webasto heater installation

I am in the process of updating the heating system in Pert 'Near a 37 Hershine. I have removed an old hydronic unit so I already have most of the components. I purchased a webasto 2010 used that was previously used on school buses in Alaska. It has been bench tested and ran great for a couple hours by sure marine in seattle. Couple of questions I have about converting it to a marine application.
First is the exhaust the old unit used a 1 inch flexible stainless tube. The webasto is very near the same size however it is recommended to use a rigid exhaust pipe wondering what you fellows have on your webasto unit. I have about 2 feet of ridged pipe from the heater but the remaining 4 feet with be new
My intake air on the old unit came from a 2 1/2 in flexible hose connected from the outside housing of the muffler. I am a little concerned about drawing air that close to where the exhaust exits the hull though its just combustion air. Secondly the intake on the webasto is about 3 1/2 in. will I have adequate air with a smaller hose. Thank in advance for any tips.

All questions that Sure Marine will best answer.

I've had an Air Top 2000 that is basically a truck unit. Bought at SM and installed 10 yrs ago. Got so crudded up it wouldn't run. Took it in to SM and they went through it and recomended I change to kerosene. I did. Finished the all new fuel system about two months ago. Works perfect. I put a new aluminum fuel tank on the outboard side of the aft cabin bulkhead. About 2/3rds copper tube and 1/3 hose. My original exhaust is the max specified by Wabasto (10') and it has been fine. My air intake is from within the space where the heater is installed .. in other words no intake air plumbing.

Do not source your fuel from the engine fuel manifold. Engine lift pump will interfere w the little "dosing" heater pump and intermitant operation will result. Especially at start-up underway. It can be done and works fair. I'll bet others are doing it w relative success (as I did for about 8 yrs) but Wabasto dosn't recomend it nor do I. If there is a fuel outlet at the bottom of a fuel tank you can use that but water and crud getting into the Wabasto system is then a significant posibility.

I'll post a PM for you so we can talk

I had a muffler shop make solid exhaust and also heat wrap the pipe. The intake is just the air from the engine room. I leave a port not shut tight. Fuel is drawn and returned directly from the starboard fuel tank. The webasto has a fuel pump and is self priming. With the webasto in the engine room its a between 60 to 80 degrees and heats the salon floor.

The PO took out the furnace and I am looking to do the same as you. Can you provide pictures of your install progress?

I hope it works out.

I have the smaller Webasto thermo 90. My exhaust is smaller than the 2010 but is rigid and wrapped. Ive rebuilt mine twice and always got good advice from Sure Marine. I'd ask them for advice if any doubt.

Glen

Webasto heater install

jjorgenson3 said:

The PO took out the furnace and I am looking to do the same as you. Can you provide pictures of your install progress?

I hope it works out.

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So far I got the old unit out and am in design stage on a mount that will give me adequate clearance for the exhaust. I purchased from amazon heat wrap for the exhaust and then plan on covering with the flexible metal dryer vent tubing. I will get some pics to post when I get back down to the boat.

Phil Fill said:

I had a muffler shop make solid exhaust and also heat wrap the pipe. The intake is just the air from the engine room. I leave a port not shut tight. Fuel is drawn and returned directly from the starboard fuel tank. The webasto has a fuel pump and is self priming. With the webasto in the engine room its a between 60 to 80 degrees and heats the salon floor.

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Think I will go with solid as well as recommended by Webasto. Got the heat wrap from amazon
and after its wrapped plan on covering with the flexible metal dryer vent tubing.
Fuel supply I am undecided have a free standpipe in the port fuel tank was considering using that with a good filter but on the advice of Manyboats I may go kerosene and a separate fuel system.

When installing the unit be sure to measure the voltage while in starting mode while operating on your battery charger.

Most truck units expect the engine to be on at 14+ volts, and boat starting hassles are from low voltage at the unit.

The use of Kerosene instead of house fuel or diesel is a great way to assure long hassle free operation. Especially if the unit has an off on thermostat.

The Espar has a full and half setting, the least hassle is to let the thermostat select between those 2 choices , if your unit will allow that.

Can you utilize the two part pipe where incoming air cools the exhaust run and the whole thing is wrapped to boot. Sure and other heater manufacturers much prefer this setup, me too. Sure sells these parts and pieces if your heater is initially designed to accept the one pipe arrangement.