Webasto Dual Top

Webasto Dual Top

Information

The Webasto Dual Top Evo 6 is used for in cabin heating and water heating. This was installed in all models up to circa September 2018.

 

Suggested Dual Top Spares Kit:

  • Part # 9019412B – Burner with glow plug
  • Part #9019415C – Gasket kit

Problems

Water Leak (Gasket)

We had a slow but steady Webasto Dual Top leak (as with all water leaks, listen for the pump cycling when it has not been used). It seems to have been caused by a faulty or poorly installed gasket.

 The images below show the telltale watermarks and also the location of this cover on the dual top.

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Here’s what we did.

1. Remove hose clamps and hoses from the heater side of the dual top, not the side with water lines.
2. Undo the 8 screws (torx 25) around dark plastic end cap that sits around the whole end of the dual top unit. Slide off (be careful of the electrical attachment connecting the dual top to the end cap, lots of slack though)
3. You should now be able to see the fan and gasket (see one of the photos)
4. Check for water marks (see one of photos) water marks indicate a leak
5. Undo the two bolts holding in the gasket BUT NOT ALL THE WAY. There are four parts to the gasket, a back plate and rubber seal that go inside the dual top, then another rubber seal and front plate that go outside the dual top. The dual top itself is sandwiched between the rubber seals. So do not undo the bolts all the way or the rear backing plate and seal will disappear inside the dual top.
6. With the bolts undone almost all of the way you can wiggle the back plate and seal out.
7. Check for seal issues (see photo). Ours was installed ‘bound up’ so the back runner wasn’t touching at one upper area.
8. Replace seal if necessary.
9. Reverse procedure to re-install.

I am no mechanic, this was an easy diagnosis and should be as easy a fix.

(James Young)

Replacing the Burner

This is a follow-up on our dual top failure. Feel free to read my previous post about the symptoms that led up to it finally not working at all.

Irv Leach contacted me offline to show me a picture of what his burner looked like when he removed it after experiencing the same symptoms. Sure enough, ours looked the same as his (see photos).

With tips from Webasto support as well as Tracy Pospeshil and Michael Fox (Webasto contacts) on FB I was able to order a new burner and gasket set and get them installed. The hardest part was getting the unit out of the camper. The exhaust and water dump hose have to be removed from the bottom via the rear storage compartment, and of course all the heater ducting, water lines, fuel line and control cables need to be disconnected under the seat before unbolting then finally removing the very awkward shaped unit. Be sure to drain the water from the unit per instructions in the manual or it will weigh much more.

Once removed I went about removing the intake end of the unit, taking pictures as I went so I’d know how to put it back together. Make note of how the glow-plug goes into the burner because the new plug (included with the burner) needs to be installed into the new burner. New gaskets MUST be used (the old blue one was brittle and easily broke after I removed it). Also make note of routing and connecting of various wires, connectors and the fuel line. Pictures really help.

Tracy provided these tips:
· Everything goes on/in/together one way so if it doesn’t feel or look right, it might not be.
· Before removing and reinstalling the end cap, put a little cooking oil on the two metal water lines. The grommet that they push through can come dislodged easily.
· When installing the burner, that looooong fuel line will likely get bent. Don’t worry about it, just get it close to the proper shape and you’ll be fine. (see the next point).
· As soon as the combustion air fan and motor are bolted in place, spin the fans by hand and listen for rubbing. There should be no noise. If there is, double-check that the fuel line that is not under the fan is not rubbing on the underside.
· The wiring connectors on the control module are similar to one another. They only go in one hole, and in one orientation.

While you have the dual top out of the camper it’s a good idea to check the water plug on the opposite end of the unit (see photo). A couple owners had water leaks at this plug. Read previous posts to learn more about it. It would be easy to fix while the unit is out. Ours was fine and still had the factory blue paint seal on it.

After reinstalling the unit in the camper, hooking everything up and filling it with water I turned the unit on. It fired up the first try and it’s working great.

I’m going to attempt to clean our old burner up using brake cleaner spray and a soft wire brush to remove the carbon buildup. I’ll keep this as our spare, along with another gasket set.

I had asked for a dealer recommendation while talking to the Webasto hotline. I was given the info below and they did a fine job. Of course you could order the parts from any Webasto dealer. I did learn they don’t all charge the same for the parts.

We purchased thru Thermo King of Pittsburgh PA. Phone is 724-863-1555, then 2 for parts, and 2 again for Tim Simkovic.

Parts needed:
Burner #9019412 (comes with a new glow plug) I think this was $231
Gasket Set P/N 9019415 about $30
Plus taxes and shipping

(Dennis York)

 

dual top inside

Taking things apart to get at the burner.

burner location

That’s the burner in the middle. Wires go to the glowplug. The horizontal tubing is the fuel line (be careful not to bend the new one when installing).

old vs new burner

Old burner and new burner. Glowplug not yet installed on the new burner. Note the carbon buildup on the old unit. DO YOUR MONTHLY MAINTENANCE TO KEEP THIS FROM HAPPENING! 

Tips

Monthly Burn Off 

As per Webasto instructions a monthly ‘burn off’ is recommended to keep the system running smoothly. It is an easy task, see the INSTRUCTION MANUAL for more information.

(James Young)

 

Tank Disinfection

In case no water has been taken from the water supply system for a period of a week or more, drain the whole water system and rinse it thoroughly before refilling it.

See the INSTRUCTION MANUAL (Paragraph 7.1) for more information.

(James Young)

 

Tank Descaling

Depending on the hardness of the water, used for heating in the Dual Top Evo 6, scaling and lime deposits can form in the coolant hoses and the boiler. In order not to restrict the water quality and the heater efficiency, it is advisable to conduct descaling regularly depending on the water quality.

See the INSTRUCTION MANUAL (Paragraph 7.2) for more information.

(James Young)