Truma Combi 4 not working

[w1ntersun]

Hi, He in sunny Spain and the Truma isn,t working. We have an Auto trail Savannah ec500 and ec480 controller

 

We ran out of gas the other night. Red light came on the control switch.

 

Turned off the heating on the truma control switch and the following morning changed the gas bottle.

 

Switched the fridge off and on to reset the sensor. Fridge OK. Gas ok on gas rings.

 

Came to switch on the heating and no lights appeared. switched Sargent unit off and on to reset and still not working. Sargent said to check fuse 8 and its OK.

 

Any ideas please Richard

 

[Derek Uzzell]

If no LEDs are lit on the heater's control-panel, possible causes are suggested in the trouble-shooting list of the Operating Instructions. These are as follows:-

 

"No LED is shining, the device is switched on and is supplied with operating current.

 

- Automatic restart is blocked, e.g. after a power failure.

- Reset (fault reset) by switching off, waiting 5 seconds and then switching on again.

 

After switching on (winter and summer operation) none of the LEDs are lit.

 

- No operating voltage.

- Check 12 V battery voltage, charge if necessary.

- Check all electrical plug connections.

 

- Device fuse or vehicle fuse defective.

- Check the unit or vehicle fuse and replace if necessary (see fuses).

 

FUSES

The unit’s fuse is located on the electronics under the connection cover. Replace the unit’s fuse only with an identical fuse.

Device fuse: 10 Amp – slow – (T 10 A)"

 

As the heater is apparently 'dead' and the problem seems to be electrical, you really need to begin by checking whether or not 12V power is reaching the unit. If it is not, then the heater obviously won't run. If 12V power is present at the heater, then try replacing the heater's own fuse.

[Rayjsj]

We too have had problems with our Truma Combi 4E on our Savannah, ours was mostly when used on EHU, but the result is the same, Red LED on control knob, and unable to reset the heater. Ours turned out to be a blown fuse on the Truma mains control board. You have to dismantle the Cover and the DC pcb, to get to the AC control pcb. Make sure you unplug your mains cable before trying it. I now carry several spare fuses.

I think that there has been a couple of 'Upgrades' to the control PCB's of these units, I can't say that I am suprised, they are very 'Flakey' ( an electronics term meaning : unreliable and prone to failure).

We are NOT very happy with the unit, even when working it is very noisy on startup, AND we no longer TRUST it. (and always carry a 'Back-up' form of heating) Ray

[w1ntersun]

Hi, Thanks for the suggestions.

 

I have got it working but something is wrong

 

I turn on the truma with the truma control NO lights come on

 

I switch the Sargent control panel off and on and the truma lights up and the boiler fires.

 

I turn the truma off on the truma control and it continues to stay on and work ????

 

I switch the sargent control panel off and on and the truma switches off.

 

Some times it takes several switches for it to work

 

Is it the truma or the sargent at fault

 

Thankfully its warm and sunny here

 

Richard

[Derek Uzzell]

Your heater needs 12V power to operate and, as it won't operate with the Sargent unit switched off, but will operate (albeit oddly) with the Sargent unit switched on, that probably means that the Sargent unit is OK. The fact that the heater continues to operate despite being switched off at the heater's control-switch also suggests that the problem lies with the heater.

 

You could try swapping the heater's 12V fuse, but this sounds more like a pcb-related fault.