Marine Diesel Heaters: Stay Warm On Those Cold Mornings and Nights

Boating is possibly the ultimate summer activity, but when the seasons begin to change and the winter weather sets in, you'd be hard-pressed to find many people out on the water. For most boat owners, their decision to retreat to dry land isn't driven by the conditions on the water but by the temperatures onboard their boat, most of which are designed with soaring summer temperatures in mind.

So, what can you do to extend your boating season deep into winter? Invest in a marine diesel heater. In this Buyer's Guide, we'll walk you through the benefits of a marine diesel heater and answer a few common questions about installing one on your boat.

What is a marine diesel heater?

Unless you live aboard your boat or have spent time away from Australia's warm waters, you've probably never needed a marine diesel heater and might be wondering what it is. As the name suggests, a marine diesel heater uses diesel to quickly and efficiently heat a space.

Marine diesel heaters typically have an external fuel tank that is separate from any onboard fuel sources - this is especially true on boats. A fuel pump drives the diesel into a combustion chamber, where the heat from its combustion passes across a heat exchanger and is blown by a fan through a nozzle as a stream of hot air.

There are many brands that manufacture marine diesel heaters and they can range widely in price, from cheap Chinese models to high-end, European-made heaters. Here at Shop RV Parts, we exclusively stock Eberspacher marine diesel heaters, which are considered by many to be the market leader in marine diesel heaters and have been nicknamed the 'Mercedes Benz' of diesel heaters.

What are the benefits of a marine diesel heater?

Marine diesel heaters offer many benefits that make them popular among boat owners. Firstly, they are easy to use and will heat up a cabin quickly - an essential feature on a cold day. Secondly, marine diesel heaters are known for being highly efficient and having low fuel consumption, which makes them very affordable to operate.

Additionally, marine diesel heaters tend to be a lot 'smarter' than traditional gas or electric heaters, and will automatically adjust their fan speed and output to keep the temperature at a consistent level without any major fluctuations. Finally, marine diesel heaters are incredibly safe: not only does diesel have a very high combustion point, but the combustion chamber is sealed so there is no open flame, and the exhaust gases are vented safely outside so that there is no unsafe buildup of carbon monoxide.

Where do you put a diesel heater on a boat?

Where you choose to install your marine diesel heater will depend on the design of your boat. For instance, it is not worth installing a diesel heater in an open cockpit as all the heat will simply disappear into the air - you are better off installing it in an enclosed space such as the fore cabin instead.

However, if your boat has an enclosed cockpit or wheel house, you will have no issues heating the space. Wherever you choose to put your diesel heater, it is best to install it towards the floor so that heat can rise through the cabin and the unit can draw in fresh air. For this reason, it is also important to install your marine diesel heater with at least a few inches clearance on all sides to allow for proper airflow to the intake.

What size heater do I need for my boat?

As marine diesel heaters are designed to heat relatively small spaces, there tends to be very little variation in size. At Shop RV Parts, we stock two models of diesel heaters (the D2L AS3 & the AX1 D2) from Eberspacher, both of which are the same size, and are powerful enough to heat any space on your boat without issue.

How does a diesel heater work on a boat?

Diesel heaters work by drawing fresh air through an intake and passing it through a heat exchanger, which warms the air using the heat generated by the combusting diesel. This warm air is pushed out of a nozzle by a fan and heats the space, while the diesel exhaust is vented off outside the cabin.

When installing a diesel heater, there are three main things to focus on: where you will store the fuel tank, where you will mount the control panel, and where you will install the exhaust pipe. The fuel tank can easily sit in a locker or behind a bulkhead with a fuel line running from it, while the control panel can be mounted wherever you have space - either near the wheel or somewhere else.

The most important part of installing your heater is making sure that the exhaust gases are vented in an open space where they will not have a chance to build up. Don't worry though, you don't need to start cutting holes throughout your boat - connecting the exhaust to some ducting or simply running it outside of the cabin will suffice.

Wondering if a marine diesel heater is right for you? Browse the range online.

Although you probably won't freeze during an Australian winter, you'd be amazed at the difference a marine diesel heater can make to your level of comfort and desire to take the boat out on a winter's day. If you're interested in learning more about the different applications of diesel heaters, you can read our other Buyer's Guides here or take a look at the models we currently have in stock.