Can anyone help when I turn on the cold water in the kitchen or bathroom it will run cold for a few seconds then start to come out hot then after about 20 seconds it will start to run cold for a bit then hot again and just keep doing it. My van is a Bailey Ranger 450/2 from 2000 and I have a truma ultrastore water heater, my guess is that there should be a non return valve somewhere that has packed up, any advice would be a big help.
There are a couple of points that it could be at I'm not to sure where, I'll try to explain what it looks like, from the water inlet there is a T joint that goes to a surge damper one way and to the rest of the van the other, there is then another T joint that goes to the heater one way and on to the rest of the van the other, up toward the heater there is the drain valve then the pipe runs up to the heater and it connected to the heater with a push fit connecter, so my question is which on is the NRV. Thanks in advance.