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Look on blower housing for control board and see if we have a light flashing.If so tell me the pattern of the flash as that will tell us where to start troubleshooting
Does it change when furnace fails to light? It should give us an error code such as two short flashes followed by 2 long flashes
Does fan stay on or run for 90 seconds and shut off?
Does the little vent motor ever come on? If not do you have ammeter to see if it is getting power on call for heat?
You may have a zone system if you have two thermostats, but we still should get heat if this is the main thermostat.I actually have a phone call and need to step away.I will open to other experts while I am gone and will check in when I et off phone.
I have opted out of the question to see if perhaps other experts may have more information and can assist.Please do not rate or reply as that will send question back to my desk. Please stand by to see if another expert can assist further.
OK I am back. Can you get a volt meter so we can do some troubleshooting? The firdt thing that has to happen is we have to get power to the vent inducer motor.
Let me know when you are online.
Tomorrow afternoon is fine.
Ok on furnace control board where thermostat wires hook up, do you see a C and an R terminal?
OK what I want you to do is this.first make sure we are getting 24 volts between that R and COM on board.I feel sure we are but want to verify.
Excellent. Next I want you to unplug the wires at the little inducer vent motor. Put meter probes into the connector that you unplugged from motor. Power off then back on to reset board. Then call for heat and see if we get 120v at the plug. (Door button of course needs to be in or panel in place to hold button in.)
But error light is staying solid?
OK on call for heat, the board checks low heat and high heat pressure switches to verify they are open. If so, inducer should start.If not we should get either a 31 or 32 error code.
Lets do this. On furnace control board lets jumper R to W and see if inducer will start.
OK let me know if that changes after 90 seconds
OK that implies the issue is with the thermostat rather than the furnace. Has thermostat been replaced since heater last worked?
Jumping R and W bypassed the thermostat. Thermostat is not signaling furnace to come on.Do you know if you have a heat pump outdoor unit?If unsure give me model on outdoor and I can tell you.
Ok tell me what thermostat wires connect where on furnace board.Then lets move to thermostat. Remove front of thermostat and give me model on the thermostat, then tell me what wires are connected where.
A picture would save a lot of typing if you can take a pic.
Send me one also of thermostat with front removed.
Next tell me model on thermostt
Next tell me model on thermost
Lets look at the dip switches as shown on page 18/19 here
1 should be to right
Ok lets do this. Remove the Red and white wire at thermostat and touch them together or loosen screws and move white over to the Rh slot with red and see if furnace will come on.
Remove the one at furnace. What we are doing is basically same thing but at thermost
Have to step away just for a few, If we can get heat to come on doing this, the thermostat is definitely the problem Try a hardware rete,If that doesn't help we will need to replace thermostat.I will be back in just a few minutes.
On smatzone board lets check between C and W and see if we have 24v?
Ok it seems like we may have a couple of things going on. First of all. let me say the blower on for 90 seconds is normal when turning power on to furnace.But then when the inducer comes on and igniter does not light we should get an error code on the board telling us what failed in the circuit by giving us a flash code such as three long and one short flash or something.
To be honest with you I am not real familiar with the smartzone board and how it operates. Rather than mislead you I feel it fair to you that I opt out and see if maybe another expert familiar with the board pick up here.
Be sure if another expert picks up the question to explain that you have this smartzone board and make sure they are familiar with the board and how it works in conjunction with your furnace.
I will keep monitoring the question to see if anyone picks it up or if you reply with a code.
PLease wait to see if we can help before rating answer.
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Possibly but I am still concerned why you are not getting an error code when ignition fails
Makes sense .Please let me know.
I am not real familiar with that board but knew we weren't getting signal all the way to furnace.Thanks for letting me work with you.If my answer has been polite, professional,and thorough, please click one of the ratings before you go. If you still need help let me know!.Expert is not paid for assisting you until you rate answer.Feel free to follow up for 30 days at no additional cost. Bonus always appreciated if you feel justified.