Another weekend of Webasto Furnace installation fun. I decided to put the exhaust thru-hull on the starboard quarter instead of on the transom, because the access from the lazarette is much better. A misstep in the thru-hull install; I neglected to read instructions, and drilled the hole without the 1/8" air gap required or the high-temp bedding material. Had to take it apart, redrill the hole, clean everything up and try again.
I glassed in a marine plywood mounting bracket on the starboard hull to hang the furnace from that gives me a straight line hookup to the hot air ducting as it exits the galley aft bulkhead. I did the same to create a platform for the 6 gal. aluminum day tank. The day tank will fill from the main diesel tank via an electric fuel pump and a tee in the line between my primary fuel filter and the engine fuel pump (tee isolated with three valves), with an optional deck fill.
I purchased a Surewire board from Sure Marine in Seattle to simplify the wiring and gain a pump priming circuit and hour meter. This board completely replaces the wiring harness that comes with the furnace, and puts all connections to the metering pump, thermostat, and power supply together in one place. The board and the metering fuel pump mount to the bulkhead adjacent to the day tank and furnace. I placed the thermostat on the galley bulkhead next to the companionway. Probably not the ideal location, but keeps the wire run super short. BTW, Sure Marine has written their own installation manual for these furnaces, MUCH better than what comes from Webasto.
If you saw Part 1 of this saga, you'll remember that we got these Webasto 3900 AirTop EVO furnaces at the insanely low price of $450.00. The install kits, however, were for truck/RV. I've since spent another $1500.00 for ducting, thru-hull, flexible exhaust, insulation, stainless elbows, the SureWire board, the day tank and fuel gauge, and the thermostat. Still, I'll be a good $2000.00 below what the full marine install kit with the SureWire board lists online. I just happy I'm not paying for someone to do the install. Way more work than I had envisioned.
Next steps; complete the wiring, plumb the day tank copper to the pump and furnace, install the day tank vent loop and deck fill. Should be done in time for some hot summer days!
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File comment: Furnace mounted to the new plywood bracket. furnace_install_01.jpg [ 146.27 KB | Viewed 0 times ] Attachment:
File comment: Exhaust thru-hull furnace_install_02.jpg [ 90.55 KB | Viewed 0 times ] Attachment:
File comment: Exhaust system. Fitting on bottom of stainless 90 is for condensation drain coil furnace_install_03.jpg [ 170.12 KB | Viewed 0 times ] Attachment:
File comment: 6 gal. day tank sitting on it's new platform prior to mounting. furnace_install_04.jpg [ 177.65 KB | Viewed 0 times ] Attachment:
File comment: SureWire board and metering pump, partially wired up furnace_install_05.jpg [ 141.08 KB | Viewed 0 times ] Attachment:
File comment: Day Tank fuel gauge furnace_install_06.jpg [ 147.64 KB | Viewed 0 times ] Attachment:
File comment: Digital Thermostat furnace_install_07.jpg [ 122.72 KB | Viewed 0 times ]