Truma W407H warning code

PhilDK replied on 15/04/2023 18:17

PhilDK

Posted on 15/04/2023 18:17

Hello,
I just noticed that I get the W407H warning on my CP+ panel for my for my Truma combi boiler.
Researching this on the web indicated that this happens when the 240V supply feeding the caravan is disconnected when the source for the boiler is on electric.

In my case the 240V supply feed was connected and running in the caravan but I noticed that if I turn the heating/hot water off, after heating the boiler, on the caravan power panel under the seat then the warning is displayed. If I turn the heating/hot water on the power panel the the warning clears.

Is this normal or have I a problem with the system.

Thanks you for any guidance.
Phil.

4 replies

SteveL replied on 15/04/2023 19:40

Member

SteveL

Motorhomer from Nottinghamshire

Posted on 15/04/2023 19:40

Sounds like the power panel you refer to just isolates the 240 volt to the Truma. We had something similar on the Alde boiler in our Bailey Cadiz. You would normally just turn the heating / water heating off on the Truma control panel and leave the power switch on, thus avoiding the code warning. The only use I could see for the switch was if you wanted to isolate the boiler to work on, as it meant the 240 volt could be maintained to the rest of the van.

1 person likes this

PhilDK replied on 15/04/2023 19:57

Member

PhilDK

Caravanner from Hampshire

Posted on 15/04/2023 19:40 by SteveL

Sounds like the power panel you refer to just isolates the 240 volt to the Truma. We had something similar on the Alde boiler in our Bailey Cadiz. You would normally just turn the heating / water heating off on the Truma control panel and leave the power switch on, thus avoiding the code warning. The only use I could see for the switch was if you wanted to isolate the boiler to work on, as it meant the 240 volt could be maintained to the rest of the van.

Posted on 15/04/2023 19:57

Thanks for the advice SteveL
Is a bit strange that when I prime the boiler, I have the heating/hot water off on the power panel under the seat and also on the CP+ controller.
The power to the caravan is on and the pump activated to pull the water into the boiler from the aqua roll.

Under this scenario i do not get the warning.

Phil.

SteveL replied on 15/04/2023 22:57

Member

SteveL

Motorhomer from Nottinghamshire

Posted on 15/04/2023 19:57 by PhilDK

Thanks for the advice SteveL
Is a bit strange that when I prime the boiler, I have the heating/hot water off on the power panel under the seat and also on the CP+ controller.
The power to the caravan is on and the pump activated to pull the water into the boiler from the aqua roll.

Under this scenario i do not get the warning.

Phil.

Posted on 15/04/2023 22:57

The Truma control panel is only reacting to wether there is 240 volt power to the boiler. If the heating and water are off on the Truma panel, then you won’t get an error if the power is turned off elsewhere. Similarly if you have selected to run on gas only, you won’t get the error. On our MH I don’t have a separate switch for the Truma, however just occasionally I trip the power ( prior to disconnecting from EHU) forgetting the heating is still on. Under those circumstance I get the warning you describe.

PhilDK replied on 16/04/2023 14:53

Member

PhilDK

Caravanner from Hampshire

Posted on 15/04/2023 22:57 by SteveL

The Truma control panel is only reacting to wether there is 240 volt power to the boiler. If the heating and water are off on the Truma panel, then you won’t get an error if the power is turned off elsewhere. Similarly if you have selected to run on gas only, you won’t get the error. On our MH I don’t have a separate switch for the Truma, however just occasionally I trip the power ( prior to disconnecting from EHU) forgetting the heating is still on. Under those circumstance I get the warning you describe.

Posted on 16/04/2023 14:53

Thanks SteveL.
I understand the reason now.

Regards,

Phil.