Diesel heating secrets

When it comes to RV travel, there is no doubt we are spoilt for choice these days. This is never more so than when trying to keep warm in your RV. In this article, we look at the trend of fitting diesel heating and why this solution is becoming increasingly popular in the market.


We decided that the time had come to fit heating to our RV as an aftermarket accessory. When selecting an RV heating solution, it came down to three choices – 240v electricity, LPG gas heating, or diesel heating. We were aiming for a DIY solution so selected the diesel heating option.


The ducting can be routed around the RV as desired


Diesel vehicles and heating in Europe is nothing new. It was originally designed as a means to pre-heat engines in sub-zero climates. These designs were enhanced with heat exchangers enabling an economical, warm and safe heating solution to be brought to the market.

Technology over time has grown and adapted to motorhomes as the fuel source is already on board. Later it was extended to the boating industry and more recently to caravans and campers.

Heating demands have grown, resulting in an increased number of manufacturers. Competition has led to improved manufacturing techniques and lower costs, making the diesel heating solution now quite affordable. Manufacturers are keen to work with the RV industry and have improved their designs and specifically tailored their solutions.

With clever designs, manufacturers now make a range of products that can be adapted and used in the OE and aftermarket arenas. One big advantage diesel has over other products is the kits can be fitted by a DIYer which can save you big dollars.

Once installed, the diesel heating system is a complete standalone unit and only requires connection to a 12 volt power supply via house batteries. Having the ability to heat your RV’s cabin air regardless of your location is a great advantage. Very cosy!



There are many components that make up the unit, so let’s take a look in detail.

Diesel and Storage

Firstly we need diesel fuel. The beauty with a motorhome is you already have diesel on board, so really it’s just a matter of gaining access to that supply. On the other hand, a caravan needs to have a tank added.


There needs to be a pump that can deliver the diesel to the heating unit. These pumps are designed and calibrated to deliver exactly the required quantities by using a displacement dosing style of pump.


A correctly designed hose that won’t break down is used to carry and deliver the diesel fuel to the heater.

Heater Unit

This is the heart of the heating solution with the type and manufacturer varying.


Mufflers and exhaust style pipes are used to remove the combusted exhaust gases.

Electronic controls

Small micro-processors are used to control the system. Signals are then sent to the supply pump, the heater unit and the fan module which controls the diesel supply and the heat energy generated.

Wiring Harnesses

Wiring is used to connect all the components and carry the 12v power from on-board batteries to operate pumps and valves.

Ducting and Outlets

Ducting is used in a variety of ways to supply fresh air to the heaters combustion chamber.

A different style of duct is used to take ambient air within the RV to the heater unit. Additional ducting is then used to distribute the heated air to locations inside the RV.

A kit comes with everything you need and each component is labelled





Let’s take a look at how this process works (refer Figure 1).

  1. Metred amounts of fuel enter the unit from below.
  2. Fresh air for combustion also enters the unit from below.
  3. This ratio controlled diesel fuel and fresh air are mixed together in the combustion chamber of the heater (orange colour).
  4. Using a glow pin, the mixture is ignited. Combustion takes place and heat energy is produced.
  5. The heat energy is transferred to the surrounding metal heat exchanger (red colour). The spent fired mixture of diesel and air is exhausted below into the exhaust muffler system outside the RV.
  6. A fan draws air from inside the RV into the heater unit (blue arrow) and this air is passed over the heat exchanger (red colour).
  7. This fan-drawn air is heated as it passes over the hot metal surface of the heat exchanger, and then exits the heater unit via the air outlet (red arrow).
  8. 12 volt power is used to operate the fan and associated electronic modules.

In summary, we take the cold air inside our RV and blow it past a hot metal cylinder with a fan. The cold air is heated and we now get a stream of warm air. Gradually this circulated warm air continues to be warmed each time it passes the hot metal cylinder keeping the air inside our RV heated.

The combustion process is very precise and is contained within the burner cartridge



As we all use our RVs differently, the lifestyle we choose can have some bearing when it comes to selecting your heating solution. Here are some things for you to consider.

  • You need to have space in your RV for the heater unit. Unlike other heating products that require venting and have clearance requirements, diesel heaters don’t have compliance
  • Allow for the extra weight required in your RV for an extra fuel source.
  • Unlike other vessels, you have flexibility for locating the diesel tank.
  • Refuelling is available wherever fuel for a diesel vehicle can be bought.
  • Diesel is economical to run.
  • Diesel heating doesn’t consume capacity needed to operate other RV appliances.
  • Kits can be bought to suit an aftermarket installation by a competent DIY installer.
  • Purchase the kit from specialists in the business with a proven track record. Confirm they offer a comprehensive warranty and guarantee, and have service agents throughout Australia.
  • Review the manufacturer’s amperage consumption on your batteries as they are not all the same.