HELP please - Potterton Powermax HE lockout

[combi hater]

Hi,

I was called to a friend tonight who came home from hols to a cold house.

Roomstat is turned up, controls all calling for DHW & CH but lockout showing A15.

Before I got to her she had topped up the pressure so i don't know what it was. She topped it up to 2bar and it worked for a while with the pressure climbing then cut out with too high pressure showing error E01 (not it user manual).

I released some system pressure and dropped it to 1.5bar.

Again it wouldn't fire up and showed lockout A15 (I reset it every time).

In the end I thought to turn on hot tap before the reset. This time it fired and pressure climbed well, plenty of hot water but no CH. Left the hot tap running for ten mins no CH then digital display on boiler showed pressure dropping before another A15 lockout.

I have bled the rads if this would make any difference or not (no air anyway).

Does this sound a familiar problem to anyone?

Many thanks.

 

[corgigazza]

Expansion vessel will require recharging(do search), rads will not work until thermal store is heated up, 10-15 mins, will also have a prv leaking that will need servicing/replacing


This is a very complicated combi and may require an engineers visit

 

[combi hater]

All sorted thanks.

She rang the housebuilder (national firm) to try for repair under warranty and to amazement they got the Baxi/Potterton repair man to ring her. He practically diagnosed it over the phone as the pressure sensor switch.

Took him a couple of mins the next day to change it and it was running perfect.