Air con/Heater control. Honda CR-V

[Justin Passing]

2006 model.
There's a switch for air con, and then just a knob with temperatures.
Air con cools OK.
Heater calibration has drifted way off, it needs to be set to about 25 degrees to get warm at all (even when weather is cold, it's not due to the current weather).
I used to be able to set the temp to say 20 in this hot weather, with a/c on, and get "pleasant air", but now I have to set it much higher, again about 25.

I don't know how the controlling works, I assume the cooling turns down, rather than balancing heater air, but have no info.

I don't know what acts as a "thermostat" for the heating. Is it temp sensors and circuit boards, or bimetallic strips, or what?

I do hear the air con motor click on and off.

Not sure what it could be. Is it something a plugged in car analyser thing would help with?
Ta.

 

[Belle427]

Dealer level diagnostic equipment is the only thing that would get into that system to look for faults.
Is it climate control?

 

[ChrisR]

Is it climate control?

TBH I'm not sure exactly what the terms mean or whether it does what I think that means. The a/c reacts to the car temperature. Turn the temp up, & the a/c cuts out.
The knob has ~ 17 to 28 marked on it rather than low-hi so I assume it senses for the heater too.

My usual mechanic chappie has a Snap-On bit o' kit to do diagnostics. Are you saying those wouldn't go deep enough?

 

[Belle427]

I think it may be climate if you can set the temperature, usually there will be a uv sensor maybe on the dash and a temperature sensor on the control panel.
The snap on may be able to access the system if it has the correct software installed