Have HVAC Questions? Ask an HVAC Expert for Answers
Let me ask a few questions.
1.Is this a new installation or did everything used to work fine?
2.Do you have a volt meter for troubleshooting?
3.Do you hear the gas valve click when igniter lights?
4.Is there a flashing green light on furnace control board in blower compartment?
if you are hearing the gas valve click, the issue is most likely a gas pressure problem. Make sure gas cock is turned IN line with gas pipe and switch on gas valve is on position.
Flame sensor does not come into play until you have a flame for it to sense.
OK if we are not getting ignition, there is a light in blower compartment on board that should be blinking.Count the number of flashes between pausing and that will point us in direction to troubleshoot.
Control board will be mounted to blower housing in blower compartment,Should be a small window too look in so you don't have to remove the panel.
OK do you see the light and if so is it on solid?
OK do this. Remove the bottom panel. Then hold or tape the door switch hat panel was holding in and lets locate the light on board.If furnace as power(which we know it does) the light will be either solid or flashing)
Light does not come on if you push the door switch button IN?
OK keep door switch held or taped down and call for heat at thermostat.If burners do not light, the little light should blink giving us a code such as 2 blink pause or three blink pause.
Both doors can stay off right now but door switch has to be in
OK if only one burner lit, you may may have low gas pressure or burners need to be removed and cleaned.THe gas has to go from one burner to the next through little feeder tubes on burners.If all burners do not light, the flame sensor does not sense flame as it is in front of last burner to light.I would start by cleaning burners.See below:
Yes. Follow instructions in link I sent.
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Try this link
If it does not, we have a gas pressure issue.Either not enough pressure into valve or out of valve.Do you have any other gas appliances and if so are they working properly?
Thermostat would not be the issue as we would not even get the one burner.If burners are clean, I would have the gas vale checked.You can do this yourself ,but would need a manometer or gas pressure gauge to do s. Valve has a fitting on inlet and outlet side to do this.WE should have 5 to 7 inches water column in and 3.5" out.Gas valve diaphragm could not be opening all the way allowing enough pressure out of valve to light all burners.
We should have 5 to 7 inches water column in and 3.5" out.Gas valve
Sounds good. Make sue to get a gauge designed to read gas pressure (Water column) not psig like you would use to check air pressure.
You will want to check the pressure as son as the igniter lights when that one burner lights.
We will go from here