Gas burner for steam boiler turns on-off repeatedly

Jim Bennett

you are having a delayed ignition. Not a good situation. You need to have it looked at by a service tech ASAP.

Jan_4

Gas burner for steam boiler turns on-off repeatedly

My husband and I, the 60-year-old virgins of steam heat, need help with this new (old) system -- more help than Dan's wonderful book for amateurs can provide.

The gas burner firing our boiler (HydroTherm 1980)doesn't shut off properly when water is low. (Cutoff is McDonnell 67G.) It goes off for a few seconds, then comes back on with a terrific loud gaspy WHUMP that shakes the (1935) house, and it repeats that cycle a number of times before finally shutting off for good. (I don't know how many times, because when I caught it in the act I added water instantly. But I have heard/felt this sound before, in our 3 years in the house, and thought it was noise in the pipes.)

The thermocouple failed recently and was replaced. I didn't see this happening before that, but I heard the same noises before, so I don't think that is the cause.

The other information is probably incidental, but here's all I know. Yes, we lose water too fast when the heat is on full; have to add it every three or four days. No idea where the leak is; the basement ceiling is mostly finished, some with plaster and some with drop-in panels, and the only stain is a spot that is no longer leaking.

Yes, we blow down the valve every week. The heating itself is pretty well balanced, and pretty quiet. But this burner thing is scary. (Or not? You tell me.)

Thanks, Jan

Jan_4

Thanks, that sounds right, and I'll call for help right away. But is it just a burner problem? It doesn't do this when the burner fires up normally in response to the thermostat. It only does it (that I've seen) when it's trying to turn OFF in response to the low water cutoff. That's why I wonder if that device is also involved somehow.

don_185

Could

Could also be the pigtail.

Mitch_6

you should to a full check up

clean the low water cut off, clean the pig tail, inspect and clean the combustion chamber. If ignition is delayed check the gas valve, check the flue. If you are loosing water you also may need to check the boiler for a leak above the water line. You can be loosing water from blown vents also. This is work for a person that knows what they are doing not a home owner.

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Jan_4

Hey Mitch,
Don't worry, I wasn't planning to do it myself! I just like to know how things work. And hey, we're in Auburndale (Newton), right in your neighborhood; I'd love to have you look at it if it's not too small a job. (Your ad was a bit intimidating.) Shall I call tomorrow? Thanks, Jan

Mitch_6

We do service to have you checked our web sight.

Not to run out and condemn your boiler now but I have had issues working on the older hydrothirms in fact they tend not to do well on carbon monoxide tests. If we do a full cleaning and combustion analysis you may wind up with a new boiler or may not but if I had to bet.

Check the co section of our web sight for the information and authorisation form. you can also get our direct E mail address for scheduling information if you want.

Mitch,

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