Vito W447 2015 installing W Bus Webasto Thermo Top... I need engine plumbing advice

[AndyBristol]

Hi all newby here, I've had my Vito for around 3 yrs now and I have a Webasto Themo Top Water heater, its taken from a VW mpv and runs on W Bus, I already have an adaptor so I can start and stop the heater via a switch or timer. I'm looking to heat both the engine and cabin when the heater is on, IF anyone has installed one of these heaters into their Vito I would like to ask a few questions. Things like, do I need to use the Webasto water pump OR the MB one which I believe is fitted ?, the best place to connect the heater unit in the engine plumbing, I intend to fit an independent 5L fuel tank within the engine bay (room permitting) don't really want to have to drop the tank to get a fuel supply. With the weather getting colder and colder now (currently minus -5.6 deg outside as I type this) this would be the time to get this project off the ground, basically ANY help from anyone that knows these things, it would be gratefully received. I would also like some advice on how to best wire the heater motor and find out things like, when I shut the engine off, I hear the heater flaps moving, will I get any air out of the vents or does it default to the windscreen and so on... again any advice. IF anyone has any info such as engine plumbing layout wiring diagram etc... Thanks. I'm based in Bristol and disabled so it won't be an easy task for me to do this and may take me several weeks to complete.

 

[Larkone]

You would probably stand a better chance of finding someone with the knowledge you are seeking on the RV forums

 

[AndyBristol]

You would probably stand a better chance of finding someone with the knowledge you are seeking on the RV forums

Thank you great thought, will do so later on can't be doing it on a mobile lol

 

[ColP]

Hi all newby here, I've had my Vito for around 3 yrs now and I have a Webasto Themo Top Water heater, its taken from a VW mpv and runs on W Bus, I already have an adaptor so I can start and stop the heater via a switch or timer. I'm looking to heat both the engine and cabin when the heater is on, IF anyone has installed one of these heaters into their Vito I would like to ask a few questions. Things like, do I need to use the Webasto water pump OR the MB one which I believe is fitted ?, the best place to connect the heater unit in the engine plumbing, I intend to fit an independent 5L fuel tank within the engine bay (room permitting) don't really want to have to drop the tank to get a fuel supply. With the weather getting colder and colder now (currently minus -5.6 deg outside as I type this) this would be the time to get this project off the ground, basically ANY help from anyone that knows these things, it would be gratefully received. I would also like some advice on how to best wire the heater motor and find out things like, when I shut the engine off, I hear the heater flaps moving, will I get any air out of the vents or does it default to the windscreen and so on... again any advice. IF anyone has any info such as engine plumbing layout wiring diagram etc... Thanks. I'm based in Bristol and disabled so it won't be an easy task for me to do this and may take me several weeks to complete.

Hi, I’m about to do the same thing with an Eberspacher I’ve just bought.
I’ll update here with anything I find out.

 

[ColP]

Hi all newby here, I've had my Vito for around 3 yrs now and I have a Webasto Themo Top Water heater, its taken from a VW mpv and runs on W Bus, I already have an adaptor so I can start and stop the heater via a switch or timer. I'm looking to heat both the engine and cabin when the heater is on, IF anyone has installed one of these heaters into their Vito I would like to ask a few questions. Things like, do I need to use the Webasto water pump OR the MB one which I believe is fitted ?, the best place to connect the heater unit in the engine plumbing, I intend to fit an independent 5L fuel tank within the engine bay (room permitting) don't really want to have to drop the tank to get a fuel supply. With the weather getting colder and colder now (currently minus -5.6 deg outside as I type this) this would be the time to get this project off the ground, basically ANY help from anyone that knows these things, it would be gratefully received. I would also like some advice on how to best wire the heater motor and find out things like, when I shut the engine off, I hear the heater flaps moving, will I get any air out of the vents or does it default to the windscreen and so on... again any advice. IF anyone has any info such as engine plumbing layout wiring diagram etc... Thanks. I'm based in Bristol and disabled so it won't be an easy task for me to do this and may take me several weeks to complete.

Regarding the fuel supply to the heater, I’m looking at a T piece in the Vito fuel return pipe to the main tank.

The Eberspacher Hydronic installation doc might give you some ideas.

Eberspacher installation manual