Heaters only half working

[zooma]

Hiya My Heater on my H Reg K10 is hot on windscreen and legs but when switched to facing the seats its very cold. Is this just the switch at the back of the heater failing or is it Head Gasket? or thermostat? Oil & water OK both top and bottom Rad pipes are Hot. Got the fan to turn on with a paperclip in the sensor to check it turns as I'm yet to see it activate on its own, car temp only ever goes just above the C...... Any tips for checking anything else? Thanks in advance.

 

[zooma]

Its OK I've found a good post on this its supposed to be like it by design. Which makes sense as I remember constantly having the toasted toes many years ago and never wanting to get out the car . Best heaters ever!