Hot water issue - Potterton ProMax Combi 28 HE Plus

[Pheneyboy]

Hi all,

Hoping someone will be able to help me please. I have a Potterton ProMax Combi 28 HE Plus, and recently the hot water pressure seems to have dropped, I can get hot water on my taps but only when the demand is for hot water only, as soon as you mix it with cold water the hot water light in the boiler goes out, I’m assuming because the pressure drops when the cold is opened. The kitchen tap did have intermittent hot water but it now works on full hot because I have removed the aerator from the tap, as soon as I put it back in, no hot water!

This situation is the same upstairs, I can run a bath with only hot water fine, but if I try and use the mixer shower, no hot water again.

The central heating works fine it’s just the hot water from the taps that is having this issue. So far I have cleaned the heat exchange plate, got the water board to check the water pressure into my house (they improved it on their visit but it was fine anyway, over 25 litres a minute), checked the system for air locks and cleaned out the pipes and checked for blockages.

I’ve got a few things to try next but wondered if anyone had seen something like this before please? I don’t want to spend money replacing parts that don’t need replacing.

Thanks all!

 

[cross thread]

Flow restrict or blocked or inlet water tap not fully open

 

[Pheneyboy]

The water Inlet seems to be fully open. My next thought was to try replacing the flow switch, is that the same as the flow restrictor or is that different?

Thanks

 

[Deleted member 267285]

Don’t chuck parts at it. Sounds like a blockage at the cold inlet to the boiler.

 

[cross thread]

Flow restrictor is a part in the inlet flow switch. In the inlet isolation valve is a gauze filter accessed by the front cap or by removing the built in filling valve if fitted.

 

[Pheneyboy]

I checked the flow restrictor and the inlet valve, it seems to be clear there wasn’t any grime or anything blocking it so it doesn’t seem to be that. Any other ideas please? Thanks