Digital TV – Electrical interference

Electrical interference can cause picture break-up (pixelation) or freezing, or clicking sounds.

The interference can be caused by anything powered by electricity, such as domestic appliances, switches and computers (in your home or a near neighbour's). The most common cause is a faulty boiler or central heating thermostat, which can lead to regular bursts of interference (e.g. for 10 seconds every 20 minutes).

Sometimes, high-voltage electrical equipment outside your home can cause interference.

An unusual colour effect on the TV screen may be caused by the magnets inside a hi-fi speaker, so don't put speakers on or near the TV.

• To work out what is causing the interference, leave the TV on and switch off or disconnect your electrical appliances one at a time to see if it stops. You may need to repair or replace a faulty appliance or thermostat.
• If you're getting an unusual colour effect on the screen, make sure there are no hi-fi speakers on or near the TV.
• If you think high-voltage electrical equipment outside your home may be causing the interference, you could ask Ofcom to investigate - but please note that Ofcom may charge a fee for this. See the Ofcom page about TV or radio interference or reception problems for more information.