Watch a Pinnacle Career Institute student demonstrate how to test a flame sensor in a furnace. Video narrated by PCI Online HVAC, Lead Faculty, Bret Doles.
As it heats up? I was taught that unlike a pilot generator that creates voltage as it heats up, a flame rod sensor is used to detect flame via a short to ground thru the presence of the flame as the flame itself can carry current via moisture that is created as a byproduct of combustion that can be read in microamps.
Exactly my understanding of it as well. Or anyone who reads effectively. Also, the 2.4 microamp reading is definitely low. I was taught 3-5, with 3 being low enough to replace. There's nothing "Pinnacle" about this institute 😆
Didn't say what to set your meter on. I'm guessing you put your meter leads in series with the male spade on the sensor and the female spade of the wire?
Hi.....i would appreciate if you could help me with a question related to a igniter..when i check the voltage that Is Is receiving a round a variation on and of ..could be that caused by a faulty pressure switch?
The ignitor (hot surface or spark) will NOT turn on (get voltage) if the pressure switch doesn't close when the inducer turns on. Some hot surface ignitors get 80v from the board, some 100v, etc.. for example old trade furnaces use 80v but the new revised boards (for same trane unit) use 100v. If your ignitor turns on and then the gas valve lighting the burner make sure the flame carries over to all burners (including flame sensor). If it does and the flame sensor is bathing in flame and the burners still turn off use this video to determine if the flame sensor is good. If so it's a possibility a limit switch, gas valve or board is bad. A more in depth troubleshoot would need to be done to determine whether it's either of those parts. If you have voltage to the ignitor and it doesn't "glow" then replace the HSI (hot surface ignitor)
Can anyone tell me why the ua jumps around on occasion while trying to test the flame signal?? This only seems to happen on Lennox furnaces. For example, most times I get a ua reading of 3.9-2.8 but sometimes the numbers will jump sporadically and I can't even get a reading
I would check meter connection with the flame sensor and possibly using the range button if it is an auto ranging meter. The microamp reading will change when the furnace first fires and may fluctuate slightly during operation on some furnaces.
I think you're confusing a flame sensor, where the current is conducted by the flame, with a thermocouple, where it generates a current as it's heated.
I mean if your'e gonna do a video for RU-vid at least make it concise and complete. This happens so often. Just do a little more to make it better. Hopefully helpful criticism not hater criticism.
