There are two main players in the market offering quality diesel heaters: the D2 2.2kW and the D4 4kW from Eberspächer (Dometic). Then there are the 2, 4 and 5.5kW Webasto diesel heaters. Dometic and Webasto are good brands with little or no trouble reported. Of these the Dometic would be the most popular.
There are cheaper brands such as Panar sold on eBay, but at Northern RV we stick with the tried and true brands as we know that once we have fitted the unit, we are guaranteed of customer satisfaction.
Diesel heaters are especially popular in motorhomes as most vehicles don’t need to fit an extra fuel tank. Instead, a probe is fitted to the motorhome’s main diesel tank that picks up the fuel supply for the heater, although you can still opt for a separate 10-litre diesel tank.
With gas heaters the 2.4Kw (Dometic) Truma E2400 seems to be the only contender and this is also a good quality unit. There is the Truma Combi that combines hot water and heating and while this is a very good system, it’s more suited to being fitted to a new motorhome as opposed to an aftermarket installation.
Both gas and diesel heaters are perfect additions to a motorhome or a caravan.
A diesel heater can be fitted in many areas but under the bed seems to be a favourite location and often it’s the most practical. The air intake is installed on the side of the bed with an outlet pointing directly down the centre of the motorhome to give maximum heating effect. The controller needs to be installed a little above waist height – halfway on a gable or cupboard – as this houses the thermostat. If you install it too low, the unit will keep running as the hot air is up near the roof and the reverse happens – if you install the controller too high it will cut out too early.
The Eberspächer diesel heater has three heat settings it automatically selects during operation, based on the thermostat reading. This makes the diesel heater very fuel efficient, and allows it to maintain a constant temperature.
Fuel consumption for the diesel heater is very economical, using between 0.11 and (at maximum output) 0.51 litres of diesel per hour. The diesel heater is a completely sealed unit, meaning the burners are fully enclosed and oxygen used in the combustion is drawn from the outside via the air intake and the burnt fumes are expelled via the exhaust under the motorhome.
For motorhomes/caravans between 14 and 22 feet in length, a single outlet is usually sufficient. Half an hour is enough time for these units to heat the space to a more than comfortable temperature. Twin outlet diesel heaters are sometimes suited to larger motorhomes or smaller motorhomes with unusual layout configurations. The heating unit is the same size, but you install an extra outlet and ducting to reach an extra area including the ensuite if it’s accessible.
For very large motorhomes, caravans and fifth wheelers it may be advisable to look at the larger four- and five-kilowatt models and extra ducting and outlets.
While diesel heaters do come with a muffler, you can hear the noise from the intake (very minimal). However, there is also a ticking noise from the fuel pump, it`s not overly loud but it’s audible and is best mounted away from the sleeping area where possible.
As with any appliance it is advisable to get the unit serviced at least every 500 hours, mainly to include cleaning of the glow pin. If you interrupt the power supply while the diesel heater is in operation you can damage the glow plugs because burnt fuel will adhere to the glow plugs as the unit has not had a chance to go through its cleaning cycle.
It is also advisable to use a premium diesel fuel when filling the tank as some truck diesels are not as refined and can cause problems with continued use. For those that are handy, you can install these units yourself by following the detailed instructions (or a YouTube video). At Northern RV it generally takes our installers around five hours to fit a system in a motorhome. It can be a little longer depending if there is a sub floor involved.
The Truma E2400 is a very economical unit, and a little more powerful at 2.4kW. In the economy stakes it uses 170 g/h (grams per hour) therefore a 9kg gas bottle would run the heater for 52 hours on maximum output. The E2400 gas heaters have completely sealed burners, meaning the oxygen used in combustion is drawn from outside through the air intake and exhaust fumes are expelled outside via the flue. Importantly with gas heaters, the flue has to be located a specified distance from an opening window, or a door, and not in the proximity of other gas/electrical appliances, and cannot be vented into the annexe area.
The gas installation by law must be performed by a licenced fitter and a new gas compliance certificate must be issued. The E2400 gas heater only has on/off settings automatically controlled by the thermostat. The thermostat has a setting of one to five, this means that it can be a little bit more temperamental when trying to maintain a constant temperature. The thermostat should also be installed at waist height or halfway up the wall. The fridge wall is not ideal as any heat generated in the fridge cavity will interfere with the thermostat.
A Webasto system
The ideal place is if you have robes each side of the bed, install the thermostat there and you can switch it on before you get out of bed on those cold mornings.
You can fit the E2400 units yourself but the gas side of the fitting must be done by a licenced gas fitter who can issue you with a gas compliance certificate, and you would also need to know the regulations about where you can locate the unit and the flue. At Northern RV we strongly recommend that you do not install the E2400 yourself as there are many regulations you need to comply with. Worse, you could cause yourself or someone else serious injury and void your insurance.
Diesel heater control unit
Both diesel and gas heaters are extremely good options and it mainly comes down to regulation stipulations on the gas and individual requirements; pricing is very similar.
The gas E2400 is slightly quieter but both units are reasonably quiet when compared to running your reverse-cycle air-conditioner but if you are free camping this is not usually an option anyway.
Written: Wed 01 Jun 2016
Printed: June, 2016