Interfernce suppression?

I have a Glo worm Ultimate central Heating boiler which is causing interference to digital tv and dab radio reception.

The interference occurs at any time when a demand is placed on the boiler the hiss/crackle can be heard from the boiler at the same time as the inteference occurs, I have tried ferrite rings on the arial leads and - no change. there is no suppressor shown on the spareparts list.

Q1 Is this the thermostat if so does it require replacement?

Q2 if not the thermostat what is it?

Q3 can a suppressor be fitted if so which one?

Glo worm help is worse than useless they do not seem interested at all other that to advertise new systems!

The interference is driving me NUTS!