Hi

Lots of questions there!

Firstly, is your rear heater manually controlled by a pair of rotary dials (below the main ventilation controls) in the the center of the dash? - if it is then it probably isn't air-con!

There is a modification to convert the heater (which will be a Webasto Thermo Top C underslung beneath the front passenger seat) - this can give you the option to use as a parking heater via the front vents only. The maximum heating time is currently 2hrs, this is also dependent of the type of controller option opted for (unfortunately it's the expensive one!!).

The up-grade currently offered by the 'auxiliary' heater manufacturer (Webasto) doesn't give the option of running the rear blower, however, this is something i'm looking into and will let it be known when i've figured it out! The problem being is the vehicle CANBUS system and if/how the rear blower is controled by it and then how to by-pass the electrickery!

I realise this may seem like a sketchy answer, but, without waffling on about auxiliary heaters and CAM/WBUS, as it's quite a complicated system/not easily to explained so please feel free to ask any questions and i'll do by best answer!

AndyT:

 

what does the modification involve? DIY or buying some kit? or both?
Ive disabled my rear blower anyway since installed a poptop -personally I think the rear blower might have served a purpose when there were 9 ppl in the van and it was used as an airport taxi - but not now as a campervan.

 

Hi
Webasto do an upgrade kit, this transforms your auxillary heater into a parking heater with a timer, the best I can get at the moment is 2hrs of heat from it. This via the front ventilation fans. I'm trying to figure how to get the rear blower working too, but, the heat to the blower unit is disabled via a valve in the engine bay. This recieves a signal from the CANBUS which is where I'm struggling, it's my intention to generate hot water off this circuit. - i'm a mech engineer and the more compliated electronics is a bit outside of my knowledge!

Also, if I can extend the heating time I was intending to use the rear blower too, but, same problem!

The heater up-grade is pretty straight forward, but, a bit fiddly as you have to dig in the dash and remove the fuel intercooler, a days work all in all! If you're up to speed with the CANBUS it can be a really good solution to camper heating and hot water. It is possible to do by using a dedicated TTC with an additional blower, but, this takes space, I want to save space! Plus the cost!!

Andy:ILU:

 

any idea what they charge for the u/g kit? my shuttle is 2006 and not canbus (implemented with T5.5 I believe) so I can get at the guts using vag com.
why do you have to remove the fuel intercooler?
is there a seconday heater martix at the rear blower and the hot water valve to this is disabled? why not replace it with your own valve?

 

The heater upgrade kit is arond £270 + VAT + either a timer or telestart controller (not got the figures to hand!). I've just fitted one to a 55plate. And it does work well via the screen vents! I reckon I can source a cheaper one!

The rear blower has a built in heat exchanger which is served from the van cooling circuit.

You have move the intercooler to get to the TTC plugs, so it's not a drain down, you just have to move it out ther way! The rear heating circuit is initiated when the van is running and controlled via a 3 way control valve at the engine (ref.N279), I'd like to know how activate / control this!

If you know how to operate this valve it will work.

The heating time is set to max 2hr to prevent battery drain, but, the upgrade harness can be modified to be fed from the LB, hence not a problem!

Andy

 

sorry, whats a ttc plug?
do you think the parts in the kit could be replicated for cheap or is there a new PCB to install?
why not do a heart bypasss on the vw valve by using your own inline in front of it?

 

Sorry that's ThermoTop C! You have to insert a new cable, which comes which gives it a singal to run!

Anyone with a good electrical knowlelge should be able to reproduce the harness, but, for me -- I would have to buy one and strip it down completely, there are resistors hidden away which you have to find!

By-passing is another option I'm looking at,

 

Hi Andy

Thanks for your input, in answer to yours, the controls for the rear heater/blower are in the middle panel above the middle seats.

So the webasto upgrade is a seperate heater unit, and nothing to do with the rear heater?

What is the point of the rear unit? Is it just hot engine air and cool outside air? Or is it aircon if I have controls in the roof?

Thanks

Vince.

 

I work for an audio/electrical company and my boss is pretty switched on with auto electrical.

So are you saying we can use the auxilary heater as a camping heater if we get the electrics right?

 

ive got a shuttle with a/c and controls in roof. Actually I should say, I HAD one, i removed roof to make poptop . there are ducts in roof liner from rear blower. It doesnt connect to front air source at all. So no a/c from rear vents.

 

Hi Vince
the rear hearter is a blower box with a built in water heat-exchanger, it's heat source is the engine coolant circuit, this topped up via a Webasto Thermo Top C beneath the front passenger seat, in essence it is a stand alone heater, but, it works in conjunction with the engine. it receives a signal to say run, it then self regulates until it's told to switch off, the van diagnostics just reads it's status (on/off/fault). This is known a supplementary heater (as it supplements the van heating!)

There is another version known as a parking heater, this is used to keep the engine fro freezing (kicks in at round 6deg.C), this can be used in winter to defrost windows and have the van up to temp. This also tops up the engine coolant temp while running.

We (scooby and I that is) are going on about upgrading the supplementary to a parking heater.... I'm working on making it a full blown cmping heaterf with a hot water system too, so yes is the simple answer and the electrical control's where i'm struggling!

The rear blowers also have an air con option, this is a secondary cooling system too.

Andy:ILU:

 

I stand corrected on the A/C.
if you crack the suplemtary > parking heater u/g let us know. I could do with a cheap camping heater (all I got now is a 750W electic oil filled heater for when I got a hookup.)

 

will do mate, if you fancy a nice air top 2000 i can help! got one on ebay just now (worth trying!!)
Check it out on eBay!

 

Hi Andy


So my supplementary heater can be upgraded to a parking heater with the webasto upgrade, correct?

Or did I misread that?

If the rear heater has its own heat exchanger under the passenger seat, is'nt just a case of rewiring/replumbing the heater to run independently from the engine?

Sorry if I sound lame )


Vince.

 

Not lame mate, you just misunderstood.

The heater under the passenger seat is a Diesel heater (Webasto THERMO TOP C), connected via pipes to your engine coolant circuit, the rear blower has a water radiator inside it - this is connected too but a different branch.

The diesel heater is the thing that can be up-graded to a parking heater... hope this makes sense?

Andy

 

Ok cool, so I have the bit under the passenger seat too, and with the webasto upgrade can run as a parking heater? And does'nt required the engine on? And its the electrical circuit that limits it to 2 hours?

What electrical questions do you have, and i'll put them in front of my boss tomorrow, worth asking T:

 

that's it!

The problem i am having is understand where the feeds go to and from, the way i understand it is the vehicle CANBUS gives a volt free signal (run/stop) to the ecu in the diesel heater, this limits the time to 60mins or 120mins dependant on which type of controller you opt for.

The other issue is the 3 port valve and have prevent that from closing so the heat can get to the back, the idea of a parking heater is to warm the engine and defrost the windows not heat the rear, which is what I (people want to do!).

cheers for now, got sign off!

Andy

 

Are those problems to do with the webasto upgrade you can buy?

From my experience with eberspachers, their control modules also limit time to 60 or 120 minutes, but I thought that was just to prevent overuse and burn out.


It begs the question, whats the actual point of having the big old blower in the rear )

 

Not 100% sure, as there are various scenarios....

the problem of time is more associated with the type of heater and how it has been installed. historically the 'wet' systems are parking heaters, and made for the continent where temperature are much lower, therefore, running at higher load, the maximum time is associated with running the vehicle battery down!

OEM heaters are generally controlled via the vehicle ECU as with VW, they receive a signal to run and signal to stop, this is time or temperature orientated.

I've fitted air blowers to utility vehicles where they are for frost protection of equipment and operate for long periods (not at full load though!). In campers or boats there are heaters with different ECU's for operating for longer periods too!

All the units heaters have overheat protection built!:*

As far as the rear blowers are concerned they are there to supplement the front heating, it's not powerful enough to heat the whole van in very cold weather.

Probably as clear as mud now!

 

Hi
after upgrading the VW supplementary heater to a parking, i've found the rear blower is supplied with a different circuit from the front (cooling circuit that is), you can get the blower to work idependantly, but, the hot water is from the the van coolant pump. this only runs with the engine running, it is possible to connect up using control valves, expansion loops, etc. the cost of parts is very high making it impractical.

I've gone for a webasto camper kit which is 'stand alone'. The kit includes an expansion/header tank, plate heat exchanger for hot water, fan unit, etc. This where the fun starts getting it to fit!

This isn't the end of it though, i'm determined to utilise the OEM heater and rear blower as i think it to be a good solution for a camper!:*

 

Hi Andy, been reading this with interest as I was thinking that I could connect a calorifier to the pipes coming out of the rear heater/blower and get hot water from it. I have the thermo top c fitted for heating from the diesel tank and thought that the pipes would be connected to this. If it isn't and there has to be a lot of jigerry pokery then it probably isn't worth the effort. I'm not clued up on how these units connect up so if you or anyone knows of a sensible work around i'd be pleased to know.

Geoff

 

Hi Andy

Just wondered if you ever got this going? I am thinking of doing something similar to get hot water in my camper but am not sure where/how to mount the heat exchanger.

Cheers
Mark

 

Any updates on this subject?
Andy did you manage to get the hot water?

I just got a Caravelle and found out it has the Webasto Thermo Top C fitted, same sticker as the others.
Need hot water! I Was thinking to install a 12V 6liter boiler with 220V transformer but if the TTC can be hacked that would be awsome..

 

sorry folks, i've not been on the ball with this!

I have just helped out with a system, I chopped the cooling pipework and extended it through a heat exchanger to give hot water while the van is running, this could be put through a calorifier type heat exchanger to give some hot water storage. there are also methods of running a supplementary heater while parked up 9this would do the same), the only issue is the heater will only run for an hour.

Auxillary heaters can be modified to give continual heat, but, this involves changing the ECU, Wiring Harness and Controller, the cost of which is £316.75, £93.37 & £101.56 ex. VAT eek for parts only, you would then need pipe and a suitable calorifier or heat exchanger. So it gets pretty expensive, but, it is an excellent system and saves quite a bit of internal space.

It is perfect when going down the gas free route!

Andy

 

Hi Andy, I have just send you an email.

- Why do you need the Webasto Termo Top C to make hot water?
Just have to cut the engine cooling and put a heat exchanger in there.
You could store that in a 12V boiler to keep it hot and connect to a water pressure system.

- What about the 6L Elgena boiler at 12/220V with an invertor?
So when the engine runs it can pull the amps necessary to heat 6 liters in about an hour.
Than 12V to keep it on temperature.

What are the advantages / disadvantages of these 2 systems?

 

The Thermo Top is already there! Space is always an issue with small vans. What you are suggesting seems fine to me, although I am not familiar with the boiler you mention.

Andy