I took my '93 LSE up to Aberdeen last weekend, and the drive was ruined by the fact that my heaters don't work.

I had two jackets, a hat and gloves on, but was still freezing!

The blowers work on full, but there is just no hot air. The car drives fine with no overheating and I've bled the coolant etc. Radiator was replaced recently so it's not that.

Could the heater matrix be blocked or should I start somewhere else first?

Check that water is circulating through the heater matrix by seeing if both pipes that feed the heater are hot. If not try bleeding the matrix by removing on pipe and see if any air comes out Best done engine cold with expansion tank cap off.
If that is not the problem then probably blend motors not working.

No blend motors on the Classic. I had this on my LSE. If rest of cooling system is fine then the heater matrix is blocked/airlocked.

Did the heater work before the new rad? if so it's prob an airlock, search on here, there's loads of threads on removing airlocks.

If not some gunge may have found it's way into the matrix from rad change.

You didn't by any chance use something like K seal or Wonderweld to stop the old rad leaking did you?. . . cos that would block the matrix.

TRy disconnecting both pipes to the heater on top of the RH rocker cover and flush it through both ways with a hose. I did that with mine and it washed a fair amount of silt, corrosion & crap out. Think mine needs doing again.

Good luck.

Alastair

Air bubble, I'll betcha. Burp it at the heater line filler, which is at the top of the system. Sometimes it takes a couple burps and fills to get things full.

Also you can get one of them pre heaters, stick a timer on it (if you use it to commute the same time of day) for 20mins before you use it, and the car will start first time and you will also get instant heat, so it will defrost windows a lot faster