Alpha CB28 - Hot water confusion

[UnusualCapybara]

Hi All,

I have just moved into a new property which has an Alpha CB28 boiler which is causing me some confusion. I have one main question to other owners of the CB28 or CB24 which will hopefully lead me to identifying a fault.. or not

Should there be hot water on demand even at times when the heating timer is not active?

Currently this seems a little bit hit and miss with on demand hot water sometimes but other times leave me with stone cold water flow which is only corrected by putting the heating on.

My brain tells me this isnt quite right but just wanted to double check.

 

[Agile]

Of course there should be DHW at any time.

You apparently have either a failing diverter valve or an intermittent DHW flow switch ( or BOTH ! ).

Tony