hot water problems Potterton Combi 80

[Fat_Freddys_Cat]

Hi wondering if someone can help.
we have a Potterton Combi 80 (gas)

The Hot water only works upstairs where the boiler is situated and you have to turn the taps on and off 3-4 times very quickly to get hw when CH off. When Ch on hot water no problem but is at much lower temp.

nothing has been done to the system except a new heat exchanger and PCB about a year ago


any help would be much appreciated

cheers

 

[corgiman]

possibly the flow switch needs replacing

or have you noticed if your water pressure has been reduced lately?

 

[Agile]

Yes most likely the flow switch shaft is tight or the switch is out of adjustment or the diaphragm is failed. I would put my bet on the latter from this description although its pretty unusual!

Tony

 

[ChrisR]

If you lift the front off the boiler (2 screws) you can see the printed circuit board. When you turn a HW tap on, a red light on the pcb, should illuminate. Gives a very good clue, so does it do that?

 

[Fat_Freddys_Cat]

The red light only comes on when a hot tap upstairs has been turned on really quickly and the boiler kicks in, if you turn the taps on normally you get no light and only cold water.

Where is the flow switch and how do i adjust it ? i havent noticed a drop in pressure lately.

Thanks in advance

Cheers