heater going hot and cold

[frosty1]

noticed today when I set the heater after 5 to 10 minuits it cools down any help please

[KEN33Y]

Hi Brian, can you give any more information to work with. Not having the full information its difficult to make an accurate diagnosis it could be a number of things. On an older car I would have suggested the thermostat was stuck open therefore, not allowing the engine to heat the water fully

[frosty1]

Thanks Kenny for your replay

Got a 04 x type diesel 2.0 green cream leather upholstery yes i know thats real no help but i just like saying it.

Ok last 2 or 3 days setting heater at about 22 it has worked ok nice and worm and then it starts blowing cool, i dont have the A/C on as it needs charging so its not on auto as recomended. If i do alter the temp it will warm up again and then cool again 

hope you can help thanks Brian