Review - Autoterm (Planar) 2D-HA Forced Air Boat Heater

Having an Autoterm (formerly Planar) heater installed on my boat was one of the best boating purchases I’ve ever made.  Originally, getting a little heat going in the cabin during the winter season was the main impetus for this addition, but interestingly, in practice that has almost become a secondary benefit of this unit.

This boat is based in Vancouver BC, Canada and charters year-round mainly in local waters. We are lucky in southern BC to have relatively mild winters, and while temperatures can dip to the freezing mark and sometimes below ( -10 C is really cold for Vancouver), in recent years, snow and ice have been factors for only a couple of weeks at most, even in our worst winters.

The marine environment however, is always damp, especially on the often rainy west coast, so regardless of the season, steamed up cabin windows and windshields are an almost constant annoyance - especially first thing in the morning.  And, nothing keeps them clear like a forced air heater!  You can dress for cold weather, but on some days, it seems no matter how much you wipe, or with what, the cabin windows just want to keep on getting steamed up.  So it might sound funny, but I find I use the heater as much for a window defroster as a heater.

The unit I have is the Diesel Air Heater Autoterm 2D-HA, which is rated for boats up to 25’.  And while it is called a diesel heater, this unit will also run on kerosene, which I prefer as there is no associated diesel smell coming out of the unit.

The total system consists of the heater itself, a fuel tank, controller switch, through-hull exhaust, and all the necessary ducting, ducting connectors and several different style vents according to your desired configuration.

mounted position of Autoterm heater unit.

The main heater unit is 324 x 118 x 119 (LxDxH; mm), which is about the size of a large loaf of bread.  Mine fits nicely under and beside the port side front seat (as shown).  I have the smaller 7 litre fuel tank which fits also well in the locker under the port side rear seat (as shown).  Larger fuel tanks are available if you have the space, and while that would be nice, I can run my heater for at least 7 hours off a full 7 litre tank of kerosene.  I have four vents coming off this unit - two for the windshield, and two more which point at the driver and passenger.  This is the maximum number of vents this unit will handle, but where they go depends to a large degree on what you want and where the space is on your boat.

7 litre fuel tank.

Other than that, there is a just the controller of which there are few choices ranging from basic to others which have timers, thermostats etc built into them.  For my purposes, the basic on/off controller with a dial for the amount of heat works just fine.

Operation is a simple on/off push of a button.  The unit takes a couple of minutes to heat up, and depending on on where the heater unit is, you will hear it as there is a fan involved.  It is nothing serious and if you have the space to put it as far away from you as possible the sound factor will be diminished to almost nothing.  My boat has a canvassed enclosure and not a completely enclosed cabin, but this heater keeps the “interior” noticeably warmer than the outside temperature, even with the back door “flap” open, even in relatively cold and windy outside temperatures.  And, as mentioned, it does a terrific job of melting frost off the windshield and keeping the windows clear of moisture.  In an enclosed cabin situation with the door closed, at full heat, I have no doubt it could pump out enough heat to drive you outside.

4 vent positions - passenger and drivers side vents are louvered, and left and right windshield vents are directional..

I had my unit installed by the local Planar dealer, and not only did they perform the best  and cleanest install of almost any piece of any equipment I’ve ever seen, I also learned a lot about the process from watching them.  You can install these units yourself, as the system itself is not overly complicated, but installing it is very involved and requires a lot more planning and tools than you might first think.

Along those lines, if you do choose to self-install, one important tip I got from the installers was to always wire the heater unit directly to your battery and not through any kind of master switch that can be shut off. This heater needs to cool down fully before shutting down and if you have it wired through a panel or switch such that it could inadvertantly be shut off before this cooling process has completed, it could lead to the unit overheating or catching on fire.

The most complicated and troublesome part of the installation is definitely planning where all the components will go, and drilling all the holes required to fit your plan.  If you choose to self install, you will be drilling lots of holes of various sizes in your boat, including a through hull for the exhaust.  As space is always limited and awkward in a boat, getting these holes drilled in the positions you need them will be the most frustrating part of the whole exercise.  A right angle drill and bits ranging from small to a 2 - 3” hole saw is almost a must, as well as the ability to contort yourself into small and awkward spaces.  If you have lots of tools and the experience and patience for projects like this, as mentioned, the system is not overly complicated and definitely do-able. If not, I would strongly suggest professional installation.

There are far cheaper versions of these forced air heaters on the market, sometimes referred to as “Chinese heaters” as many are made in China knock-offs. And while the price differential certainly makes them tempting, I personally was not comfortable going that route for the following reasons. These units get really hot and fires on boats are another level of serious compared to fires on land. Also, the parts needed for every installation will vary widely depending on the configuration and space available on your boat - so buying a cheap, one-size fits all kit online is not likely to work for everyone, and getting specific additional parts from the cheaper manufacterers would most likely be problematic. In short, if something sounds too good to be true, it probably is, and that was my take on the cheaper heaters.

There are also far more expensive versions of these heaters available, but for an under 25’ boat, the Autoterm for me hit the optimal price point to quality and reliability considerations.

They are highly rated and reviewed online, and my experience with them after about 3 years of fairly steady use has been nothing but positive.

So if you use your boat more than just on the best and warmest days of summer, and/or find yourself always fighting with fogged up windows, one of these Autoterm heaters will make a big difference to your time on the water.

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