My Alpha combi boiler has very low water pressure at the DHW hot tap?

you can remove the heat exchanger by turning of your main cold water supply open your hot tap to drain your dhw unscrew the exchanger which is staight forward. then soak in descaler overnight. u can buy the descaler which we use for powerflushing from plumbcentre etc.you can't damage the exchanger taking it out it just pulls off once unsrewed.
ITS NOTHING TO DO WITH YOUR PUMP
AND CHEAP THAN NEW ONE

HI-SPEC PLUMBING.
July 2006

Yes scale is always a problem with domestic hot water heat exchangers. You will not have a machine to clean it so it would be best to change it if you can.

leigh
July 2006

I THINK YOUR PUMP IS GONE

JAS
July 2006