Intermittent Webasto AT 5500

[Jim Gandee]

Crew,

I realize many of you will chuckle when I say it's been cold here in LA but we've actually had some cold nights of late. It's been dipping into the 40's at the marina and colder inland. Definitely cause to fire up the wonderful Webasto. But alas it has only decided to blow hot air intermittently. The fault code indicated failure to light. (No kidding. I figured that out all by myself!).

Today I disassembled the unit and discovered the igniter severely crusted over with carbon deposits or coke. I cleaned the unit up and will reinstall the heater tomorrow hoping the problem is resolved.

Side note- the parts manual indicated my unit has a ceramic heating element, vs a glow plug, which should last the life of the heater. Can anyone familiar with these units confirm that by looking at the posted pic?

Happy New Year!

 

[Larry M]

I'd send the picture to Sure Marine in Seattle and have them take a look at it. They are probably one of the most knowledgeable service centers/dealers of Wabasto systems in the US.

Sure Marine Service, Inc. * Since 1972 * Webasto Marine Heating, Air Conditioning, and Galley Equipment

 

[Jim Gandee]

Good idea Larry!

 

[folivier]

Don't know if the Webasto for boats are the same as used in Aquahot hydronic heaters, but Roger Berke is a good source and very helpful in troubleshooting Webasto burners. And Rudy Leggett in Beaumont, TX is a fantastic tech. He mostly works on Aquahot in motorhomes but could possibly help with troubleshooting. PM me if you want his contact #.
Webasto Parts

 

[Nomad Willy]

I just converted mine to kerosene as directed by Sure Marine. They say it burns very much cleaner. I did get 800hrs on mine before it just wouldn't start.

However my problems (other than dirty diesel) was fuel delivery and start up.

 

[Jim Gandee]

Follow up- the reason I removed the heater was due to intermittent ignition. I'd have to cycle the thermostat on several times to get the heater to light, but eventually it would. I cleaned the burner thinking that would solve my problem but it didn't. The burner definitely needed cleaning so not a waste.

I spoke to Dan at Sure Marine ( Thanks to Larry M. For the tip) who opined the intermittent starts are often caused by a small leak in the fuel line. The leak can be so small as to not drip fuel but allow air into the line which causes a loss of prime. The heater start cycle only allows the fuel pump a short cycle time before cut out, this is a safety feature. With air in the fuel line the short fuel pump action is not sufficient to recover from the loss of prime. Subsequent start attempts permit the pump to finally overcome the loss of prime allowing the unit to start.

Cutting to the chase, I discovered the flex fuel line between the fuel pump and the copper fuel line had hardened and shrunk and the clamp was at the end of its clamping limit. The fact that the copper fuel line has no flute makes it more difficult for the flex line to seal. So after replacing all of the flex line and clamps I once again have a working heater!

 

[fractalphreak]

I love this forum!!! While out this week we started having intermitent start issues with our Webasto TOP 40 EVO. Not having much else to go on and no experience with these units we were at a loss. After finding this post, I discovered the same issue, old fuel hose onto non-barbed straight pipe that wasnt a tight connection any more. I dont have new fuel line on board but moved the clamp to a better section of hose to get us through a chilly week out.

Thank you!

 

[Jim Gandee]

Fractal, Glad you were able to get that heat on! I hope your fix made you out to be a hero to the crew!