My hot water has been intermittent for a while now it's become worse.
The heating is working fine.
I have looked in vain for a repair manual as opposed to instructions and operations manuals but cannot find one. Can anyone help here?
I suspect it could be the flow switch or filter as the boiler does not even attempt to light. At this stage I don't think it's the diverter valve.
Can anyone suggest the best SEQUENTIAL check list.

Michael, February 2018

First search result:

https://www.biasi.co.uk/assets/public/user_manual/24/Riva%20Compact_User%20and%20Installation.pdf

Third search result:

https://www.biasi.co.uk/assets/public/installer_literature/34/Riva%20Compact_Service%20Manual.pdf

Anon, February 2018