Dave/Simon,
This is as ironic as it gets, picked up your replys this morning and went to wash a bowl and hey presto no hot water and behold the 937 is displaying the F81/F91 faults again.
Dave I beleive the fix of new pcb/ntc/pump was around April. Since thenthis is my second trip. I...
Hi I also have a vaillant 937, works quite well for me.........apart from the F81 and F91 errors....called vaillant round and they changed a number of parts and took them 3 or so visits (to be polite first 2 visits were by less experienced engineers). Since then (been couple of months) its been...