Advertisement Hide AdAdvertisement Hide AdWhen the weather did turn, 59% reported their radiators didn’t heat up properly, with repairs costing an average of £330. Three weeks before winter: Check the settings on your heating and hot water timer. If the heating is on but the top of the radiator is cold, it's time to bleed them. One week before winter: Taking care of draughts before the temperatures drop means you'll stay warmer and save on heating costs once winter sets in. Taking care of draughts before the temperatures drop means you'll stay warmer and save on heating costs once winter sets in.