We have an old Baxi Bermuda back boiler which, when switching off the
cnetral heating (and to a lesser extent, the hot water) causes interference
on the digital TV picture such that the TV loses the signal until the
heating is switched off. During the winter, with the central heating on,
this process happens every few minutes. With analogue TV this was an
inconvenience since all that happened to the TV was a stripy line for a few
seconds. With Freeview, the whole picture freezes, breaks up and disappears.

Does anyone know whether the thermostat can be replaced with a more modern
one that won't cause the interferrence or, failing that, can one obtain some
sort of interferrence suppressor?

Cheers,

David