Help with webasco heater

[bccoast]

On route to vancouver bc in sub zero conditions and our diesel heater died last night. Model evo 5500

Light on control panel of heater goes on but nothing happens. No error code flashes. Maybe blew a fuse but cant find them.

Any help appreciated greatly.

2013 jeanneau sun odyssey 409

[bereboot]

Perhaps the fuel is frozen ?

[moe58]

Hello bccoast

I have the same Webasto heater on my 2017 SO389. The burner is very sensitive to fuel quality. It requires regular maintenance to keep it clean. It could be a problem with the burner. It could also be the dosage pump that supplies fuel to the burner. 

cheers

[bccoast]

I don’t think fuel is frozen as it was running and warm in the compartment area and while it was still warm in there couldn’t restart and there’s water that’s not frozen from condensation around

I called Marine service center and they said it could be the one app 15 or 20 amp fuse there are three of them somewhere in the aft cabins from batteries to the heaters. Just haven’t been able to find them. En route to a new Harbor now but will look tonight and in the morning. If anyone knows where those three fuses generally are, that would be awesome.

[Mistroma]

I see you are afloat, I wasn't certain when posting about your bowthruster. I had a problem with my Webasto soon after delivery in 2009, possibly early 2010 season. I found a slightly melted 15A or 20A blade fuse and think I replaced it with another which ran rather hot. I think I swapped it for next size and no problems afterwards.

I haven't used it in anger for many years but do cycle it on for 30 minutes every 6 weeks or so. I did it once when air temp outside was 40C and cut that run a bit short.

My fuse wasn't easy to find but it was in a locker under the berth in the aft cabin on port side, same side as the heater but about 2m from it. It could be anywhere but might be worth checking a similar location moderately close to the heater. It was in the middle of a load of wiring not far from the isolation switches.

Yours could be completely different as it isn't a 42DS but I think the general wiring will be similar around the isolators. Worth a quick check with a torch on the inside of a bulkhead near the isolators.

Perhaps someone with a 409 will appear and give the exact position.

Mine is the 5000 version and I have a wiring layout here (small yellow square is the 15A/20A fuse "Fusible chaudiere").
Webasto wiring 42DS


No idea about the other fuses, possibly one near the heater and another for the pump. You could try turning on the heating with thermostat on full and lie down in the aft cabin above the fuel tank. The pump should be pretty close to the tank and will make a regular clicking sound initially. However, it will stop after a short while if a problem is detected. At least it would indicate power is reaching the pump.

You could check the manual for flash codes if you are getting power. Just a matter of counting flashes and looking up the error code if that model has that feature (most do report errors via flashing LED).

I also vaguely remember something about the control unit locking out after the same error appears several times. Might be worth checking it that's correct before proceeding.

[NZL50505]

Dec 28, 2021 22:02:36 GMT bccoast said:

I don’t think fuel is frozen as it was running and warm in the compartment area and while it was still warm in there couldn’t restart and there’s water that’s not frozen from condensation around

I called Marine service center and they said it could be the one app 15 or 20 amp fuse there are three of them somewhere in the aft cabins from batteries to the heaters. Just haven’t been able to find them. En route to a new Harbor now but will look tonight and in the morning. If anyone knows where those three fuses generally are, that would be awesome.

My Webasto had a single 15A fuse close to the house battery it was connected to. This is because the heaters are often wired directly to the battery to prevent accidental sudden shutdown. So I would hope if you inspect all the wiring in close proximity to your house batteries you should find it. Mine had blown and so I also replaced it with next size up (20A) and no problems after that.

[bccoast]

You guys are amazing, beers on me. Found the fuse box with 1amp and 20amp fuses, tucked in the starboard side battery compartment but had to get my head all the way in there to see it. I replaced it with another 20amp and it fired up but blew after a couple minutes. I put another one in and so far so good. it is freaking cold in the back hull section where the heater is right now so maybe was drawing too much?



 

[NZL50505]

I contemplated increasing it to 25A and if the 20A had blown again I would have tried that. But I wouldn’t go above that.

[zaphod]

Up-sizing a fuse is never a good idea. The fuse is blowing for a reason. It could be a bad connection, an intermittent short circuit, or a failing component.

[Mistroma]

I'd agree with that normally. I checked all the connections on mine and wiring was able to handle a lot more than next fuse size up. I couldn't find any reason for over-heating and standard fuse did get warm. Next size up was cool and I fitted it as a temporary fix. Of course I never got around to doing anything about it and that was about 9-10 years ago.

[NZL50505]

The reason I upsized my fuse from 15A to 20A was that I observed what happened very closely to the current draw during ignition phase - as the Webasto unit is first starting up from cold it draws a big current - in my case I frequently saw 18-20A for a few seconds then it gradually dropped down into single figures and settled around 3-4A whilst running normally.

So from this I was surprised that the 15A fuse didn’t blow earlier. Hence I had no hesitation in increasing to 20A. Which worked fine from then onwards.

[Mistroma]

Same with my old Eber unit and I expected the same with the brand new Webasto. Wiring was well up to the job but the original plastic fuse top looked like something Dahli had drawn. The replacement also got quite warm and I fully expected it to melt eventually. A step up in fuse size seemed reasonable given the startup current and the fact that all connections seemed sound.

[iduna2]

3500 Airtop heater
Jeanneau DS43, 2004

Our heater is running but it is pushing out only cold air. No error codes. No idea where the fuses are. Have looked everywhere.

Help, please.

[sailor666]

First thing to check is the heater thermostat setting. If it thinks it is warmer than the thermostat setting then it will just pump out cold air. Turning it up to something high would eliminate this possibility.