Any Valliant experts out there? TurboMax 824

[saxd]

Hi
Is it sludge, a dodgy DV or scale maybe - any help appreciated
Model - TurboMax 824E
Every morning F22 error = no water in system
Reset and run HW , yellow light ON and temp then shoots up to 115 and back down to 60 with equivalent popping, hissing, banging and yellow light goes off (igniton)
Reset again upto 90 with more gurgling etc, back to 60 but cold water
Reset again works ok

Chemical flush & replacement DV 2 weeks before problems started happening
1 corgi registerd plumber says i need a new bolier, but i'd like to get 6 more months out of this one if possible

any ideas? - thx all , great site etc

 

[Mozza00]

Says that problem is either - No water in appliance, pump cable defective, pump
blocked or defective, pump output too low.

Have you checked pump for blockage or sludge?