Boiler often will not ignite when thermostat calls for heat

big_giant_house

We have a residential steam boiler on an 1895 one-pipe radiator system.  The boiler dates from the 1970s or '80s.  We have had repeated problems with the boiler not igniting when the thermostat calls for heat.  I did adjust the thermostat to the steam boiler setting, but I wonder if there is some issue with it still.  This morning, the temps were down five degrees below the "hold" setting on the thermostat and the boiler exhaust fan was going without the burners working.  This means the thermostat called for heat, there was a buzzing sound as it tried to ignite, but no ignition.  We had a part replaced last year to take care of this, but it is doing it again.  When I get home and it is fifteen degrees below the hold setting, it will fire right up.  This often happens at the beginning of the season and end, when the temps are moderate, but today was 20 degrees outside.  Any ideas?  Rhonda

nicholas bonham-carter

cold house

is the ignition system at fault, or is it something in the thermostat?  is the thermostat in a good location? are you using a setback? will the thermostat maintain a fixed temperature when setback is disabled. setbacks shorter than 12 hours may save little energy, as the boiler has to work so hard to heat everything up. try having no setback for a while, and see what difference it makes.

what part was replaced? --nbc

big_giant_house

Boiler often will not ignite when thermostat calls for heat

We set the thermostat to "hold" and just keep it set all the time.  I can say that there is a buzzing noise at the boiler when I make an adjustment to try to nudge it to start again.  So, I might turn the heat off and back on at the thermostat and it clicks there and then at the boiler there is a buzzing, which is followed by heat sometimes. Usually this does not happen immediately.  I have to go to the basement and turn off the power to the boiler a few times.  Each time I flip it back, it tries to ignite again and eventually does start up.  Also, I am assuming when the power vent comes on down there, it is because the furnace called for heat.  So the power vent just runs without the boiler working at times.



I don't remember the part we replaced, but I think it was probably related to the ignition.  I also remember at one point there was fail-safe switch that needed replaced because it kept indicating to the boiler that the water was low, so it would not start up.  The thermostat is in the middle of the house and does show temps lower than the hold temp while there are problems getting the boiler going.  My normal contractor seems to have left the area over the summer, or I would ask him about the part (and to come repair the boiler).  Oh, and the boiler did start up (house was at 57 degrees, hold temp 68 degrees), but only after the process described above . Thanks for your response!  RC

nicholas bonham-carter

boiler professional

try the find a contractor button above to see if someone is in your area. search by state, and not by zipcode what is your area?.--nbc

BobC

Get this fixed now

This has to be looked at before you end up having an explosion due to delayed ignition. The boiler should be cleaned and tuned every year to keep it working correctly.



The ignition transformer could be going bad or the electrodes could be fouled. Get it looked at before we read about you in the paper.



Bob

big_giant_house

Thanks for the responses

Thanks, I appreciate the responses.  I'll just shut down the boiler until we can get someone to look it (we have gas forced air upstairs).  We do call the service person annually, but he seems to have left the area this summer, as I cannot locate him and all his numbers have changed.  I have had difficulty locating anyone to work on steam here.  I've tried all the links on this site, but I'll keep looking.  

big_giant_house

Western PA

We are in far western PA, two hours from Cleveland, Pittsburgh and one from Erie.  The Cleveland folks I talked to are not licensed for PA.  The Pittsburgh ones do not come this far north.  There is no-one in town I have found so far who has a lot of experience with steam, but I'll keep looking.  Thank you!  

vaporvac

faulty gas valve?

 Glad to hear you just shut it off. I had a similar thing happen last year. My gas valve was sticky and would fail i the shut position and then just suddenly open.  I was told it was leather and had just worn out and couldn't be repaired. It could also fail in the open position which isn't very good. I also had delayed ignition due to rusty burners. Glad I had those fixed in view of the recent explosions here in Ohio and Indiana.