Hot water comes and goes!?
Vaillant VCW-Sine18 T3WFH Lights but then goes off after 5 Min?
Vaillant 828E - no hot water?
can i replace my Potterton EP2 2 way programmer with a Center EHE0200361 RF?
Vaillant F22 fault?
how do I rectify the fault as detailed below?