Webasto controller upgrade

[Nigel W]

Can you please help a confused novice?

currently I have the basic rheostat controller as pic below and to get a more stable temperature I though about buying one of the new ones as per second pic.

however there would appear to be several versions and I don’t know which one is correct. One is called ‘car’ and has a very basic timer function (which would be fine for me) and the other which looks identical has a code ending in ‘E’ and is not much more money but seems much more sophisticated and I don’t need all those timers.

I have had a look at my loom behind the rheostat and I can see another plug which says ‘diagnostic’ and I gather this is the one to use - so is it just plug and play?

any help and advice gratefully received.

 

[Super-G]

Following this, as was considering doing the same to mine (currently have the basic rheostat)

 

[oldiebut goodie]

Always state which heater you have - controllers differ between models.
Assuming 2000STC:
If you have the spare plug with a red, brown and yellow wire that is the correct one. Remove the rheostat when using it.
As to which one to get - its a minefield!

Webasto Air Heater MultiControl Timer 9030025B is the one for a STC don't use the car - this is for water heaters. The letter after the model number is just the latest issue. ​

9030910E has now replaced the 9030025B so either of these as available are suitable.​

 

[oldiebut goodie]

"currently I have the basic rheostat controller as pic below and to get a more stable temperature"

To get a stable temperature the rheostat is perfectly adequate but you do need an external temperature sensor at mid height in your van.

 

[Nigel W]

Dear @oldiebut goodie thankyou for your help, much appreciated.
The ‘Car’ one I mentioned is the one below and it seems a bit of a bargain although I will probably take your advice and get the ‘E’ as it’s the latest.
regarding the temp sensor can you give me the code please and where does it plug in?
as you say it’s all a bit of a minefield!

 

[oldiebut goodie]

The "Car" one is for water heaters - Thermo Top Evo, Thermo Top Z/E/C water heaters so cannot be used. Sometimes they will work with other heaters but their software is tailored for the listed heaters only.

EVO AirTop Button Type Ext Temp Sensor 2.5m 9028864A external temp sensor - it goes into the loom here near the rheostat wiring. The resistor is cut out and the 2 blue/black wires are connected to the external sensor plug provided. 5m lead available - 9030883A
I can do a 2.5m one for £20, don't have any 5m ones left at present.

 

[Nigel W]

Thanks yet again.
the heater is under the drivers seat and the rheostat is right at the back of the camper in a panel so the loom runs behind all the built in units and is basically inaccessible.
tempting as it is to start pulling everything apart I think I will give the sensor a miss and now I understand that the controller is not really a thermostat either probably best I save myself the money and leave as is.
your a star and you help much appreciated.