Lowest aux heater setting still too hot for sub-zero temps...

HugoFar · Jul 25, 2016

We've just been away in our Cali and had a couple of nights where the forecast outside temp was to be below 0 degC, (-2 and -5) so we planned to run aux heater all night. (NZ winter) Even with the heater set at 1, we found we over heated. There are 2 adults upstairs,and 2 children downstairs. My understanding is that somewhere in the Cali is an aux heater linked temperature sensor that tells the heater when to turn off,and on again. (as it does all night.) Set at 1, this temp seemed to be 24 degC, (measured at coat hook left side B-pillar head height) which is too hot to sleep in. (warmer downstairs and cooler up top). Does any one know if my assumption of a temp sensor is correct, and if it is, where is it? I realise that opening (more) windows will cool things down,but that can also let in a Polar breeze. Or,does the heater just run for a time,and then cycle through off and on.
Perhaps the Webasto Air Top 3500 ST has an adjustable setting that I could check??
BTW, I have done a Google search and found nothing so far that covers this particular issue. Thanks.

snowy55 · Jul 26, 2016

The air temperature is measured on the inlet to the heater there isn't a remote sensor or thermostat.

HugoFar · Jul 26, 2016

Does that mean that the air temp in the right side front door step where the air is taken from pretty much controls the heater temp threshold?

snowy55 · Jul 26, 2016

That's how it must work.

HugoFar · Jul 26, 2016

Snowy55, thanks for the reply. Seems we'll have to try and manage inside temps with windows. Can't imagine needing to use the higher settings for heat, unless it got to under -10degC. Which is unlikely for us with a 2 year old,an 8 year old and us. Seems a few other posters relating to the out put of the aux heater also mention the high temps and even furnace like environment. Better than freezing tho I guess.

HugoFar · Jul 26, 2016

I've just found and been reading up on the- http://www.youblisher.com/p/807437-Webasto-Air-Top-3500-Workshop-Manual/, page 44/51 or 901+ 904, and it seems it is possible to fit an external temp sensor in the van, to get a more accurate temp threshold. (+10 degC up to +40 degC) Possibly more fiddly than I'm keen to try, but a shame this sensor (see 9.1.2.1) wasn't fitted from new. Maybe it is on the T6?

CYCLOPATH · Jul 26, 2016

Hi Hugofar,
Don't forget the human body produces about 75 watts of heat at rest, so that is 300 watts at night for 4 of you, in a small area, that is insulated.

When we were in the Alps last winter, we found the heater to hot at night, even on lowest setting. So we turned it on when we got back in the afternoon,,,,I guess doors are opening and closing and ther van is cold.
We then turned it off at night, then back on in the morning....worked perfectly

NZCol · Jul 26, 2016

Hugh, it's probably your arse generating all the heat mate

HugoFar · Jul 26, 2016

Prob right Col. Skiing down south was pretty average but having a school holiday California cruise is always good. Best views of Mt Cook ever. 4 motion a must. Keeping warm not a prob...

NZCol · Jul 27, 2016

Fwiw even on 1 we can't have the heater running all night esp downstairs it gets too toasty. With the internal topper as well now it seems to be ok without it, even in a Scottish winter

rod_vw · Jul 30, 2016

It seems crazy that with all the technology fitted in a Cali the night heater is not thermostatically controlled from a sensor in the habitation area. Never the less it is the norm for many campers fitted with either a Webasto or Eberspacher (VW have fitted both).
Even our self-build has an Eberspacher Airtronic fitted with an 801 controller that regulates to a settable degree C temperature at the controller which in our case is on the wardrobe face accessible from the downstairs bed area. I didn't bother with remote control or a preset timer simply because we had no need for them but both are available.

Rod