There isn't an override on the PR S1 for the hot plate. It does "LIMIT" the temp in the water chamber, but it isn't striving to keep you "at room temp"; it tries to stop “rainout” in the tube. There is not much to this control, but I wish they had an option that would allow it to adjust if you are using insolated/ lined tubes which is a standard fix for rainout.
The new Res Med S9, when you look at temp control, basically has this as a default in a convoluted kind of way. It still monitors the room temp and adjusts the water chamber temperature, but thru a thermocouple at the MASK END of the tube and not at the machine inlet. It also has a factory heated tube, so they might say not to wrap it with anything.
Side by side, the PR S1 against the S9 (with this option), the S9 would be able to produce warmer air more humidified air at the mask end. Basically, the S9 rocks; and even though I just got a PR S1, I still want one!
Retitrated 2/10 to 10cmH2O
Respironics SystemOne, FlexFit 407
Wife & I became hoseheads 30 days apart
I also got a "I TOLD YOU SO" nine years in the making.