Vaillant turbomax that has heating on all the time even when stat is off programmer disconected.

Tony, June 2009

if its the turbomax plus version then the problem sounds like a diverter valve. if you have the warmstart ( hot water pre- heat ) turned on then as the boiler tries to heat up the hot water store its sending down the cental heating. on fix is to replace the diverter valve. they retail at about £130 +VAT

vaillant chris, June 2009