I’m an engineer – here’s the one job you MUST do after switching off heating for summer to avoid a nasty winter suprise

MOST of us don’t give much thought to switching off our heating for summer - it’s just obvious when it needs to happen. Warmer weather, lower bills, decision made. But engineers say there’s one simple task you must carry out after the switch-off - and it's something hardly anyone realises. By completing this job, you'll...