Eberspacher D4 Heater only runs for a short period. I've checked everything...

[David2452]

Guys,
Once resolved how could I ensure that the fault doesn't repeat? Does my installation sound reasonable? If it is the problem is ECU failure just bad luck?

(There are two permanent vents and one closing one (although I'm yet to close it.) There's a total of 3.5 meters of ducting and two "Y" pieces to distribute to the vents. All the ducting is the same 75mm diameter. There are two 90 degree curves made with the ducting (not an elbow piece.) The ducting is insulated.)

The ducting install is not the issue from your description, though if you get overheats with the install it may be worth removing the first six inches or so of insulation, but even that should not really be needed except with some later heaters.