AC/Heat question

[dottieshusband]

Well, it's that time of year.. starting to get into the 50's. I was checking to make sure all my cruiseair's were making heat. I have a couple that don't want to cooperate! (1987 63MY) They make AC fine. The thermostats are old Honeywell units, and there is NOT a place to swap from AC to heat, just Auto, Off, and Fan. There are two temp verniers, but the dial on top of the thermostat only moves the top vernier (I assume the bottom one is actual temp). On the units that make heat, I just move the dial that moves the top pointer up the scale into the 80's, and I get heat. On a couple, I get AC no matter what the setting..bad thermostat? advice appreciated..

[Canuck Dennis]

Get as close as possible to the 'stat, hear if it clicks when going up the scale or down, depending on room temp. if no click, possible faulty stat. if click, check to see if there is a reversing valve on the compressor unit, if there is, the solenoid that actuates the rev. vlv, may be defective, some suggest a quick tap with a blunt instrument to awaken the valve, but not recommended.

[eze2bme]

Also check freon level - low freon can cause no heat but fine cooling.

[dottieshusband]

Swapped the thermostat for a good one, no joy. Tapped on the reversing valve/solenoid with no luck. This really shouldn't surprise me as the heat has probably never been used. The unit is a 24k btu, and might be original. What do you think, repair, or replace?

[SeaEric]

Get someone to look at it. It may be something simple - like that it's perhaps a cooling only unit?

[Canuck Dennis]

Call a tech. if cooling, the 'pressor should be ok..sounds like a bad rev. valve. suggest you get the tech to bring one just in case.