Having trouble with climate control. Heater will not work. Heater tap appears to work but no response with warm air. Any ideas?

im guessing an E2 error. the blend door motor.

I thought mine might have been the E2 error, however after doing the diagnostics on the climate control no errors came up.

So after that I flushed out the heater core.
I did this by removing the heater tap, disconnecting the other heater hose and connecting an adaptor to the exit heater hose. The adaptor I made up to connect a water hose and a air line up together. Once in place I turned on the water and periodically blasted compressed air through the heater core.

Secondly I found that the heater tap that I had installed only a few months ago was not opening fully(I could only tell once I removed it). I bent the actuating lever slightly so it is now fully open with no vacuum attached. After replacing everything I then refilled the cooling system and ran car up to operating temp. inserting a digital thermometer into the face level air vents with the CC set to 32deg, air temp reached 52 degrees, gotta be happy with that. I then lowered the CC set point to 16deg and the air temp at the air vents dropped down to 14 degrees.

check if all your vacume lines are intact under the bonnet

For heat the heater tap doesn't require vacuum, it is normally open without vacuum. Vacuum is only applied to close the tap when no heat is required. Therefore a vacuum problem would not affect heat, only selecting vent positons and/or cold air.

maybe not for the heater tap but loss of vacume or lack of it could effect internal controls of your heating system.

once had a vacume line rub through in my fokes DF LTD caused it to run a little rough and heater not to work. it was a short little hose about 3 inches long with a bend in it close to the firewall if i can remember.