Webasto

I'm planning on fitting a Webasto to my 200 TDI 110. It's the type that heats the coolant.

It's dual function will be to first to warm the engine, and then when it's up-to temp, clear the windows and take the edge off the cold in the cab via the blowers.

I will in the main be running it with the engine off, but there may be occaions where I run both at the same time.

I've bench tested the Webasto, so I'm happy that it works as expected. I'll be making my own loom for it, including my own controller which will control the heater on a time basis and via wifi.

I've decided the best position for it will be where the screenwash bottle is, so I'll be moving or replacing that. This allows easy plumbing to the heater matrix and engine.

My query is regarding fuel supply. Those that know the Webasto, will be aware that it has it's own little fuel pump.

There are 3 main options that I can see for fuel supply:.

1. New standpipe in fuel tank with dedicated line. I'm not planning on doing this as I understand it's not required on vehicles where the pump is not embedded in the tank and it seems a lot of work for little benefit.
2. Tee into the fuel supply line between the tank and the lift pump, running a short line to the Webasto. Would this require a check valve to prevent siphoning on the Webasto when the lift pump is running?
3. Connect a line for the Webasto to one of the unused ports on the fuel filter housing. I'm still using the housing from my 2.5 NA, so there is at least one free out port.

My preferred option is 3 as it will be the neatest but I'm worried that ,as this is post lift pump, that the pressure may be too much for the Webasto pump - Has anyone tried this?

I would appreciate peoples thoughts and experiences on this.

have you had this out of a rover 75 diesel? they have there own pump bolted to the unit

THEengineer said:

have you had this out of a rover 75 diesel? they have there own pump bolted to the unit

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No, this one was from a Mercedes A class. It's a Thermo Top Z. Basically they are very similar to the Top C. They can come with and without the pump, but mine was an aux heater so no water pump with it, but I've sourced one separately.

well in the wifes rover its a webasto that warms the cab up quick,they can even be programmed to work via remote so you could warm your cab without running the engine its on the water side has a pump on the water and one on the fuel can help with pics of its set up if that helps but cant take them until the week end

THEengineer said:

well in the wifes rover its a webasto that warms the cab up quick,they can even be programmed to work via remote so you could warm your cab without running the engine its on the water side has a pump on the water and one on the fuel can help with pics of its set up if that helps but cant take them until the week end

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I would be interested to know the fueling arrangements. I know exactly what I'm doing with all the other plumbing and I've found a fair few pics on the net.

As it stands, my engine is only just coming up to temp when I get to work and it's not even cold yet!

sp00k said:

I would be interested to know the fueling arrangements. I know exactly what I'm doing with all the other plumbing and I've found a fair few pics on the net.

As it stands, my engine is only just coming up to temp when I get to work and it's not even cold yet!

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know the 300tdi is similar to yours but that warms up very quick i will take piccies of the fuel set up on the weekend

Did some more research. The maximum fuel pressure at the tap off point for the dosing pump is .3 bar. I guess this rules out the fuel filter housing - I've no idea what pressure the lift pump supplies, but .3 bar seems very low, so I would imagine it's in excess of this.

i'm very interested in this as i'm contemplating one of these in my landrover but the possible problem for me is the controller (i'm not an electronics guru but have built odd electronics projects 30 or so years ago when i was tinkering with ham radio) and have been hunting and reading all over the web for clues to switching the thermotop on, i've found a wiring diagram or two that i've bookmarked but as far as i can see it's not a simple job of using a couple of manual switches to turn the thing on/off as it needs to go through a start up cycle and then a cool down cycle when switched off, this leads me to believe i need an external control board that actually tells the thermotop the procedure it needs to go through

i have the basic thermotop C/Z with waterpump but still need to find a dosing pump (minor problem)

any help/advice you could give would be appreciated, i would love to fit this in my 1965 200tdi'd 109 van, the intention will be to remove the centre squab and make a dummy up in conjuction with the toolbox under it that will house a large matrix and fans/ducting to try and get some warmth into the cab, my poor old round smiths just doesn't cut the mustard

Cheers
Pete

Hi Pete,

You can run the Webasto manually. The onboard controller board takes care of the startup and shutdown sequences. To run it manually, you just need to hold 12v or ground on a certain terminal. The terminal and if it's 12v or ground depend on the model.

In my case, it's 12v. When this is applied, the Webasto runs through the startup sequence which lasts about 2 mins, then moves onto normal running. At any point that I remove the 12v, the shutdown sequence begins immediately, which lasts about 1 min.

Along similar lines, there is also a 12v output which is raised when the coolant temp is warm to enable you to switch on the internal heater fan via a relay.

There are also project instructions around where people have bought and cannibalised a mains controllers to use as a timer project.

Sadly my Webasto is still on the workbench as I'm having flameout problems with it, but I've got a few things to try which will hopefully work, otherwise I'm looking at a new burner which is about £90.

Thanks for the prompt reply, hopefully over christmas i'll be tinkering and looking closer at wiring diagrams then if it's more or less that simple

Cheers
Pete