Hi,

I have a Saunier Duval Thelia 23, the central heating is working fine,=20
however the hot water is not.=20

When in Central Heating & Hot Water mode, the HW is almost
at mains temp, slightly above, when in HW only it is the same.=20
The HW temp control has no effect at all.

However putting it into HW mode and putting the CH temp=20
control to halfway, (usually is at 1/4)you get HW bouncing between=20
cold and hot and very hot radiators. The HW temp control has no
effect in any mode. Using it in the unorthadox CH burning hot it
makes a banging noise upon providing HW then gets cold then
repeats.

Any ideas on how I can fix this, don't want to run the gambit of
=A350 call out fee's, getting a =A3300 repair bill and all. After =
installing
a doubleglazed window for about 10% of the cost 3 quotes wanted
i'm not in the mood for calling the professionals

Thanks for any advice