Heaters going cold

Went out this afternoon heaters set at 21centigrade drove 30 miles really warm all the time,stopped went shopping came back 1/2 an hour later and they didn't warm up at all engine temp gauge normal,been playing up some time now A/C not working at all,could it be a loose wire or sensor,would a hawk eye pick it up?
Chris

Chris, I had a coolant leak in mine and once the levels got low the heater stopped blowing hot but the gauges read nominal. Worth a look before calling the coastguard .

Matt

Thanks Matt,I will check the coolant tomorrow, got to be something simple
Chris