Webasto Diesel strong smell

[rivonia]

Hi Folks.

We have had our webasto repaired. New buner unit/sensor and new circuit board. Well it eventually worked but it stinks of diesel while blowing out lovely hot air.

Why is that?

Peter

 

[pvb]

I'd guess it's been incorrectly repaired. It should have been bench-tested before being returned to you, and any undue smell should have been noted.

 

[rivonia]

Hmm unfortunately I'm out in the Med and it was repaired in UK. Taken there and back by a fellow yachtie.

Peter

 

[Ripster]

Is the smell coming in the cabin with the hot air or is local to the unit or from the exhaust? Is it burnt diesel or fresh fuel smell? We have had two webasto's and neither has smelled of diesel except occasionally if you catch the exh smell at startup.

 

[Ex-SolentBoy]

Is the smell coming in the cabin with the hot air or is local to the unit or from the exhaust? Is it burnt diesel or fresh fuel smell? We have had two webasto's and neither has smelled of diesel except occasionally if you catch the exh smell at startup.

Similar experience. I suggest you run it absolutely flat out for an hour, let it cool off for an hour and then try again. If the hot air still smells it is faulty.

 

[sailorman]

it may have got the exhaust flooded if it failed to fire up prior to repair, its also possible you have a split exhaust hose due to moving it to remove / re install the heater & the insulation could hold fuel as well.
did you seal the exhaust joint with hi temp silicone

Hi Folks.

We have had our webasto repaired. New buner unit/sensor and new circuit board. Well it eventually worked but it stinks of diesel while blowing out lovely hot air.

Why is that?

Peter

 

[Mistroma]

The fuel is burnt inside the combustion chamber and air passes over fins on the outside of the chamber. The heated air wouldn't become contaminated with diesel even if combustion was incomplete.

Exhaust gas could be pulled back in through the fresh air inlet buat that wouldn't change just because it had been repaired. I suppose that there could be damage to the gasket sealing the chamber or the chamber might have developed some pin-holes if fairly old. However, I can't say if the symptoms would include a diesel smell. Or diesel is wicking through the sealing gasket, perhaps someone else can confirm.

I did once have a strong smell of diesel from our old Eber D3L. I ran it without the ducting and the locker became very hot but no smell of diesel. So I checked the ducting anad found that a fuel line had been dripping some diesel on to it. The leak was tiny but the dreadful paper lined duct had sucked it inside. We got a distinct diesel smell when it was running and it was fine after it was replaced with decent (& cheaper) ducting. The CO2 alarm never alarmed so we were happy that it was safe enough even when slight smell. Do you have a CO2 alarm?

 

[David2452]

It is clearly recirculating the smell from the install site, unlikely to be an internal fault unless you mean diesel fumes rather than raw diesel smell. Its not diesel in the exhaust as there would be clouds of white smoke as it flashed off with the exhaust heat, not a diesel contaminated exhaust insulating sock as there would be clouds of white smoke in the install site. Does the install site have a duct from outside to the heater air intake? if not it should, It probably took a while to start not because of any fault but because it needed the fuel bled through, very common unless you use either thermo top software or a pump pulse device to bleed it first. I assume from your description of what was replaced that its an AT200s, I have never known a heat exchanger become porus on one of those but even if it was, again it would be exhaust fumes rather than a raw diesel smell. Webasto PEK duct is aluminium so unlikely that fuel drips would penetrate.

 

[oldfatgit]

With my Mikuni, after changing the glow plug, I had failed to tighten it enough. Result was that fuel wicked out of the combustion chamber and vaporised on the external hot surface causing unburned diesel fumes to enter the cabin. So, my suggestion is that you check the "repair" by taking the heater out and nipping up any and all joints which might link the combustion chamber but particularly the glowplug. Once you are happy, re-install and then run hot for about an hour to remove any condensed diesel from the pipework.

Good luck.

 

[rivonia]

Well thank you all for the input. I shall be trying it out at a later time and will be checking all the suggested systems that everyone has mentioned. I will get back to you to let everyone know the outcome.

Many thanks

Peter

 

[rivonia]

Hello All,

Well I said I would report back.... I stripped it again and found the fault. The exhaust tube was NOT fitted tight enough or far enough onto the exhaust. This meant that some exhaust fumes were creeping into the air and being sucked into the system. I refitted it all and ran it after a while the smell was gone-Hooray. Will be running it tonight for at least an hour.

Thank you all for the help/advice.

Peter

 

[sailorman]

high temp silicone will securely seal it, try ebay

Hello All,

Well I said I would report back.... I stripped it again and found the fault. The exhaust tube was NOT fitted tight enough or far enough onto the exhaust. This meant that some exhaust fumes were creeping into the air and being sucked into the system. I refitted it all and ran it after a while the smell was gone-Hooray. Will be running it tonight for at least an hour.

Thank you all for the help/advice.

Peter

 

[David2452]

Great that you found out what was causing it, but now it is clear that the install is sub standard it needs to be corrected, you should not have the heated air being drawn from the area the exhaust is sited in, I would advise a vent from outside the area with trunking leading to it, properly sealed.

 

[rivonia]

Great that you found out what was causing it, but now it is clear that the install is sub standard it needs to be corrected, you should not have the heated air being drawn from the area the exhaust is sited in, I would advise a vent from outside the area with trunking leading to it, properly sealed.

Yup did that as well-forgot to mention it. Thanks for the prompt.

Peter

 

[AD 2]

I did once have a strong smell of diesel from our old Eber D3L. I ran it without the ducting and the locker became very hot but no smell of diesel. So I checked the ducting anad found that a fuel line had been dripping some diesel on to it. The leak was tiny but the dreadful paper lined duct had sucked it inside. We got a distinct diesel smell when it was running and it was fine after it was replaced with decent (& cheaper) ducting. The CO2 alarm never alarmed so we were happy that it was safe enough even when slight smell. Do you have a CO2 alarm?

Hi Mistroma, we are just installing a Webasto 3500, and are a bit concerned about the dreadful paper lined ducting. What was the ducting you replaced yours with?

Thanks!

hey, whereabouts in Galicia are you? I spent a year in Santiago back in the day, and fell in love with the region.

 

[David2452]

Hi Mistroma, we are just installing a Webasto 3500, and are a bit concerned about the dreadful paper lined ducting. What was the ducting you replaced yours with?

Thanks!

hey, whereabouts in Galicia are you? I spent a year in Santiago back in the day, and fell in love with the region.

Webastos don't come with paper lined ducting, if you are in UK you can get really heavy spiral wound ali trunking for about £4 per metre.

 

[AD 2]

Webastos don't come with paper lined ducting, if you are in UK you can get really heavy spiral wound ali trunking for about £4 per metre.

I am in Canada, and the Webasto 3500 I picked up a little while ago definitely has paper lined ducting. Was just wondering what Mistroma might have used instead. Wouldn't there be a corrosion issue with using aluminium in a marine environment?

 

[David2452]

I am in Canada, and the Webasto 3500 I picked up a little while ago definitely has paper lined ducting. Was just wondering what Mistroma might have used instead. Wouldn't there be a corrosion issue with using aluminium in a marine environment?

Never had an issue with corrosion, the stuff is mostly in protected areas, I suggest you try to find a HVAC company local to you as they should be able to supply you with some heavy hob extractor duct, 80mm is their usual minimum size and that happily coresponds to the ideal size for an AT3500.

 

[timmygobang]

I am in Canada, and the Webasto 3500 I picked up a little while ago definitely has paper lined ducting. Was just wondering what Mistroma might have used instead. Wouldn't there be a corrosion issue with using aluminium in a marine environment?

This is very hazy but I've just had a webasto installed and from memory the guy said it had to be run for an hour after installation to burn away what I presume is the paper inner lining you're referring to.

 

[David2452]

This is very hazy but I've just had a webasto installed and from memory the guy said it had to be run for an hour after installation to burn away what I presume is the paper inner lining you're referring to.

Not if he used Webasto ducting, as I said earelier it does not have a paper lining, it is ali, I assume the reason it was run for an hour is to test all was well and then set the CO2 content of the exhaust using his exhaust gas anyliser.