Truma Hot Water Problem

From what you describe it almost sounds as if the tank is emptying itself. Have you checked there is no sign of water escaping under the van? Does the pump continue to run for longer than normal? Do you know what sort of pump you have, is it internal to the tank or a stand alone pump outside the tank. 

David

Seems like the seals in the pump are gone and water is running back out to the Aquroll.   To test get it filled up. Swithch off the pump and then pull out the water connector on the side of the caravan.  If water tuns out you have the cause.    

I do not have a problem with the water on my caravan, but water will escape from the side of the caravan when the pump is removed .... 🤔

Thank you for your replies: I hope this gives some further information. It is a submersible Reich water pump which is brand new. No sign of any water leaking from under the motorhome. My latest thought is that water is running back from the boiler to the water pump but why should it suddenly start?

I think this is quite a common problem on motorhomes with submersible pumps. My second Bailey has one and I often have to bleed the system which I never did with my previous Bailey which had and external to the tank pump. What I do is release the pipe going into the tank at the top which feeds the water system. See photograph below (right click on it to open a larger version in a new tab) If it is the same sort of fitting as mine it as a John Guest snap fitting which is easy enough to take apart but make sure you have a towel handy to collect any escaping water. I ease the joint apart and as soon as water starts to escape I push it back together and this usually cures the air lock. 

David

Update for anyone who comes to these posts in future. I have solved it by putting a non return valve in the cold water feed to the Truma. It seems weird that although the installation instructions show that with a submersible pump a NR valve should be installed, ours worked fine until I had to replace the water pump.

In summary, if you can't get hot water to get rid of the air locks after winter, check if the non return valve is operating properly.

Useful tip, thanks. Talking of hot water systems.... hopefully one day somebody will solve the mysterious workings of the Truma W 255 H error code.🤔

Bill, it occurs when the 12v supply is removed from the unit (even turning of main MH control panel) before its been properly/fully switched off.

different (but similar) errors occur when the gas is turned off or the EHU removed before closing down the Combi...

always turn the Combi fully OFF (hold button for 5 secs or so until OFF appears in the screen) before closing down all other power sources.

from the Truma web site...

"Warning W 255 H appears in the display of the CP plus panel – what should I do?

The heater does not have 12 Volt power supply or there is no connection between the heater and the CP plus control panel.

The power supply to the heater may have been interrupted by switching off the vehicle control panel (not the Truma heater control panel).

The control panel is used to control all other functions in the vehicle and it also switches the power supply for the consumers in your vehicle on or off.

In this case turn on the control panel in your caravan to reestablish power supply for the heater.
Once the power supply is guaranteed and the warning is still present, check the cable connection between the heater control panel and the heater."

Thanks, do you ever get ‘App’ displayed rather than ‘off’ when turning off the control unit? I use the Truma App for iNet and remote control unit in the van.

i dont use the app, but i guess thays something to do with it. perhaps it just means under control of the 'app'?.....

ive seen so many issues raised with the latest remote control, 'integrated solutions' like Command etc that im happy to push a button for 5 seconds.