Now the OP has confirmed its a cable duct then of course its a Turbomax 824 style.
OP you can see what the differential temperature across the plate HE is and if much more than about 20 C then its probably blocked and causing your problem.
As I said before cleaning the plate HE is a DIYable job but not one of the easiest.
Tony
OP you can see what the differential temperature across the plate HE is and if much more than about 20 C then its probably blocked and causing your problem.
As I said before cleaning the plate HE is a DIYable job but not one of the easiest.
Tony