Your heater matrix might have packed in.
Not too sure but thats what i would have thought...
'Heater' is underneath the plasticky bit between the bonnet and the windscreen. There will be a piece of plastic and a pollen filter on top of it.
When I say heater, I'm not sure if it takes heat from the engine, and it's a 'blower'.
If not, check the fuse for the heating element , and not the blower.
Another though, change the pollen filter, what with all this mighty cold weather, it's difficult to warm up when the pollen filter is blocked up. I think.
The heaters on my polo used to be shocking at times, i had a little tinker with all the heater stuff and it just started working again, not sure what i done, but the heaters suddenly got good.
if you can mate strip it down then rebuild it could just need a little attention and something might have come loose.
if that fails i have a great halogen heater which will plug into your power inverter and will warm your car
Can you hear the fan going when you turn them on, ie, is it the heat isnt getting to the heater matrix, or the heat just its being blown from the matrix in to the car?
Have you noticed any water leaks?
Is the thermostat in or out at the moment?
what does the temp gauage say inside ther car tony, you could have a problem with you cylinder head gasket.
how much water/ ainti freeze is in the engine, might have an air blockage, or a blocked heater matrix, if you can see 2 small water pipes going into the car, disconect them and using a hose pipe flush the matrix out (hose pipe on one of the pipes going into the car) if no water comes out then youll have a blocked heater matrix
this might sound daft but you have got the heater control in the car set to hot?
whilst the engine is a normal running temperature feel the water pipes under the bonnet if one of the pipes is a LOT cooler than the others then youl have an air blockage, for this youll need to bleed the water system on your car
has the engine got bleed valves? if so when the engine is cold and NOT running undo/open these and see if any air comes out
yeah i would do what rachael said and flush the matrix out.If water comes out all browny and dirty colour the matrix is more than likely blocked.I do this regularly in work with cars that have same problem as you
I never knew this is how it worked.
I have problems with the centre blowers, they seem to take longer than the side ones