How to Use the Truma CP Plus Control Panel (Heating + Hot Water)
The Truma CP Plus is the control panel used to operate and monitor your Truma system (heating and hot water) in many Mars vans. This guide covers the everyday basics: turning it on, setting cabin temp, setting hot water, choosing power modes, using the fan, and understanding warnings.
Quick Controls (Know This First)
- Turn ON/OFF: Press and hold the rotary push button for more than 3 seconds.
- Scroll & adjust: Turn the knob left/right to move through menus and change values.
- Confirm: Press the knob to save a value / enter the setting level.
- Go back: Press the Back button to cancel and return (previous values remain).
Set Your Cabin Temperature (Heating)
- Select the room temperature (heating) icon on the top menu line.
- Press the knob to enter settings.
- Turn the knob to set your desired temperature.
- Press the knob to confirm.
Typical adjustable range is 5–30°C (or 40–86°F, depending on unit settings). The heating/furnace icon may flash while the system is heating up to your set temperature.
Tip: If you’re on the stand-by screen, you can usually adjust temperature quickly by turning the knob, then pressing to confirm.
Set Hot Water Temperature (Boiler)
- Select the hot water (boiler) icon.
- Press the knob to enter settings.
- Select the water mode and press to confirm.
- eco = 40°C (104°F)
- hot = 60°C (140°F)
- boost = rapid heat-up (boiler priority for a short period), then returns to normal operation.
The boiler icon may flash while the water is heating to your selected setting.
Select Energy Mode (Gas / Electric / Mix)
- Select the energy icon.
- Press the knob to enter settings.
- Choose your power mode and press to confirm.
- LP gas = Gas only
- MIX 1 = 850W electric + gas
- MIX 2 = 1700W electric + gas
- EL 1 = 900W electric
- EL 2 = 1800W electric
Note: Electric and mixed modes only apply to systems fitted with electric heating elements (e.g., “E” models). If you’re not on mains/shore power, use LP gas.
Fan Speed (Airflow)
- Select the fan icon.
- Press the knob to enter settings.
- Choose a fan mode and press to confirm.
- OFF (only available when heating is off)
- VENT (circulating air with heating off; usually adjustable in multiple steps)
- ECO (low fan speed)
- HIGH (high fan speed)
- BOOST (fast room heating under certain conditions)
Timer (Time Switch)
Safety: If the timer is enabled, it can start the heater automatically. Never use the timer when the van is parked in an enclosed space (like a garage).
To set the timer: select the time switch icon (bottom menu line), press to enter settings, then set the programmed times and confirm. The timer typically requires the clock to be set first.
Set the Clock (Do This After Power Loss)
- Select the Set clock icon (bottom menu line).
- Set the hour and press to confirm.
- Set the minutes and press to confirm.
If your power has been disconnected, the clock may need to be set again before the timer works.
What the Mains Power Icon Means
If you see the mains/plug icon, it indicates mains (shore) power is available to the system. In Australia this generally means you’re connected to 240V supply.
Warnings & Fault Codes (W / E)
- Warning (W + code): Something is out of range, but the system may still run.
- Error (E + code): A fault has stopped operation. Fix the cause, then acknowledge/reset on the panel.
If you’re unsure what a code means, take a photo of the screen and contact Mars Service with the code displayed.
Cleaning the Control Panel
Wipe the front of the CP Plus with a soft, non-abrasive cloth lightly moistened with water.
If needed, use a neutral soap solution. Avoid harsh chemicals.