As I drove a trip in my newly acquired coupe, I ran into a thunderstorm as usual. Quickly the front screen misted but starting the blower and opening the handle to "hot" had no effect. At home I took off the large hose between the blower and heater and found that the blower works. I controlled that all the settings on the regulators are as per book, and could see into the hole for the hose that the flaps are working. Only fault I found was that the foam on the flap had fallen off and now blocked the hole into the car. With this removed I think I can feel a sligtly breeze at the windscreen, but I suppose insufficient to handle a Danish summer. Should the heating system be efficient and if so, are there any common fault ? I suppose that the air will goto into tunnels in the body and from there enter the nozzles at the screen ? I could also see a larger springloaded flap opening into the heater. I could not see anything in fact actuating this, so is this only to let pressure escape from the car when doors are closed
The heaters are efficient when new but the heater matrix becomes silted up and the compilcated linkages on the heater box can seize or become out of adjustment. The hot water valve can also block/seize
The only way to test to properly is to remove the box complete and descale/renew the matrix and replace foam sealings and readjust the flaps so that they operate in the correct order
Yes, you are quite right about matrix can be blocked. However I am puzzled about no air coming into the car. The matrix, should it be blocked internally, can be a winter project. If I could just get some air through the system, I can keep the screen clear. All the linkage is working and adjusted according to the book, and the blower delivers the air on the input side. So if it should be efficient, something must block the air-passage somewhere.