Tim did you flush the matrix, My wife had a Renault 5 once & the heart was pathetic. A bit min blast through with garden hose & the sludge was out and it worked.
Good idea, but in my case it's not the heater matrix that's the problem, it' the poxy heater fan. The motor itself is pretty weak and the fan is a very poor design, just radial blades. The box it's sat in has got no ducting at all as such, just the flaps either side and two pipes at the front leading up to the windscreen vents.
With the hood up, it gets very nice and warm within a few minutes, but top down on a cold day you're lucky to get any heat at all out of it, the fan just can't shift enough air. With the side flaps open you might get a bit of warmth on the legs, but then the screen mists or freezes up. Driving in the winter when it's a bit damp/foggy/drizzly I tend to have the hood up more than I strictly need to. Crisp, clear days aren't so much of a problem as you just wrap up warm and enjoy it.
