this post was submitted on 28 Jul 2023
0 points (NaN% liked)

Home Improvement

9008 readers
54 users here now

Home Improvement

founded 1 year ago
MODERATORS
 

I have a PTAC unit in the room above my garage (Amana PTH123A35AC) that I'm trying to connect a thermostat (Honeywell 50018270-001) to. These are my current connections:

| PTAC | Thermostat | |


|


| | B | B | | C | C | | GL | G | | R | R | | W2 | W | | Y/W1 | Y | | GH | Unused | | Unused | O | | Unused | Rc |

The only thing that's not working is the cool setting. Heat and the fan are working fine. I have tried connecting R to Rc and B to O, but neither worked. I'm fairly certain I have something incorrectly wired here, but I'm just not sure which connection.

PTAC Serial Number Decoded:

  • PTH: Standard Heat Pump PTHP
  • 12: 12,000 BTU/h, 60Hz
  • 3: 230/208V, 60Hz, 1 Phase
  • A: First Design Series
  • 35: 3.5 kW (230/208V)
  • AC: Standard Model

Does anyone have any ideas as to why the cool setting isn't working?

top 1 comments
sorted by: hot top controversial new old
[–] [email protected] 1 points 1 year ago

Update for anyone who finds this post.

I think this was the wrong thermostat for this type of AC. I went out and got an Ecobee to attach to the unit and it’s working great! I did have to call Ecobee to find that I had to change the O/B setting from its default but it’s working like a charm now!