heater

Diesel Air & Water Heater

Hot water and heatered air is provided by a Webasto ThermoTop E diesel-powered heat exchange system. It provides on-demand hot water and warm air. The maximum water temperature can be controlled via an inbuilt tempering mixer valve.

The Webasto ThermoTop E is rated at 12V, 4.2kW. Model 10R-04 1232, 122R-00 0003.

The diesel fuel supply is from the main tank with a low fuel consumption of only 0.22 to 1.0 litres/hour.

The Water Pump, Pump filter, Webasto Heater, Warm-air fan-forced Radiator, Tempering controls and the Drinking Water Filter are accessable below the RH camper seat.

These are housed in their own fibreglass sump with an evacuation valve to dump external of the camper in the unlikely case of a failure in the plumbing or heater fluids.

Note that the Circuit Breaker for the Heater, located in the panel below the Touch Screen, must be ON for the heater to work at all.

By pressing the rocker switch below the RH camper seat the switch is illuminated red and the Heater commences its start-up cycle. Hot water is available within 10 minutes.

Remote air heater switch in the wall at the bed head.

A separate two-stage switch illuminates green and runs a fan pushing air through the Heater radiator matrix to heat the room.

Turning off the rocker switch starts the Heater shut-down cycle, which takes some time.

On cold mornings it is nice to run the room heater for half an hour to warm things up before getting out of bed. A remote switch for this purpose is located at the head of the bed. A side benefit is that there is then also hot water available.

Modifications

The Webasto ThermoTop E is rated at 12V, 4.2kW, S/N 1D1421070184. Model 10R-04 1232, 122R-00 0003.

There were some issues with the original installation of the heater in TT30:

The Webasto activation switch, on the side of the base of the driver's side camper seat, was very easily knocked, inadvertently starting the heater.
The activation switch was illuminated all the time; a green LED next to the switch would come on when the switch was turned on; the heat exchanger fan had no indication for it being on.
It was not possible to turn on the heater and fan from the bed in the morning to warm the camper before we arose.
The heater runs to keep the water to a set temperature; this has very little relationship with the air temperature.

Recessed Webasto switch

Wiring behind the Webasto switch

I mounted the Webasto switch behind the switch panel, instead of in front of it, using four small nuts and bolts.

I rewired the Webasto switch so that its internal LED is on when the switch is on.

I changed the wiring to the green indicator LED so that it illuminates when the fan switch is on full or half speed. This required adding a couple of 1N4007 diodes.

I spliced in a length of 7-core trailer cable from the switches to the bed side of the kitchen bench and connected to a Carling-type double-pole rocker switch that matches the others in the camper – the remote switch. The switch is wired in parallel with the Webasto switch and with the fan switch on full speed. Separate +12 V lines are used since the supply to the fan is separately fused. The wiring diagram is colour coded to show the different wires.

Wiring of the switches for the Webasto heater, fan and remote control.

Switch with guard.

Switch in wall at the Bed Head

The remote switch is set into a plastic guard to make inadvertent activation less easy. I made the guard from a section of 7-day pill box. The cutout is 38 mm x 21 mm and the guard walls are approx. 14 mm high.

Fuel Supply for Heater

The diesel supply to the heater originally came from a small tank attached to the auxiliary fuel tank. However an internal baffle in the auxiliary fuel tank failed during a remote travel and the tank leaked. It was eventually replaced in Alice Springs at huge expense, the job done poorly. Since that tank had no attached tank, I asked that the diesel supply be taken from the main fuel line, downstream from the Pre-Filter. This has proven to be very successful.

Servicing the Heater

A good reference for servicing this kind of heater is by Le Tonkinois Varnish.

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