Webasto will not fire up (burner)

[alt]

Again, trying to help a friend out here....

Webasto heater on his boat, was working fine until recently.

On the basic control knob, there is a Green LED which is now not lighting up.
When it's set to 'Fire', the relay in the control panel keeps clicking (is this normal?), the fan start up, the fuel pump starts clicking and I can see fuel going into the burner (infact, you can see heavy smoke from unburnt fuel coming out the exhaust). But then it shuts down. You can tell the burner isin't kicking in, there's no real noise from the unit, you know the kind it makes when it's burning away.

I don't even know what model this is, there was no ID on the unit.

I'm not sure if this unit locks itself out, but I don't think so, as it keeps cycling the above.

I checked the 2 fuses in pic 2, 7.5A and 15A - all good.

We set the thermostat to highest setting (we could hear the click) and by-passed it (by connecting the 2 wires)

Any ideas? I'm thinking wiring rather than a dead burner, given that the green light on the control knob isin't lighting up?

 

[simonfraser]

What’s the voltage at the heater unit when attempting to start up ?
Should be 12.0V at least else it is unlikely to start.

 

[alt]

What’s the voltage at the heater unit when attempting to start up ?
Should be 12.0V at least else it is unlikely to start.

This is always the no.1 thing I check - boat is on shore-power and batteries well up on charge. But thanks for the suggestion

I can't help but think there's a relationship with the green light on the control knob not lighting and the burner not kicking in.

 

[essexboy]

I note you say you have checked the voltage, but is that a look see ? or checked with a volt meter ? If you have a large resistance in the wiring whatever your putting in may not be reaching 12v + at the unit.

 

[alt]

I note you say you have checked the voltage, but is that a look see ? or checked with a volt meter ? If you have a large resistance in the wiring whatever your putting in may not be reaching 12v + at the unit.

Fair point, I was only assuming that power is OK as batteries are on shore power charger. I will check this tomorrow.

Would everything but the burner kick in if battery was not up to spec? IIRC my Eberspacher will not come to life at all if battery is not up to it (but I could be wrong on this!)

-EDIT- Also, I think the green light on the knob would still light up, even if batteries weren't up to knocking in the heater itself?

 

[ARE]

The combustion chamber can get carboned up around the burner and it’s gauze. This causes a lot of smoke, but no combustion. I would remove the heater and replace the burner assembly.

 

[simonfraser]

Just replaced the burner on my webasto hob. Not firing up.
Was full of ‘wax’, no way any useful amount of fuel would get through that.
Possibly could have just cleaned it out, but could not get it out of the burner without destroying it.

 

[alt]

Thanks for the info. Next challenge is what model is it? And where would one purchase a burner assembly online?

 

[ARE]

I got mine from eBay. Once you remove it, you my find the model sticker.

 

[simonfraser]

Sales@webasto.com
Mail them the pics, that’s what i did with my old hob, got the right burner £35 inc VAT PP etc.

 

[Mr Googler]

The control unit ref takes you to airtop 18, 24 or 32 if that helps

 

[alt]

The control unit ref takes you to airtop 18, 24 or 32 if that helps

Many thanks.

From Googling it appears to be an airtop 32. I see also that the model label is normally on top of the unit, which I didn't check the other day. So I guess next step is to confirm the model and while i'm at it may aswell take the unit out and disassemble.

 

[alt]

So I can confirm it's an Air Top 32.

Went today to try it again (changed fuses and re-made some connectors as they were dodgy) - now totally dead!

Can anyone recommend a Webasto shop to send it to? I'm in IRL so location not important, i'm going to have to remove and P&P it regardless.

 

[simonfraser]

See #10

 

[Riffler]

I have a Webasto Airtop 5000 and would not fire up. I did some basic checks and found the temperature sensor was incorrect. It showed the temp as 60 degrees and the heater was set at 40 degrees so it thought it was already up to the right temp and would not start. I then disconnected the sensor, tried a 4k7 resistor and then a 22k resistor and it all worked now. I then priced up a new one and it was £75??
i took the other one apart and inside was a NTC thermistor, I got one of those for 59P and it now all works fine, Just wonder why they charge £75 for a 59p item easily replaced with a soldering iron.

 

[lynallbel]

I have a Webasto Airtop 5000 and would not fire up. I did some basic checks and found the temperature sensor was incorrect. It showed the temp as 60 degrees and the heater was set at 40 degrees so it thought it was already up to the right temp and would not start. I then disconnected the sensor, tried a 4k7 resistor and then a 22k resistor and it all worked now. I then priced up a new one and it was £75??
i took the other one apart and inside was a NTC thermistor, I got one of those for 59P and it now all works fine, Just wonder why they charge £75 for a 59p item easily replaced with a soldering iron.

Because you are a clever sod and most people are afraid of electricity.

 

[Riffler]

From my experience I would check the external temperature sensor if you have a green light and it does not progress. Mine was showing the external temperature was 60 and the setting on the dial was 40 and therefore would not kick in. On easy way to check is to measure the resistance if you have a meter, it should be around 1k ohms, or if you have a spare 20k resistor put that in place of the sensor and see what happens then.

 

[Piers]

So I can confirm it's an Air Top 32.

Went today to try it again (changed fuses and re-made some connectors as they were dodgy) - now totally dead!

Can anyone recommend a Webasto shop to send it to? I'm in IRL so location not important, i'm going to have to remove and P&P it regardless.

The genius on Webasto is Toby Hague of Keto. Call him - 07976 925 166 - You won't be disappointed.

 

[Riffler]

If anyone is interested, you can solve many problems with some kit I bought only last week.

1. You need to get one of these
https://www.amazon.co.uk/Adaptor-OB...TF8&qid=1540843439&sr=8-3&keywords=obd+to+kkl

2. And one of these
https://www.amazon.co.uk/Belldan-VA...=VAG+COM+KKL+OBD2+USB+Cable+FTDI+FT232RL+Chip

3. Download this
https://disco3.co.uk/dl/pc_diag_2_14.exe

all this for less than £20 and once you have it you can find faults and share with mates problems and monitor your heater for correct operation.
There is a lead from the webasto for the K and L line and that is what you will be looking at to feed into the program above.
there is a diagram I have if anyone wants it. but it is really easy, touble is it takes a little time to come from China. But worth the wait

 

[Phildorset]

The genius on Webasto is Toby Hague of Keto. Call him - 07976 925 166 - You won't be disappointed.

That's nice to read - I have just this morning confirmed for them to install a twin Airtop system to Stella