Webasto F-02 fault

[Littleblackflash]

I've a Webasto EVO 40 which I've fitted to my van under the drivers seat and blows air through the B-pillar vent.

It lights every time and will run for 2hours when using the quick start. Afterwards, it won't relight. I can try several times through the freezing night but it wont relight, and I get a F-02 Burner Failed to light code.
If I run the engine for a while, the Webasto heater will work again. I'm wondering if the fuel pot is running dry and therefore running out of fuel? The main fuel tank is 60% full.

My fuel pump is mounted on the passenger side, so that the fuel lines go up over the center tunnel to the heater and the other way it goes up to fuel tank top. I think the pump is higher than the heater, but parking on a slope at the weekend, the pump would of been below the heater level.

Any ideas? It was freezing in the van at the weekend.

 

[Dellmassive]

@oldiebut goodie

Any advice to offer?

 

[oldiebut goodie]

How is the fuel drawn from the tank? My 1st suspicion is that you have tapped into the fuel return line and it is draining all the fuel that it can get from that line.

 

[Littleblackflash]

I've using a the small stainless pipe going into the fuel tank sender as described in the manual, not in the return line.

The fuel pump is mounted next to the fuel tank where the Adblue tank would be. (Mine is Euro 5). The pump is mounted about 1/2 way up the fuel tank height, so the outlet from the fuel tank goes down to the pump, but I expect the pump to be above the bottom of the standpipe.

Where is the best place to mount the pump? Would it be better if I mounted it below the heater it's self?

 

[oldiebut goodie]

Fuel should not be a problem for re-starting then. Ignore that.

Only running for 2 hours sounds like you have a Multicontrol fitted and it is set with a 2 hour run time limit. What happens when it is set to infinity?

What voltage is the heater/Multicontrol set to stop at? after 2 hours running the battery most probably dropped its power enough that when you try to restart the current draw from the glow pin is bringing it down below the cutoff point, hence it working again when running the engine. If left running the current draw is less so the voltage drop isn't enough to shut it all down.

 

[Littleblackflash]

That makes some sense and gives me so ideas

Yes, I'm using the multicontol but I've never set the voltage stop limit? Where can I check this? I've not tried running it infinity but I guess at some point the heater would turn off when the van is the right temperature.

It's connected to a Renogy 100Ahr lithium battery that was fully charged. In the morning it was still showing 88% capacity. Without starting the engine, I was able to run a cement mixer through an inverter for several mixes, so I know the battery had power and 88% was a realistic measurement.

 

[oldiebut goodie]

The setting is cunningly concealed - you can only access it with a Webasto dongle and ver 3.6 + of WTT. The installer should have asked you what level you wanted it set at. I set them at 12v in absence of any preference to save running the battery down too low. You can set it as low as 10.5v by which time your battery is goosed!
If you have your external temp sensor at the correct height you shouldn't have your heater shut off - the idea is that the heater drops its output as the temp rises.

 

[oldiebut goodie]

Ideally you need to take a voltage reading as close to the heater as possible whilst it isn't starting to see what voltage it is seeing. I would do it with the computer then I could see the voltage drop as the glowpin energizes.

 

[Littleblackflash]

Rich - The heater was supplied by you but installed my me. Can I assume you set it to 12v?

 

[oldiebut goodie]

Yes, it would have been - I sell so many heaters that I lose track of them!
That brings us back to voltage drop that really needs to be checked/seen when it will not restart. In the absence of any other fault code this would be the first thing to check.
Did you check to see if there were any other fault codes?

Turn the control knob in order to choose the
desired “Error information” symbol.
Error
information
Settings
Press the control knob in order to confirm
selection.
Error message (-s) is (are) shown in the display.
If there is no error message then „OK.” appears in
the display. If there are more error messages then
all the messages can be displayed by turning the
control knob.
Settings
Press the control knob in order to return to
submenu.

 

[Littleblackflash]

So I had another weekend in the van and another without a working heater.

The battery voltage measured under the drivers seat connection which goes direct to the heater below the floor, never dropped below 13.4volts. I can't see there being any voltage drop in the short 30cm of cable to the heater.

This weekend's issue was different. I started the controller with infinite timer so I hoped it would stay on all night. The green light came on on the display and stayed on all night, but the heater never came on. The thermostat was set to 22degC and the display measured 5degC, so it should be demanding heat. I couldn't hear the fuel pump click or the heater trying to light, but the heater never came on and no fault codes displayed.

I'm confused.

 

[oldiebut goodie]

Have you checked to see if error codes are held by the Multicontroller as above? You should be able to see the last 5.

Disconnect the power for 30 seconds or more then reconnect and try it, it appears to have gone into lockout due to the errors. Ideally it needs the error codes read to see what other errors are logged.

 

[Littleblackflash]

The multi controller is not showing any faults. I don't have the extra lead to connect it to my computer so I can't see everything.

I'll try pulling the fuse, and waiting 30sec for it to reset.

 

[oldiebut goodie]

Both fuses.