Auto-Sleepers • Berkshire • 2009

It's operated by the switch next to the entrance door - hold it until the step is fully extended; don't try to mount it while it's still moving or only partway out, since the lock won't be engaged and you risk damaging the motor. If you drive off with it left out, a buzzer behind the dashboard sounds once the ignition's on and the step retracts automatically.

Dirt or frost can stop it working properly, so keep the moving parts clean and free of ice.

No, the Trumatic S 5002 heating system must not be installed in motorhomes. Only the Trumatic S 3002 (P) is permitted in motorhomes.

Put out all naked flames right away, don't smoke, switch off every appliance, close the gas cylinder, open the windows and doors, avoid electrical switches, and have an expert inspect the whole system.

Remove the heater casing, slide the battery compartment cover upwards, replace the battery observing correct plus/minus polarity, and close the compartment. Use only temperature-resistant (+70 °C) leak-proof Mignon LR 6, AA, AM 3 batteries.

Wait at least 2 minutes before re-igniting, to avoid any risk of deflagration or misfiring.

Only use temperature-resistant (+70°C), leak-proof Mignon batteries (LR 6, AA, AM 3).

No - Ultraheat can't be used with any S-heater built before 04/2012, nor with the Trumatic S 3002, S 3002 P, S 5002, S 2200, S 55 T, or S 3002 K / S 5002 K.

On electrical mode, run the fan at level 3 or above (manual or automatic) to spread warm air through the vehicle quickly and evenly.

No - Ultraheat (the electric additional heater) is only approved for fitting and running inside a compatible S-heater, never on its own or outside a vehicle.

The additional heater features three operating power levels: 500 Watts, 1000 Watts, and 2000 Watts.

Yes - the S-heater can run on gas while the electric additional heater runs too, though the additional heater may cut out on its own to guard against overheating.

Below +8°C outside, fit the optional winter covers to shield the unit from the worst of the cold air, making sure they're properly fastened on. They also need to be on whenever you're driving, since EU Type Approval classes them as an external projection - so it's no extra effort to leave them fitted while the vehicle's laid up for winter too.

Climate class SN (which Dometic calls 'Extended Temperate') means the fridge is designed to work reliably when the air temperature is from +10°C up to +32°C (taken at the bottom vent grille, outside the vehicle).

In a hot summer the outside temperature often reaches about 32°C - the top of the fridge's rated range - and once it climbs higher, the temperature inside the fridge will inevitably rise. An absorption fridge needs a heat source to move its refrigerant around the cooling unit (which is why it can run on 12V, 230V or gas), so it has to get rid of the heat from its power source as well as the heat drawn out of the food compartment.

To help it in hot weather: park where the fridge vents get as much shade as possible during the day; unclip the outside vent grilles to improve airflow; and if you regularly travel somewhere hot, consider having a ventilator kit (a fan fitted behind the fridge) installed to boost the airflow - Dometic lists these among its accessories.

Dometic's 2023 'New for old - simply swap' guide covers both its absorption and compressor fridges, showing which current models replace older ones. It's available from the catalogues section of Dometic's website.

Check the fuse in the mains supply and replace it if it has blown, and make sure the vehicle is actually plugged into a mains supply. If both are fine, the AC heating element may have failed - that needs an authorised Dometic service centre.

Possible causes, and what to do: the vehicle's own fuse has blown - replace it (see the vehicle's handbook); the vehicle battery is flat - test it and recharge it; the ignition is off - switch it on. If the fuse in the fridge's DC cable has blown (the fuse on the relay) or the DC heating element has failed, contact an authorised Dometic service centre.

Check the gas cylinder isn't empty (change it if it is) and that the gas valve is turned on. If air has got into the gas pipe, turn the fridge off and on again, repeating this three or four times if needed; if a gas hob or cooker is fitted, switch that on, then try the fridge again if needed.

The mains voltage is too low. The fridge switches back to mains by itself once the supply voltage recovers.

Work through the likely causes: the cooling unit isn't getting enough air - make sure the outside vent grilles aren't blocked; the evaporator has iced up - check the door shuts properly and the seal is seated and undamaged, then defrost the fridge; the temperature setting is too warm - turn it to a colder setting; it's very hot outside - take the vent grille off for a while so hot air can escape faster; too much food, or too much warm food, went in at once - take some out, and let warm food cool before putting it back; the fridge was only switched on recently - give it four to five hours, then recheck the temperature.

Empty the water system completely: leave both the fresh and waste tank drain taps open, along with every internal tap, and keep the pump running until nothing more comes through. If you're expecting particularly hard frost, it's also worth taking out the water filter on the pump's outlet side and clearing it of water while you're at it - a handy moment to give it a clean before next season too.

Pull the sink plugs so air can get into the system, flush the waste tank thoroughly to shift any debris, finish with a mild disinfectant flush, and leave the drain tap open.