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airheatman, HVAC Technician
Category: HVAC
Satisfied Customers: 8378
Experience:  Furnace, A/C and heat pump specialist.
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American Standard TUS100B936A0 Flame sensor, roll out/limit

Customer Question

American Standard TUS100B936A0 Flame sensor, roll out/limit switch, ignitor, and thermostat have all been replace. Still intermitintly
JA: I'll do all I can to help. Tell me a bit more about what's going on so we can help you best.
Customer: For weeks not the furnace will need to be reset, once a lock out code flashed not other codes occur. It clicks and sometimes the ignitor does not glow. Others it fires up and then shuts down like it's short cycling. Kill the power and reset it and runs for a day...sometimes several days other times just hours.
JA: Is there anything else important you think the HVAC Technician should know?
Customer: We visually inspected blower door switch, checked the filter, that no vents were blocked, nothing looks damaged or melted or broken wiring wise etc.
JA: OK. Got it. I'm sending you to a secure page on JustAnswer so you can place the $5 fully-refundable deposit now. While you're filling out that form, I'll tell the HVAC Technician about your situation and then connect you two.
Submitted: 1 year ago.
Category: HVAC
Expert:  airheatman replied 1 year ago.

Being that you have replaced the items and we are not getting an error code such as pressure switch error, most likely a failing board. Intermiitent failure is characteristic of a board going out.They develop stress cracks over time.