Hi, I’m an Aussie living in Peru, and am finding it difficult to find a plumber/gasfitter (as professionals don’t exist here) to help me with my Junkers tankless hot water system. Everything works fine, the water is very hot, but exactly 5 minutes into a shower, the hot water stops. I then need to shut the tap and start it again, a process which is slightly unpleasant in winter.
Any tips as to the cause and solution would be greatly appreciated by my wife and I.
What model Junkers do you have there and what water flow is running when your shower is working. Some Junkers units have thermostats ( adjustable) and some do not – the model would assist as it seems from your description that the water flow is too low for the heater and it is shutting down due to overheat.