Webasto 3900 Placement

[AKDoug]

Hell all,
I have a new heater in shipping, so now it's time to figure out where to mount it. I am looking for input on where you mounted your heater and how satisfied you are with the sound level while it is operating. In the cabin, in the engine compartment, under the back deck, or wherever you may have mounted your heater.

How you routed your intake/exhaust line and where it exited the hull might be nice to know as well.

I have several options, but the easiest to service and maintain would be inside the cabin under the counter. Second best choice might be under the cockpit deck outside the main cabin, but requiring longer runs for fuel and air.

Hoping for some good opinions and information! Thanks folks

 

[FF]

Decide where you want to be when it craps out during a snow storm with light icing.

These units need to be serviced annually at least , and do not lift far from a fuel tank.

A stand alone gravity fuel tank with #1 diesel or kerosene is best if the unit has a thermostat .

Install it with #10 or #8 wiring as many start at lots more amps than the mfg states.

AS truck/bus units they work best with engine on 14.4V , not a battery charger float 12.8 and long wires.

 

[Phil Fill]

I believe the 3900 is an air unit and air cool quickly so it should be install close to where you want the heat. The unit has its own fuel pump so it does not have to be installed real close to the fuel tanks

 

[AKDoug]

I am more looking to find out about noise levels in the cabin(s) based on where the unit is located. My boat is small (as you can see) so my options are limited. I am leaning towards behind the sink under the counter inside the cabin.

The exhaust run should have the cold air intake around the exhaust hose outlet, so heat shouldn't be an issue for the exhaust. I am not really happy having it exhaust on the stbd side of the boat, as I do as much docking as possible stbd side to. I also kayak, fish and shrimp, so exhaust placement should be away from where I play if possible.

The wire runs will be very short, oversize (as always), and probably done by a professional this time around. I am tearing out the counter top for a new oven and stove, so I am replacing the sink as well and would like to get the heater done in the same upgrade, all in one shot. That would be all of my stbd side upgrades in one whack and ready to go for the year.

 

[Phil Fill]

The loudest noise is the exhaust on the outside. Sounds like a RV water heater. Is you insulate well there should quiet on the inside. Actually I like being able to hear so I know when its firering or not. Install the exhaust as high as possible above the water and or dock. The exhaust is hot about 6 inchs.

We have serviced every year as it runs 24/7 from October through May.