I've turned my Vaillant Turbomax boiler onto summer mode but when I open a tap the system fires up and stays that way and the flue outside is like it is during the winter when the central heating system is on. the only way I can stop this is to switch the boiler off then on again and hope nobody uses a tap in the house. any ideas why, it usually only fires up now and again during the summer.

Michelle, June 2008

thanks for your help, got an engineer coming out tomorrow.

Michelle, June 2008

flow switch, not so bad, pcb can be expensive!

safer to get it looked at by a qualified engineer

T, June 2008

there's heat coming from it constantly and it's noisy.
if it a problem with the flow sensor or pcb is it expensive to get fixed?

Michelle, June 2008

either a problem with the flow sensor or pcb I would think (unless you got a leak or a dripping tap somewhere)

what you mean the flue is like it is in the winter?

T, June 2008