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Discussion Starter · #1 ·
My van appears to have both the Thermo Top and Airtop Webasto heaters:



I know that the Thermo Top is a coolant heater and the Airtop a warm air heater.

There are controls on the overhead panel which I have never seen on another van:



There is a button for heat which when pressed will fire up a fan and blow hot air through vents in the pillar behind the drivers seat. I believe this is the Airtop working?

Then there is a button for a timer which let's me set up a start time, running duration and temperature level. I've tried this out and it also fires up a fan and blows hot air out of vents behind the drivers seat. Presumably that's the Airtop again.

The overhead panel also has settings for a remote control that allow me to set a duration and temperature level.



I didn't have a remote but managed to snap one up on eBay. It doesn't work so guess it needs synching. Anyone know how to sync it?

Question is, how do I control the Thermo Top? Is that what the remote is for? So I can't turn the warm air heater on using the remote?

Is there any way of adding a control panel for the Airtop to the back of the van? It's a camper so it would be nice to not have to lean across the front seats to turn the heater on.

I'm not fussed about having a coolant heater but I really want warm water to the sink. Is there any way of converting the Thermo Top to a water heater? Or a water heater that could be easily fitted in place of the Thermo Top?

I suppose the heaters are controlled through VW canbus so there's no way to get in to it?
 

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If the thermo top was factory installed it will come on automatically when you start the van and the ambient temp is below 11 degrees. You should see a small exhaust coming out of the skid panels below the passenger seat they are notoriously troublesome
 

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Have you got your owner's manual? Full instructions on how this panel operates are shown in there (Page 320 in mine). If you haven't, let me know and I'll scan the relevant pages for you.

The panel controls both the auxiliary heater (Webasto Air Top) and the auxiliary coolant heater (Webasto Thermo Top C).
 

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Discussion Starter · #4 ·
If the thermo top was factory installed it will come on automatically when you start the van and the ambient temp is below 11 degrees. You should see a small exhaust coming out of the skid panels below the passenger seat they are notoriously troublesome
Oh I see. I had noticed exhaust fumes coming from there and if I stop the engine a few minutes after starting it on a cold morning I can hear the sound of something running. I just thought there would be some control over it.

Have you got your owner's manual? Full instructions on how this panel operates are shown in there (Page 320 in mine). If you haven't, let me know and I'll scan the relevant pages for you.

The panel controls both the auxiliary heater (Webasto Air Top) and the auxiliary coolant heater (Webasto Thermo Top C).
Yeah, I've got a manual but when you read it the instructions for both heaters are basically the same. It doesn't explain how to turn on one or the other.

I think the way it works then is that if a van has both fitted the panel controls the Air Top and the thermo Top is automatic - no controls. If you have only one of the two, the panel controls it. So if you have only the Thermo Top you can control it?

Anyone know how to sync the remote? I tried removing the fuse for the heaters and holding the button on the remote when I plug it back in (instructions I read on here somewhere) but it didn't work. From what I've gathered the Air Top is controlled through the VW Canbus so I need to sync the remote with the car not the heater.
 

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I don't think the Thermotop is controllable in any way, I assume it is for speeding up the engine warm-up in cold weather thus improving the fuel consumption etc.

Rod
 

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I don't think the Thermotop is controllable in any way, I assume it is for speeding up the engine warm-up in cold weather thus improving the fuel consumption etc.

Rod
This was my understanding. However they can be upgraded with a kit to make them manually controllable (as well as automatic) you can even get a teletext kit T: planning on getting one for mine once I get the bloody thing working.
 

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Anyone know how to sync the remote? I tried removing the fuse for the heaters and holding the button on the remote when I plug it back in (instructions I read on here somewhere) but it didn't work. From what I've gathered the Air Top is controlled through the VW Canbus so I need to sync the remote with the car not the heater.
Do you have a remote that looks like this?



I discovered there are two versions of the remote which look identical. One is for the factory fitted auxiliary coolant heater (VW badged Webasto T91) and has VW part number 7N0 963 511. The other is for an after market fit Webasto T91. This remote has the Webasto part no 9014542A. Neither is compatible with the other.

The way to tell them apart is by observing what happens when you press the ON button. The VW part will display a GREEN led. The Webasto part will display a RED led.

How do I know? I mistakenly bought a VW remote for my aftermarket T91 :-(

The pairing procedure for the after market T91 is to remove the fuse for 5 seconds. Replace fuse, then after 2 seconds but before 6 seconds, press and hold the OFF button on the remote for a least 1 second. The procedure may be the same for the VW T91.

Which remote do you have?
 

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I believe that the the Thermotop can be adapted for interior heating but it will consume more from the vehicle battery as there is a water pump and heat exchanger (cab heater matrix) fan to run as well as the burner.

With a blown air unit (Webasto or Eberspacher) it can be powered from the leisure battery and only needs the burner/blower power.

I don't know about the efficiency comparison but would expect the water heater to be less efficient than the air version when used for cab heating as there is quite a bit of uninsulated plumbing involved.

Rod
 

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Discussion Starter · #9 ·
Do you have a remote that looks like this?
Which remote do you have?
One of these:



I saw it on eBay for a reasonable price so thought it was worth a punt. It looks the same as the one in the manual:



I've tried the disconnect/reconnect the fuse whilst pressing OFF but it doesn't work. I'm pretty sure that works for an after market Thermo Top with remote function but mine seems to be controlled by the vehicle. So I need to sync a remote with the van not the Thermo Top.
 

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Discussion Starter · #10 ·
Let's try that again.....


Do you have a remote that looks like this?

Which remote do you have?
One of these:



I saw it on eBay for a reasonable price so thought it was worth a punt. It looks the same as the one in the manual:



I've tried the disconnect/reconnect the fuse whilst pressing OFF but it doesn't work. I'm pretty sure that works for an after market Thermo Top with remote function but mine seems to be controlled by the vehicle. So I need to sync a remote with the van not the Thermo Top.
 

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Discussion Starter · #11 ·
Part number printed on the remote's battery compartment is 300 963 511 A. I haven't managed to find any info online to confirm if this is the right one for me.
 

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Hello,

I just found this old post while searching for Webasto advice. I have the same factory fitted setup on my T5 Multivan with central mounted control panel above the windshield. I purchased it second hand and didn't get the original manuals. I'd really appreciate if someone could share a copy of the instructions. I've never managed to get it going!

Raz
 
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