0

I need help troubleshooting Tempstar furnace Honeywell ST9162A 1040 Board

Blower: DC motor Variable speed Speed Control: Emerson X177265620004

Symptom: No Inside blower in Cool mode.

Outside AC is working fine. Inside blower will not work.

Thermostat: Replace new, same issues.

  • Tstat switch set to Heat, and Fan set to AUTO, Heat runs normally: Inside Blower/Fan starts and runs normally. Then, set Tstat system switch to off then Blower shuts off.

  • Tstat System switch set to Off, and Fan set to On, Blower runs normally (continuous).

  • Tstat System set to Cool, and Fan set to AUTO, outside AC run normally, inside Blower did not run then turning Fan to On inside Blower remains off.

enter image description here

enter image description here

Mazura
  • 13,377
  • 1
  • 18
  • 56
Victor
  • 1
  • Did it used to work? – gnicko Jun 10 '23 at 00:10
  • 1
    Does this help? https://diy.stackexchange.com/q/66799/25178 Or this? https://diy.stackexchange.com/q/69989/25178 – gnicko Jun 10 '23 at 00:13
  • @gnicko yes. It did work last year. I read these post and it a bit different with mime. My Blower connect with speed control instead of connect direct to control board, so I do not know how to test blower by pass controller to make sure blower is good or not. – Victor Jun 10 '23 at 03:11
  • "Blower runs normally (continuous)." - I'd assume blower motor and its start/run capacitor are both good, but ECMs are not my specialty. On old ones, AC always hooked to the high speed line, heat was a choice where. Do these have a bypass wire that tells it to goooo ? – Mazura Jun 10 '23 at 22:42
  • "If you make a mistake you could potentially fry your furnace controller." How do you trigger the HVAC with wiring only? "connect R and Y" inside the air handler to eliminate both the thermostat and the wire in the wall as culprits. "start by making sure the thermostat call is reaching the furnace" - "the problem likely lies within the control board." – Mazura Jun 10 '23 at 23:09
  • Note: you have a multi stage unit (which complicates things), and it looks too old to be an ECM, which lends me towards the computer junk in there is shot. And they're not fun to find : https://www.justanswer.com/hvac/a2kas-looking-emerson-variable-motor-speed-control.html – Mazura Jun 10 '23 at 23:10
  • 1
    Hi @Mazura thank you for the suggestion. I connected R and Y on both Tstat and on control board. AC on and run well. I connected R and G fan run but I connected R to both Y and G just AC run blower did not run at all. Yes that is old 2 stages unit with ECM (DC motor, it has 4 wires Red, Yellow, Blue and Green). – Victor Jun 12 '23 at 04:25
  • "I connected R and Y on ... control board. AC on and run well." - So it's the t-stat or its wire. Which doesn't surprise me as its a white wire on Y at the tstat, and red and blue double tapped at the furnace (one of the two is the condenser, but one of them needs to be the white wire from the tstat). Having run it with alarm cable colors doesn't help. - This issue started on its own or after you swapped the tstat? – Mazura Jun 12 '23 at 16:21
  • Y on the tstat needs to go to Y+condensor at the furnace. – Mazura Jun 12 '23 at 16:22
  • .... a whole bunch of those colors don't match up. Need a picture of that wire nut mess, wherever it is. But my god (there shouldn't be two white wires; they used a length of the same stuff inside the wall?). 2 stage and there's no c wire... how hard would it be to pull some 7-wire that's all the right colors? --- or, there's a blue wire behind the tstat that should go to the tstat's Y ? but then why is G, black at the tstat.... – Mazura Jun 12 '23 at 18:48
  • The color of wires at Tstat and furnance’s board is different because wires has been cut and reconnected due to upgrade or other reason I did not know. At furnace end the colors seem correct but it has been conecneted with cables in the wall so they are different. My blower and AC worked last year. I had have pro guys come to clean it last summer too then it did not blower on the first day cold when we turn furnace to heat mode. We called to pro guy and he came and clean drip tray and it has been working well til now. Last week, I turn AC On but blower did not run. – Victor Jun 12 '23 at 20:26
  • I am wondering how to test and make sure speed control, board control or motor failed? My motor is DC motor and there 4 wires Red, Yellow, Blue, and Green. It is match with colors on the output wires of the speed control. Speed control has 125v from control board it was powered in fan on only mode and AC and fan on mode. Speed control also is connect with Control board – Victor Jun 12 '23 at 20:35

1 Answers1

1

Let's summarize.

TH +FA = all runs Heat mode

TF = F-runs Fan only mode

TC + FA = F does not runs Cooling mode

Would say your control board is fine, but it is getting signal not to run.

That would indicate the drip pan water overflow sensor is active. It is ignored in heat mode, it is ignored in fan only mode, but it is used in Cooling+Fan mode.

A quick Test:

Use pice of wire and bridge the Y an G

T - Thermostat F- Fan C- cooling H- Heating A- Auto mode

Traveler
  • 17,239
  • 2
  • 17
  • 41
  • Thank you for the summarize. It is correct! I am newbie and first house owner, so can you please show me where is the drip pan water in the furnace? I’ve looked around but not yet found. – Victor Jun 10 '23 at 03:56
  • Just below the Indoor Fan, it should have a drain pipe coming out. See the white pipe, follow it to find the drip pan, and there should be the level sensor. Once you find it, just unplug it and see if the C+F is working now – Traveler Jun 10 '23 at 04:37
  • "Tstat System set to Cool, and Fan set to AUTO, outside AC run normally, inside Blower did not run then turning Fan to On inside Blower remains off." - it should be in complete lockout then, or actually running nothing but the air handler to melt the block of ice on the coil. Isn't the drip pan water overflow sensor just in series with the call for cooling? So that when it's leaking, it stops the condenser outside from making more water inside. With condenser running and no blower, you're making ice inside, then it locks out and starts dripping water everywhere. – Mazura Jun 10 '23 at 22:39
  • I suspected the high speed line on the blower motor but it's variable speed. – Mazura Jun 10 '23 at 22:39
  • @Mazura however the Fan is running in Fan only mode – Traveler Jun 10 '23 at 23:10
  • That's the thing. It ignores G if it's getting Y.... why. – Mazura Jun 10 '23 at 23:11
  • Thank you so much @Ruskes and Mazura. I looked at my furnace but it seems there is no drip pan and sensor. What I am seeing here just control board, speed control, there is a drip tray as photo in this link https://www.repairclinic.com/PartDetail/Drip-Tray/1013676/2762437. I cleaned it and put it back and then set TC + FO (fan on) blower worked after that I changed FO to FA blower did not work even I turn back FA to FO. – Victor Jun 11 '23 at 05:23
  • @Victor can you post a picture of your thermostat also showing the Fan control switches – Traveler Jun 11 '23 at 07:42
  • @Ruskes here they are https://drive.google.com/file/d/1mrwHCWdsCGLs6iixyg4TGY6gWQ9caipA/view?usp=drivesdk https://drive.google.com/file/d/19w1WwZvRN0wGYYbHasKl43eZLCFCdwyV/view?usp=drivesdk. https://drive.google.com/file/d/1GpbVDrkRjn1ax-W9XjxGowrtHxml-TYC/view?usp=drivesdk TStat: White-Rodgers https://drive.google.com/file/d/12oPcYMVxrVkC6I2Ctmy6Oty-N8zdqpIh/view?usp=drivesdk – Victor Jun 11 '23 at 12:31