HVAC guys in here...

[Tannerm]

Recently noticed that our heater doesn't blow hot air when activwted. If I switch it to EM or Emergency Heat it'll blow hot. Today with it being close to 80, I clicked on the ac. This time it doesn't blow cold... it only blows room temp air. The tstat is a honeywell, and the outside unit is a trane. It's a few years old. I wanna say it's 2.5 tons?

Any help is appreciated.

[slowturbocar]

Does the outside unit even come on? Had a similar problem with mine during the summer and turned out the breakers were showing minimal voltage on the other side of the breaker and no power to the outside unit. Had a problem the year before and turned out the damn NEST was having issue's.

[Tannerm]

She's running. I have her on auto now. Before it was set to "on". The filter will be the next thing I'll try... I gotta sleep all day today and it's Gunna be close to 80 today. This northern boy doesn't fair well in warm weather... especially during sleep time.

[DieselSmoke]

Sounds like the reversing valve. I'm not a hvac guy but I've had two go out and that exactly what mine did.

[Tannerm]

Diesel where is this valve? I do notice thst when my ac is suppose on, the air thst is blowing off the ac unit is cool. I coulda swore that when the ac is kickin, it gives off heat.

[likeitfast55]

Tanner, I assume you have a heat pump by your "electric heat" backup statement. The outside unit needs 110/220 to work. Most condensing units(outside) use 110 for the fan on top, and 220 for the compressor. Just because the fan is running doesn't mean the compressor is. If the unit doesn't cool or "heat", it could be several things. First you need to establish that your compressor is running on the outside.
If it is then next thing to check is freon levels. If that is OK, next thing is to check the reversing valve. Many components to that, the switching solenoid will fail and cause the unit not to pump freon in either direction.

If you have an amprobe and a set of AC gauges, this could be found out in about 10 min.

Yes with the AC portion running, the outside condensing unit will give off warm air, its condensing the freon in the coils inside the unit. Conversely when it is switched to "heat" the outside unit will give off cold air, it is evaporating the freon. The reversing valve switches this freon flow as to you setting the t-stat to heat or cold.

The reversing valve is outside in the condensing unit. Do not fuck with it if you do not know what you are doing. It is a very delicate piece and expensive to replace as well.


PS_ I paid my way through flight school doing HVAC in Louisiana. Had a A/B 5 tons and under license. I haven't done it in over 30 years, but the fundamentals have not changed.