Late Chim Heater fan speed.

[NeoVR]

I have a Chim which has the later style “variable” heater fan… except it doesn’t seem to be variable and just stays full speed when it’s turned on.
To be honest, I couldnt say when it changed, or if it ever worked properly..
Any ideas what the issue might be? - I’ve found threads about the control unit burning out but not one with this failure type.

[Dr Mike Oxgreen]

I believe the later ones have an electronic controller that varies the fan speed using pulse width modulation, so I’d say it’s likely to be that board has failed.

[over_the_hill]

Just an outside chance. Check if the twiddly knob has come loose. It locks onto the spindle with a grub screw (I think).
If it has, you could be twiddling your knob (oohh err mrs) without actually turning the spindle.