Disco 2 Webasto Fuel Burning Heater install

Hi all. Done a couple of thermo top C installs, the last one I did was to my Navara, which works well.

As half my heated screen is dead Ive decided to go for a fuel burning heater install, the thermo top C units are getting a bit long in the tooth now, and generally require an overhaul/decoke and gasket set, the Rover 75 ones also suffer component failure.

as a consequence, Ive decided to go with the Thermo Top V variant as fitted to the Disco 3 and later range rovers, these are available on ebay from £60- £90, with various part numbers, and exhaust configurations. Ive picked one up from a breakers on ebay, and asked them to leave the plugs on, with a length of wire tails.
the reason for this is whilst the wiring is on and stowed on the Disco 2, its stowed on one plug, and the thermo top V (and C for that matter ) has two sockets on it, one for power and one for the various control lines and fuel pump output.

my intention to control its switching, is firstly via the 12V signal supplied from the alternator via the ambient temp sensor when the engine is running and outside temp is less the 5 degrees . ( this may or may not be already fitted- to be investigated )

on the Navara I used a cheap Chinese RF plipper remote control with a latching output to provide a start signal, and Ill replicate this on the discovery.

I will produce a "how to " by way of contribution to this forum, but first a question.

Im assuming that some sort of provision has been made for the fuel pump to pick up fuel from the tank, as there is an in tank pump fitted. I have noticed on the top of the fuel pump assembly that there is a plastic blanked off nipple type thing, is it as simple as cutting the end off this, or do I need to tee into the low pressure pumped outlet from the tank ? or alternateively fit a separate pick up to the tank ?

Erm actually scrub that question

shiny disco ball said:

on the Navara I used a cheap Chinese RF plipper remote control with a latching output to provide a start signal, and Ill replicate this on the discovery.

I will produce a "how to " by way of contribution to this forum, but first a question.

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You are aware that the D3/4 RRS FBH is controlled by CAN signal from the CJB, so it's not easy to run it in anything other than the vehicle that's designed to control it.

Surely spending £75 excess for stone impact damage on the screen will cost less than fitting a FBH.

You will need the webasto oval timer to start the d3 heater.
As for the d2 tank nipple, yes you can cut it and fit your standpipe into it.

If you look on the d3/4 forum there is a whole section dedicated to the fbh.

lynall said:

You will need the webasto oval timer to start the d3 heater

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Yes I was forgetting the Oval timer.
It can't be controlled by those cheap Chinese remote controllers though.

Nodge68 said:

Yes I was forgetting the Oval timer.
It can't be controlled by those cheap Chinese remote controllers though.

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Its how I run the one on my D3 so I come out to a warm engine, means I can start engine, spray de-icer on screen and pretty much drive away.
Iirc there is one extra wire to add to one of the plugs on the fbh itself.

lynall said:

Its how I run the one on my D3 so I come out to a warm engine, means I can start engine, spray de-icer on screen and pretty much drive away.
Iirc there is one extra wire to add to one of the plugs on the fbh itself.

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I had a 3rd button controller for my FBH, but sold it when I sold my D3. It was good, but I never worked out how to power the heater blower at the same time, which would have warmed the vehicle nicely.

I did this very thing on my FL1, using a Chinese remote, and a bit of rewiring on the blower motor. This was brilliant, as it preheated the engine, and warmed the cabin at the same time.

Thanks for the info. I may yet stand to be corrected but as I understand it the later thermo top vevo is can bus controlled, the thermo top V has an input for 12v from the ambient temp sensor so it switches the unit on when less than 5 degrees and the engine is running. According to the webasto tgermo top V manual there is another pin that if grounded starts the unit- but lets see when its delivered

shiny disco ball said:

the thermo top V has an input for 12v from the ambient temp sensor

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There is no 12V output from the ambient temp sensor, that's a thermistor

This sensor is a bimetallic switch

I was referring to the one for the aircon sorry

sierrafery said:

I was referring to the one for the aircon sorry

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Soz, it was 8 lifetimes ago when I was buggering about with these heaters on Rover 75’s, I confused myself which isnt difficult nowadays

the black thermistor one was used on the Rovers for the dash display and the aircon, its slowly coming back to me now. Nearly bought one of thermistor ones

I'm gonna add my bit as iv recently built a few remote control units to activate the fbh on D3s.
First off the fbh on D3s are not canbus controlled they are w-bus controlled units and as such require a w-bus modual to switch them on.
These w-bus boards were until recently pretty cheap to buy I bought mine for about £40ish each from the guy on the bay that makes and sells them but since the weather changed and every one wants then there £260 each.

I'm on the D3 forum and a few of us have a thread going.

The good news is if you have a old thermo c top fbh you can just swop the circuit boards over and dump the w-bus board then your good to go.

I'm hopefully gonna install a fbh from a td6 to my L322 v8 petrol lpg, retro fit if the breaker comes back to me with all the bits I'm after.

Nodge68 said:

I had a 3rd button controller for my FBH, but sold it when I sold my D3. It was good, but I never worked out how to power the heater blower at the same time, which would have warmed the vehicle nicely.

I did this very thing on my FL1, using a Chinese remote, and a bit of rewiring on the blower motor. This was brilliant, as it preheated the engine, and warmed the cabin at the same time.

Click to expand...

Hi Nodge, did you have any luck looking for that chinese remote/ heater blower wiring diagram for my FL1? no worries if not I can see you've had a belly full with theFL2 & fiat g/box/clutch changes so at your leisure.. Sorry to the OP for butting in but reading this just reminded me.

biketeacherdave said:

I'm gonna add my bit as iv recently built a few remote control units to activate the fbh on D3s.
First off the fbh on D3s are not canbus controlled they are w-bus controlled units and as such require a w-bus modual to switch them on.
These w-bus boards were until recently pretty cheap to buy I bought mine for about £40ish each from the guy on the bay that makes and sells them but since the weather changed and every one wants then there £260 each.

I'm on the D3 forum and a few of us have a thread going.

The good news is if you have a old thermo c top fbh you can just swop the circuit boards over and dump the w-bus board then your good to go.

I'm hopefully gonna install a fbh from a td6 to my L322 v8 petrol lpg, retro fit if the breaker comes back to me with all the bits I'm after.

Click to expand...

I fitted a petrol d3 webasto heater to a merc v8.

Nodge68 said:

I had a 3rd button controller for my FBH, but sold it when I sold my D3. It was good, but I never worked out how to power the heater blower at the same time, which would have warmed the vehicle nicely.

I did this very thing on my FL1, using a Chinese remote, and a bit of rewiring on the blower motor. This was brilliant, as it preheated the engine, and warmed the cabin at the same time.

Click to expand...

I think I have worked out how to power up the internal heater motor via the fbh, but its not simple as the heater is powered by a pwm signal on the d3, I have the parts now all I need is the enthusiasm!
Earlier discos it was a simple wiring/relay trick and you were away.

Altox is to dear, and there are always threads about issues/non starts etc.

lynall said:

I think I have worked out how to power up the internal heater motor via the fbh,

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IMO that "feature" doesnt worth the hassle as long as you have heated seats and screens and it will drain the battery big time. The usefull thing is the timer or remote to turn on the FBH 15-20 minutes before you hop in the vehicle then the blower will instantly blow warm when you start the engine. That's how mine is and i'm pleased with it, i have the oval timer and i set it to start let's say at 6.10 when i know i'll leave to work at 6.30 ... and so on.

Andy Warren said:

Hi Nodge, did you have any luck looking for that chinese remote/ heater blower wiring diagram for my FL1? no worries if not I can see you've had a belly full with theFL2 & fiat g/box/clutch changes so at your leisure.. Sorry to the OP for butting in but reading this just reminded me.

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Sorry I forgot.
I'll dig out the wiring today.

sierrafery said:

IMO that "feature" doesnt worth the hassle as long as you have heated seats and screens and it will drain the battery big time.

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That's not what I found when I went from my D3 without the blower function, to my FL1 with blower function, now back to an FL2 without a FBH.

The Thermotop C has a fan control output, which only switches the heater fan on when the FBH chamber is above a set temperature, so doesn't waste battery energy blowing cold air into the cabin.

My FL1 was completely de-frosted/de-snowed and actually very warm inside, after just 20 minutes of FBH action, even when the heater fan was set at minimum speed, which uses just 1.5 Amps. Also because the engine is at 75°C (the Thermotop maximum temperature), it starts fast, without glow plugs, so any energy used to warm the vehicle, is pretty well offset by reduced energy required to start it.

This to me is well worth the extra effort.

I do actually miss the FBH preheat facility, as my FL2 doesn't have an FBH at all. Having heated seats, screens and PTC heater simply doesn't come close to a preheated car using the FBH.

sierrafery said:

IMO that "feature" doesnt worth the hassle as long as you have heated seats and screens and it will drain the battery big time. The usefull thing is the timer or remote to turn on the FBH 15-20 minutes before you hop in the vehicle then the blower will instantly blow warm when you start the engine. That's how mine is and i'm pleased with it, i have the oval timer and i set it to start let's say at 6.10 when i know i'll leave to work at 6.30 ... and so on.

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I am in two minds, battery drian could be an issue, but if running a pwm controller you can run the fan real slow, in fact just enough to move the air with minimal power drain.
I do run my oval timer for 30 mins on cold mornings, pretty much all year round.

lynall said:

I am in two minds, battery drian could be an issue, but if running a pwm controller you can run the fan real slow, in fact just enough to move the air with minimal power drain.
I do run my oval timer for 30 mins on cold mornings, pretty much all year round.

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You won't have an issue if the fan is running at slow speed. My FL1 never had a flat battery running the FBH + the fan on low, and the FL1 battery isn't anything like as large as that fitted to the D3. The blower fan on low speed will used very little current, like I said, my FL1 fan used 1.5A to run on minimum speed, which is nothing really, and is definitely worthwhile.