Equipment review – Wallas DT30 diesel forced air furnace

As mentioned in our last post, no big sailing plans coming up, but are going to continue trying to document some of the repairs / upgrades we’ve done to Boundary both for our records and for anyone who might be considering similar purchases.

Today we’re covering the Wallas 30DT diesel forced air furnace that we installed in Boundary… with the caveat that this is just our experience, and we have no first hand experience with any other sort of boat heaters (either forced air or otherwise) other than space heaters when we’re at the dock (and those are not very effective).

Overall we’re EXTREMELY pleased with our heater (which is now named “William”, as in William Wallace… yeah, I know, I know…). It heats the boat up quickly, dries the boat out quickly, and doesn’t leave pockets of cold damp air anywhere, it makes the whole space warm and dry.

INSTALL:

• Took a few hours to do it carefully and correctly, but really pretty straightforward, just time consuming because you want to do it right.
• Very legible, clear instructions, and all parts were included.
• Unlike some heaters where you can apparently T off another fuel line, Wallas insists you run a completely separate fuel line (with its own mini filter), which means unless you’re going the day tank route you have to put a hole in your main tank for a fuel pickup; not too big a deal with the plastic tank we have but with other materials could be challenging.
• Boundary had a Wallas heater sometime in the past, so it still had the two vents required (both in very useful spots, one below the companionway steps and one in the steps down into the salon) so we didn’t have to cut holes in fiberglass which can be time consuming.
• We did, however, have to pull the vent hose from the heater to the vents themselves, which was a bit challenging as the hose is somewhat stiff and you have to be careful not to try to go around overly tight corners with it or it just won’t work. If you’re cutting holes to run vents through I would suggest going slightly larger than the vent diameter so it’s easier to pull the vent hose.
• Wiring was very straightforward… 12V power to the furnace itself and then a wiring harness from the thermostat / control panel back to the box as well. Wallas recommends wiring straight to battery because you should never cut the power to it while running (you’re supposed shut it off at the control panel and let it cool down and turn off on its own so you don’t cook the electronics, so that’s the way we always turn it off) but we still went to a switch panel instead of straight to battery just for some added safety / control.

MANUFACTURER SUPPORT:
We bought our furnace directly from the North American importer, ScanMarine Equipment. It was great to go into their shop and see a running furnace and talk directly with the very knowledgeable folks there. What’s more, they swore up and down to call them if we had trouble… exact phrase was “if you have ten questions, call ten times”. Only had to call twice, but they were extremely helpful and knowledgeable both times. And they steered us to a great pub for lunch (Nickerson Street Saloon) to calm our nerves after we dropped a few boat units on the new furnace. They definitely earned their spot on the Credit Where Credit is Due page.

STARTUP:

• First startup takes a while, as it takes a few rounds of trying to start the heater – and having it not start – to get fuel all the way through the empty line.
• But, it’s self bleeding so you just try it a few times and then presto it comes on.

USE:
Seriously, this thing is AWESOME! It does take a few minutes to get up and generating good heat (and it draws quite a bit of power in the first ten minutes), but once it’s going it draws remarkably little power for what it’s putting out… 0.8A – 1.8A depending on how high you have the fan set. I’ve heard complaints about how much power a forced air furnace can use, but to us it’s worth it because it’s actually moving air around in the boat… this goes a HUGE way towards drying things out and warming up the whole boat, not just one corner. Wet clothing dries quickly, the wet dog can sprawl in front of one of the vents, and in general life gets very pleasant very quickly. Our last night at Spencer Spit was cold, wet and blowy and we were all snugged in hanging on our mooring ball. At 0.8A on the low setting it’s plenty economical to run it all night and stay warm and dry. You can certainly hear it running inside the boat, but it’s more a sound of moving air than anything else, and the external noise seems much lower than other boats we’ve heard in marinas (not sure what the other boats’ furnace brands were but some of them are quite loud).

You can also use the Wallas just as a fan to circulate air around in the boat, and we will eventually set up the air intakes a little differently so it draws some fresh air directly from outside to keep the moisture down in the boat, even on warmer days when we might not use the heater if it’s warm and humid we can keep things drier down below if we keep air moving around.

CONCLUSION:
Again, we have no experience with anything else, but we DO have experience with this thing and it’s a game changer in our opinion… highly recommended!