Rth230b blows cold air when set on heat - Honeywell Programmable Thermostat Heater

It sounds like your PTAC (packaged terminal air conditioner) unit is malfunctioning. When the thermostat is set to heating mode, the PTAC should be blowing warm air, not cold air. There are a few possible causes for this issue:

1. The PTAC may be low on refrigerant. If the unit is low on refrigerant, it may not be able to properly heat the air.
2. The PTAC's reversing valve may be stuck in the cooling position. The reversing valve is responsible for switching the flow of refrigerant between heating and cooling mode. If it is stuck in the cooling position, the PTAC will blow cold air even when the thermostat is set to heating mode.
3. The PTAC's heating element may be malfunctioning. If the heating element is not functioning properly, the PTAC will not be able to heat the air.

I recommend contacting a trained HVAC technician to diagnose and fix the issue with your PTAC. They will be able to determine the cause of the problem and repair it properly.

Its probably not the thermostat. The air conditioner may be stuck on heating mode. If its a reverse cycle, the reversing valve may be jammed so even when the thermostat is calling for cold air, it stays on heat. If the machine is on heating mode, it should be blowing cold air out of the outdoor unit of the air con. If its on cooling mode, the outdoor should be blowing hot air.

A nice radiator and heater core flush should fix you up.

Please go to the link and check graph "2.5 Installing the Batteries". Its really easy so it should be a piece of cake.https://customer.honeywell.com/resources/techlit/TechLitDocuments/69-0000s/69-1800.pdf

Check the limits on the furnace.

This model has a rear heat/cold blend door actuator. Its an electric motor that moves the duct door from hot to cold. When they wear out, they're usually stuck on the last setting

When I turn on the heat in my 2004 mazda mpv the front air vents blow heat but the rear air vents are blowing cold. I have adjusted every setting is there something I am overlooking.

the colors of old system are for heat pump.if you have a heat pump you need heat pump thurmostat and colrs will make more sense.if not,then you need to go into furnace to see what colors go where.yellow is cool, goes to compressor contactor,usually another wire going from furnace to outside unit.green is fan relay rh is heat call rc is cool call

for now, put switches on thermostat to hear and press the up arrow button to the desired temp. All your programed temps will take more explaining and it would be best you secure a owners instruction book from home depot. oif anything, buy thr same thermostat and either keep it or return it . I'd keep it regardless, read the pmphlet,program you heat and a/c before returning for refund. Don't destroy packaging and give them back everything. You will also need two AAbatteries. Good luck.

Here is a link to a PDF of the install and operating manual


http://www.silverbowproperties.com/instructions/honeywell-RTH230B.pdf