Loosing faith in my Webasto

[Nam600]

It seems my issue is still not fixed as the heater failed again today with flame out first and then failed start errors H03 and H02 respectively. The flame out made me wonder if there was a fuel starvation problem. When this problem first started I had just over half a tank of diesel and the webasto takes its fuel from that. After a few trips there was just over 1/4 tank in the van today when the heater stopped working after 20mins and couldn't restart. I just put 30 litres in and now have 3/4 tank of diesel. Just tried the heater 5 times over 2 hours total run time tonight and it works perfectly. I'll try again in the morning to see if it still works.

Does this mean there has to be at least 3/4 of a tank of fuel to run it? Or is the heater standpipe too short or somehow not fitted correctly in the fuel tank?

 

[DXX]

Diesel fuel is being messed about with, their adding more Bio fuels apparantly which is affecting the start up time on Wallas hobs.

I was surprised to see the upper limit for bio-fuel in EN590 is 7%, I’ve not noticed any changes in my Wallas XC Duo operation over the years I’ve had it.
Back on topic to Webasto so we don’t loose track.

 

[oldiebut goodie]

From that description it does seem like there is a problem with supply. I would check out what has been done in the tank.

 

[Nam600]

Set the heater to start on a timer at 7.30 this morning and it worked again without issue.

I was looking at which type of standpipe they have fitted. If it's like the one below, then my guess is the bottom hose clip has not been tightened and the lower part has fell off into the tank. Would explain why the tank needs to be 3/4 full for it to work. I could not find any info on recommended minimum fuel level in the vans tank. Is there any word on that? I would guess 1/4 should be fine?

 

[oldiebut goodie]

That pipe should be one piece - I don't know why there is a rubber joint there.

 

[Nam600]

I just spoke with the installers and they say the used a t-in connection. I questioned this as I have read a few times that this can be a problem but they said this is an instruction by Webasto and comes as part of the kit. They say they have fitted loads of heaters like this and never had any problems. They are onto the Webasto UK Techs now so hopefully this gets solved.

 

[oldiebut goodie]

You can only tee into a pre-existing fuel line for a coolant heater not an engine feed or return line.

This will be your problem then. Either they have mis-interpreted the Webasto instructions or someone at Webasto is giving out wrong information. I know that Eberspacher give incorrect instructions and supply a kit for plumbing into the return line wrongly!

You cannot use an engine feed as it is pressurized and cannot use a return line as there is a non-return valve in the return line preventing the use of fuel from the vehicle tank.

 

[Nam600]

I've just seen that in the instructions you sent and was just about to ask that. My van never had the auxy/night heater as standard so I guess they installed it into the engine fuel return. I'm dialling their number right now. Thanks for your help with this; much appreciated!

 

[Nam600]

I've spoken with the installer who said that Webasto UK say it is fine to t-into the engine fuel return. He also said they had done loads like this and never had an issue. I explained it's only OK to do that when there is a 2nd fuel feed line for the parking/auxiliary heaters installed but that you cannot do it on the engine fuel return due to an NRV in the line. I sent him the pages from the Webasto installation manual which clearly states you must use a standpipe for fuel pumps without auxy/parking heater fuel line. He keeps coming back to the point that they have never had an issue before and to be fair, that is a valid point but the fact is the Webasto manual clearly shows using a standpipe and I clearly have an issue when there is less than 3/4 fuel in the tank.

He has agreed to install the standpipe so he's being very fair but I would still like to know why others did not have an issue whereas I do.

I think that the Webasto UK contact is giving out incorrect info and the manual confirms that. The moral of the story is to agree with the installer that they use the standpipe if you don't have the auxy/parking heater in you van.

 

[Nam600]

I've spoken with the installer who said that Webasto UK say it is fine to t-into the engine fuel return. He also said they had done loads like this and never had an issue. I explained it's only OK to do that when there is a 2nd fuel feed line for the parking/auxiliary heaters installed but that you cannot do it on the engine fuel return due to an NRV in the line. I sent him the pages from the Webasto installation manual which clearly states you must use a standpipe for fuel pumps without auxy/parking heater fuel line. He keeps coming back to the point that they have never had an issue before and to be fair, that is a valid point but the fact is the Webasto manual clearly shows using a standpipe and I clearly have an issue when there is less than 3/4 fuel in the tank.

He has agreed to install the standpipe so he's being very fair but I would still like to know why others did not have an issue whereas I do.

I think that the Webasto UK contact is giving out incorrect info and the manual confirms that. The moral of the story is to agree with the installer that they use the standpipe if you don't have the auxy/parking heater in you van.

For anyone else getting a diesel heater installed, I suggest you make a point of agreeing with the installer that they use a standpipe. AES took my van back and installed one FOC and the heater has worked fine ever since. Seems using the fuel return line from the engine does work but it stops after a couple hours use; presumably that's how long it takes to drain the return line. I found when that happened, I had to start the engine for a minute which refilled the return line. Anyway, fair play to AES as they did sort it.