There is quite often a thermal cutoff on the heater. Try searching for the tech manual for the type of heater on the web to find the location of the cutoff switch.
It's normally a slightly hidden button on the side of the unit
Discounted Insurance Quotes for UKCampsite.co.uk visitors! Up to 12.5% off!
if the fan is blowing and cold air is coming out and all fuses and trips are ok then i suspect the element.Check supply to the element with a meter and make sure youhave a supply.240 volt ac should be present at the element terminals
------------- i dont sell cheap tat.I sell tat cheap
you need to put your hand down the back of the heater (usually inside a cupboard) on the left hand side, you will feel a slight dimple on the panel around about knee height press that, it should start up warm again then