Glow worm Betacom4 30c

[Cramer]

My boiler is 4 years old , the water keeps going hot and cold intermittent , had plumber out and he couldn’t work out what was wrong with it
As no Fault codes he managed to reduce the flow of water and it’s worked fine since up until today , I was in the shower it started again ! The hot tap pic on the boiler wasn’t flashing . Turned shower off and restarted the boiler and it worked again
Just don’t want to keep having cold showers !
Any advice ?

 

[CountryFan]

Sounds like diverter valve issue, plate heat exchanger or perhaps something else. Get a different engineer or Glow worm fixed price repair, the former is likely cheaper though