I was called out to inspect a Bristan electric shower unit as the control knob was not operating normally and the water temperature changes seemed to be erratic to the users. This unit had nice blue lights on the front control panel.
I found a blocked fine water filter in the flexible hose supply at the shower end. Why it is there I do not know. That was the cause of the trouble, it was partially blocked, with what looked like fine sand and scale. There is also a mains in water filter in the cold supply hidden underneath the shower. That was perfectly clear, so the sediment and scale I discovered were not coming from the mains water supply.
After removing the flexible hose I ran the shower unit and loads of dirt came out of the unit. The heating tank is producing scale and the element sheath is deteriorating I think, and that produces the fine dark coloured sand like particles
So if you are called to look at one of these shower units it is best to check the water filters first before taking off the cover of the unit.
Bye,
Z.
