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Phil
Phil, Mechanical Engineer
Category: HVAC
Satisfied Customers: 6022
Experience:  Retired HVAC/ Electrical & Boiler contractor. Industrial
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Thanks here. We just changed the flame sensor and the

Customer Question

Hello, Thanks for being here. We just changed the flame sensor and the furnace just cycles and the burner will not fire up.
JA: Thanks. Can you give me any more details about your issue?
Customer: The furnace will cycle and there is a clicking noise and it just turns on like it wants to start but the burners will not fire up
JA: OK got it. Last thing — HVAC Technicians generally expect a deposit of about $18 to help with your type of question (you only pay if satisfied). Now I'm going to take you to a page to place a secure deposit with JustAnswer. Don't worry, this chat is saved. After that, we will finish helping you.
Submitted: 1 year ago.
Category: HVAC
Expert:  Rick replied 1 year ago.

What is the brand and model number of your furnace?

Customer: replied 1 year ago.
Armstrong ultra 80
Expert:  Rick replied 1 year ago.

Ok, I don't have access to Armstrong specs. I'm going to open this up to my colleagues so one of them can help. Please don't respond (even to acknowledge this post)until you get a response from us. If you respond first it will only delay your answer.

Expert:  Tim H. replied 1 year ago.

Hi, I'm Tim and I'm an HVAC expert here to assist you with your questions. Please provide all information I request as it makes it more difficult to troubleshoot something when I'm not there onsite. Essentially, you become my eyes and ears. Thanks for the opportunity to help. At the end of our dialog, you will have a chance to rate my service, but please wait until we are finished and you're satisfied you have all the information you need. Please be patient as many times we work with several customers at once.

Did you still need help with this? Do you have access to a voltmeter and know how to use?

Customer: replied 1 year ago.
We have gone through the check list and we believe it is the flame sensor. So we ordered it and will replace it on Thursday
Expert:  Tim H. replied 1 year ago.

If the burners are not even coming on at all, it would not be the flame sensor.

Customer: replied 1 year ago.
Oh ok they are not. What would be the problem please
Expert:  Tim H. replied 1 year ago.

You say the hot surface ignitor comes on, correct?

Customer: replied 1 year ago.
When you turn it on the only thing that happens is clicking sound by the flame sensor
Expert:  Tim H. replied 1 year ago.

Your furnace has a hot surface ignitor, correct? An element that glows bright orange and lights the burners?

Customer: replied 1 year ago.
I would like for you to talk to my grandpa he knows what is going on with it although it is in my house how can I have you to connect I will pay but he is not with me now
Expert:  Tim H. replied 1 year ago.

Just post back here whenever he is available to chat.

Customer: replied 1 year ago.
no our furnace does not have a hot surface ignitor. there is no bright orange element that lights the burners. it only has a flame sensor with an ignitor.
Expert:  Tim H. replied 1 year ago.

If there is no bright orange glow, it could be that your HSI (hot surface ignitor) is burned out (very common). This would also explain the click you're hearing and no burners lighting.

Expert:  Tim H. replied 1 year ago.

Can you take a clear picture of the wiring diagram on the unit and upload here?

Customer: replied 1 year ago.
is this what you need?
Expert:  Tim H. replied 1 year ago.

Yes, so this tells me you have spark ignition. And you are getting no spark? Does the inducer motor (small motor at the top of furnace) start on a call for heat?

Customer: replied 1 year ago.
there is no spark. and yes the inducer motor starts when we turn on the furnace.
Expert:  Tim H. replied 1 year ago.

Get your self a voltmeter, set to "volts AC" and put one probe on 24v (GND) and the other on 24 V on ignition module. Turn on heat and shortly after inducer motor start, we should see 24 volts AC. Let me know what you find.

Customer: replied 1 year ago.
i am not currently able to check the voltage right now. I am not at the location where the furnace is and will not be able to check it out in person until Thursday. Would it be possible to continue this conversation on Thursday when I have access to the furnace?
Expert:  Tim H. replied 1 year ago.

Yes, that will be fine.

Customer: replied 1 year ago.
okay thank you for your help so far. I will talk to you thursday.
Expert:  Tim H. replied 1 year ago.

great!