Webasto Air Top Diesel Heater service?

Oct 26, 2010
1,904
Hunter 40.5 Beaufort, SC
Does anyone know of a reliable place to send an Webasto Air Top 5000 Diesel Heater to for inspectiona and refurb? I have one I have pulled from my boat and am considering having it check and refirbished or selling it? I checked the Webasto site and can't seem to find an authorized service center where I can send the unit for checkout and repair/refurbishment if necessary. I am located in Beaufort SC so if there is an East Coast center or repair service I'd appreciate the contact info.
 
Oct 26, 2010
1,904
Hunter 40.5 Beaufort, SC
You might call Horton Marine Services in Annapolis.

P.S. -- Was it working? Is it just a check? What's its legend?

Nathan Horton
(410) 693-2673
HortonMarineServices@gmail.com
Nathan, - Here's the history

The heater came with the boat when I bought it in 2012. It was installed sometime before 2007. The PO was a live aboard in New Rochelle, NY and used up there every winter. I don't know the year of manufacture but I am sure its available from the serial number coding somehow. I moved the boat to Annapolis (at Bert Jabin's so I am familiar with it) and then moved the boat to Beaufort SC in 2013. I didn't like the way he had the ducting run and it has a Marine Reverse Cycle Air Con unit and that is plenty for here in the deep South. Air Con is more important down here and I have a NextGen 5.5 if I need to run it while at anchor or use a small electric heater if necessary but that is few and far between.

When I removed the previous ducting it looked like a 3 inch black "cardboard" type material and was a little brittle. For the air conditioning I replaced the black ducting with 4 inch aluminum dryer ducting and then insulated that ducting to reduce sweating around the ductwork. I don't know if the insulated aluminum ducting is suitable for use with the diesel heater, which will influence my decision whether or not to reinstall it or sell it. I have a dealer for Webasto in Charleston SC who is getting me the info on the factory contact because he says he can't run it removed from the boat and it would have to go to someplace that has the equipment to bench run it to check it out and do whatever service is necessary.

It was working when I bought it but the PO suggested a service since it was running but not as well as he was accustomed to (whatever that means :huh:) and the ducting was "brittle" which I didn't feel comfortable using if it meant there was some problem with the unit. I removed the whole system including the mount, insulated exhaust hose, exhaust overboard, control unit, fuel supply cutoff, fuel lines - the whole kit and caboodal. I don't feel tackling this is within my skill set since I don't have a way to test until I reinstall it and thats a lot of work if my service is "unsuccessful." I have all the Installation, Parts and Service manuals so installation is within my skill set but it would be a lot of work if it doesn't work after installation. I don't feel comfortable re-installing it without a complete checkup and service and certainly don't feel comfortable selling it if I don't know it's exact working status. I think this unit was somewhere around $3K to $4K new for the heater and all the accessories. I really hate to just "chuck it".
 

SG

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Feb 11, 2017
1,670
J/Boat J/160 Annapolis
I'd give Nathan a call.

While he handles Espar heaters as a dealer, but he services a lot of different systems (including Air Conditioning and dedicated heaters). I've worked with him for over 15 years, or so.

I've had Espar heaters on our current and former boat for over 30 years.

You clearly need to use a supply dedicated duct work system for the diesel heater and the air conditioning. I don't think the ducting with rigid duct work is that much an issue per se. The insulation is usually a consideration; and, how the return is handled. That's assuming that you have the duct work "pipe" diameters sized adequately and sealed the joints.

Assuming the unit is working alright, to me, the service issues are i) glow plug, ii) blower motor, iii) control systems, and making sure the combustion chamber and other parts are sealed.
 
Oct 26, 2010
1,904
Hunter 40.5 Beaufort, SC
Thanks SG. I'll give Nathan a call. I get up to Annapolis or at least the DC area every so often. "Assuming the unit is working alright" are the operative words. Since I have never operated it (should have before I removed it but that is water under the bridge) I have no idea of its status. I don't want to spend the money to do a service and then install it and discover that I did not find the right easter egg.

My duct work is not rigid ductwork but rather the flexible thin walled dryer duct 4 inches in diameter wrapped with insulation. Not sure if that will work for the diesel heater. It works fine for the A/C unit though.
 
Dec 25, 2000
5,732
Hunter Passage 42 Shelter Bay, WA
My duct work is not rigid ductwork but rather the flexible thin walled dryer duct 4 inches in diameter wrapped with insulation. Not sure if that will work for the diesel heater. It works fine for the A/C unit though.
Our boat has the same type reverse cycle heat pump ducting, though a bit heavier than dryer ducting. The Wallas forced air furnace that I installed several years ago uses three inch ducting. Rather than replace, or use that starboard side route, which we still use for heating while connected to shore power, established a new route on the port side for the Wallas ducting. That has worked quite well.
 

SG

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Feb 11, 2017
1,670
J/Boat J/160 Annapolis
I'd speak with Nat (or someone else who knows the Wabasto), bot my sense is that really hot connection is right at the discharge for the unit. After that short section, the issues are more i) seal of the system, ii) smoothness of the inside of the duct work, iii) routing, e.g., a flexible elbow or other elbows and bends add resistance. Using the AC duct work isn't a good idea, to me. First, you'll be blowing a bunch of hot air back through the AC unit, and secondly, you're trying to maintain even velocities and pressure through the system.