Webasto says beware dirty red diesel

Remember my run-in with the Webasto diesel heating distributors at the IWA Festival a couple of months ago?   It was started off by reporting problems that certain people were having running and getting maintenance on their heating systems.  I asked them about a particular case and it went downhill from there.  

I was talking about this with a senior person in Webasto UK, and he agreed to investigate the problem.  Why were some/many people  reporting problems running diesel heaters?

He's reported back, and in essence, the blame falls on red diesel.   Or rather, its variable quality.  'Foreign elements' in variable-quality fuel - such as water, ash and even traces of engine oil - cause many of the problems.

Getting clean fuel will continue to be a problem, not least because red diesel is set to be the convention at boatyards for quite some time.  Most marine engines work well enough on rough-quality diesel, so the pressure's on the the heating system manufacturers.

Of course, diagnosis is not cure.   If you have a Webasto heater, what should you do?   I'd guess that you'll need to clean out your diesel tanks regularly - especially if the Webasto shares them with the engine.    You aren't going to find clean red diesel any time soon.

What about other types of diesel heater?  Do they also need cleaner fuel than your engine? Is it possible to fit a suitable filter/trap? 

Meantime, BK Marine is no longer a Webasto distributor, although you'd not guess that from the BK Marine website.   Anyway, below is the official Webasto statement. 

Heaters Operating in the Marine Market

Following a number of investigations into the fuel that is available in the marine market it was found that the quality being supplied under the guise of “red diesel” can vary extensively between suppliers.

On analysis of some of these fuels it has been identified that many contain foreign elements such as water, ash and even traces of engine oil, all of which will have a negative effect on any combustion process.

During combustion these elements will create an increase in the exhaust outlet emissions and will also produce increased waste products which are deposited on the internal parts. These components within a combustion heater are typically the burner assembly and heat exchanger.

These deposits start to accumulate on the vaporiser matting within the burner which reduces the effective operating area; this reduces the quality of combustion further which then results in more deposits being produced. The cycle continues until the heater is unable to operate. Excessive smoke will also be seen coming from the heaters exhaust outlet during any of the operating process. The heat transfer efficiency of the heater also declines over a period of time as the deposits start to coat the heat exchanger and acts as an insulator preventing the heat from transferring into the heating medium, e.g. water or air.

It should be noted that heaters operating on poor quality or contaminated fuel will increase the service intervals frequency required due to the build up of the exhaust deposits as described above.  [the Webasto statement originally says 'intervals', but I changed it to frequency because I think that's what they meant]

Comments

[Sue]

I have had a Webasto system for three years, had it serviced twice and had a total of 3 months out of it. Last time it cost me £277 and lasted three weeks. If I could find another system I would willingly chuck the Webasto in the cut!

[George]

All of these heaters are designed for the motor vehicle market and, as such, are unsuitable for boats using red diesel. It is grossly unfair of Webasto to try and claim that "red" is contaminated. It is a different product, especially with regard to sulphur content. If Webasto cannot design a product to serve the market they should stop trying to sell them.

[Andrew Denny]

David: I don't think Webasto are saying red diesel isn't suitable. I guess they are just saying expect to have to service the unit more often.

[David Roberts]

They may want to blame it on red diesel, but if they are selling them for boats, and bvoats run on red diesel, then are they really fit for purpose?

[Andy]

There may be some truth in what you are being told. On the other hand most of the early Rover 75 diesels were fitted with Webasto heaters which come on in winter if the temperature drops below 5degrees.

Guess what? An awful lot of these heaters no longer work. They can't blame poor quality red diesel for these failures

[Andrew Denny]

Martin: good point, well spotted. I've amended it, because I'm sure that's what they meant.

[Martin]

Ah hah, here's one for the pedants: in the final sentence don't they mean 'decrease' rather than 'increase'? :)