boiler wont fire

Boombadi1

i have a smith boiler that wont fire i am able to jump out motorized damper and make gas valve fire  with a call for heat this will not happen i then remove jumper and gas valve shuts off but pilot stays lit after circ. has lowered boiler temp the the gas valve will not refire to heat again

Tim McElwain

I assume you mean

you are jumping out the "vent damper" located in the flue pipe, is that correct? This could mean that the damper may not be opening all the way or it has a defective end switch in the damper. In that case replace the damper.



What I do not understand is when the jumper is removed you say the gas valve shuts off but the pilot stays lit, that should not be happening if it is spark ignition. What is the make and model number of the gas valve? Is this a spark ignition system or a thermocouple? If it is a thermocouple then the pilot will stay lit when the gas valve shuts off, however if spark ignition both main valve and pilot should shut off when the call for heat ends.



The key to all this happening is that the vent damper has to open fully every time or the burner will not fire, by jumping it out you are bypassing the switches in the damper.

Boombadi1

boiler dont work

thanks for your reply i guess to make things more clear my main issue is that my boiler will not maintain regular standby temp. also the reason im asking for ur advise is because this boiler went under water and ive worked in the field long enough to know that if it got wet then replace it so i did jus that all of the electrical controls on this unit are brand new including circulator,gas valve,control center,high limit,and roll out switch i dont know why the boiler cant maintain any heat when there is no call for heat  but when there is a call for heat the circ. pump runs but there no hot water to circ. and the gas valve doesnt light. this system has standing pilot gas valve.

Tim McElwain

If i understand you correctly

the controls were replaced but not the boiler, is that correct?



When this boiler does not fire do you have 24 volt power to the gas valve?



Has the transformer been replaced and all the other electrical wiring etc?



Do you have a multi-meter? If so check to see were you lose power when the units does what it is doing.

Boombadi1

yes all electrical components

yes changed transformer   and no i do not have 24 volts on gas valve  only 12  volts on one leg but what i dont understand is that the circulator run when theres a call for heat i dont know what im missing

Tim McElwain

Give me some

idea of what you have for controls. The circulator could run as it is perhaps brought on by a call for heat through a relay, is that correct? If so what is the make of the relay? Does the relay also power the gas valve? If you put your meter directly across the coil on the gas valve do you read 24 volts? If you do not then what ever is in series with that valve is holding the valve off.



This by the way is why FEMA and GAMA and all the furnace, water heater and boiler companies want the entire appliance replaced when flooding occurs.