Hello, has anyone ever had TV signal interference caused by their boiler thermostat and if so how did they fix it?

Cheers.

Th eonly thing I can think of is that sparking is sending out an RF signal. You should be able to get rid of this by replacing the thermostat. Also, putting a large unpolarized capacitor (or two back-to-back polarized capacitors with like poles connected) across the contacts will reduce the amount of RF that's emitted.

You can definantly see a difference when on or off? Or all the time?