Testing a new dehumidifire

The laundry mode is probably trying to get the RH to 0% (knob fully in the clockwise position) The same Humidistat Dial sets the RH setting to between 35% and 80%.

On my DD122 Simple, which I believe is the same model as yours, turning the Humidistat Dial switches the unit on/off almost instantly when the RH value indicated by the dial matches the RH of the room (give or take, say, 10 to 20%). I have a couple of cheap electronic Temperature/RH meters in my rooms which are not that accurate.

Perhaps leave it running overnight in a small room with the doors closed and check again in the morning to see if the Humidistat Dial controls on/off. The unit may take a short time to acclimatise.

The turbo switch doesn't change the behaviour of the Humidistat Dial

Is that with or without a couple of open pans of boiling water and extractor off? This time of year in a centrally heated house the RH can be pretty low. It's 40% here ATM but it's been unseasonally warm and wet recently.

Or the kitchen with a pan of boiling water and extractor off.

I've got one and it takes an exceptionally dry room to not trigger the stat until it's on max aka laundry.

You could put it outside or in the shed/garage for an hour, then see if the stat clicks at a lower setting (it is mechanical).

Thanks for the replies I have set it up at high (not laundry) next to a clothes horse of wet clothes and will see what its like in the morning, if that fails will try the shed.

I guess a steaming kettle nearby might trigger it. Most of these things have hysteresis, so they tend to have to go over the level and under the level to be triggered. Brian

yes. If it doesn't its toast.

NT