Truma boiler (5 year old) - HELP

Garydoyle63

We have a second hand motorhome with a truma boiler (5 yr old 13,000 miles). We are continually having problems and as it's under warranty have returned it several times. The latest, the boiler was working fine. Switched it off one night. Following day no
lights on the dial and stopped working.

just wondering am I doing something really wrong or has anyone else had these issues or know how to solve them?

Many thanks