lack of hot water in the eening

we have a pusacoil 2000 in our flat. In the last week or so we have been experiencing a lack of hot water in the evening time from about 8pm onwards. This never used to be a problem as my husband and i could both have showers during the day and run the wshing machine and still have enough hot water to last us through the evening. My husband has had a look at the user istructions and the lights on the control pannel seem to be indicating that nothing is wrong. Does anybody have any idea why we are running out of hot water in the evenings.

Probably DHW sensor failure, but that's just a guess.

Cheers, MIke

If your not getting hot water in the afternoon/evening but is ok in the morning, then your boost element may be gone.

Yes, but only if the boost had been left on 24/7 in the first place. Then, like you say, the element burned out.

This set of symptoms would also arise if the boost was originally left ON all the time (incorrectly), then somebody noticed it was ON and turned it OFF.