERMITTENT THEN EITHER REPLACE THE DAMPER OR SEE IF IT IS HANGING UP AND NOT OPENING FULLY.

If I turn the power to the unit on and off a couple of times, or run the thermestat up and down a couple of times the boiler will "take off", and cycle for a couple of days with out fail, then it will get hung up and it's usually in the middle of the night. At first I thought it may be a loose connection and tightened all connections, no dice, I then thought it may be the IP control which was a Honeywell "Non 100% Shutoff IP NG only" Model number S8600F-1000 which I replaced with a Honeywell S8610U-1003

THE S8610U IS A RETRY 90 SECONDS OFF 5 MINUTES SO IT SHOULD KEEP RETRYING. THE FACT THAT IT IS DOING THE SAME THING WITH THE NEW MODULE TELLS ME IT WAS NOT THE MODULE.


(old one now obsolete) worked well for a week and I thought my $100 was well spent until this past weekend when the problem returned. I turned, again, to loose conections and thought I had found one I missed before the boiler cycled good all night but was off again this am. Do you have a direction to send me in?

IF YOU ARE GETTING 24 VOLTS TO THE MODULE WITH THE DAMPER FULLY OPEN DOES IT SPARK AND DO YOU HAVE 24 VOLTS PV TO MV/PV?

DOES THE PILOT LIGHT?

DOES IT STAY LIT?

DO YOU KNOW HOW TO CHECK MICROAMPS?

DO YOU THEN HAVE 24 VOLTS MV TO MV/PV?

DOES THE GAS VALVE OPEN AND BURNER COME ON?

This is a step by step through the sequence. Let us know how you make out.

dan holmes_2

sounds like bad pilot,if you cannot trouble shoot try changing the pilot it is less then the s8610.

Jesse J

damper not opening

Finally had another failure, damper hanging up (not fully opening.

Thanks for the tips
Jesse

mike y

thermoplie

hot air system /propane /thermopile / no pilot changed themopile unit ran ok 1 week later no heat /have pilot jumped thermostat out unit fired ok changed thermosts ok /2 weeks later same seniario jump therm unit fires ok ? any input thanks

CHARLES_4

Not sure what type of system you have. If it's a millivolt system, check your t'stat for compatibility. The anticipator has too much resistance for a millivolt system, hence the ability to make the system work when you by-pass t'stat. Check for excessive resistance throughout entire circuit.
Also, a lot of older millivolt valves were diaphragm-type. If so, check to see if vent tubing is clear, esp @ pilot end.