So had problem with the heater where the thermostat would not move and cold air coming through vents at 22d setting , Had both themostats replaced along with a sensor or whatever its called. Took it for a run and all seemed well. Well 24 hrs and problem back, now he said its proberly the Matrix on the drivers side blocked as when he fiddeled around turning knobs etc the heat came through when it was on maximum. Whats involved getting to the matrix and how to unblock is my question, would appreciate you comments , Thanks.

You should be able to flush matrix from the pipes into and out of engine bay. Mine did similar but it needed the control flaps reset. It had climatronic system. With ignition on but not running press ECON and I think bottom left airflow button. The control flaps then reset by themselves. On mine there was a weird clicking noise from behind dash before heater stopped working.

Alasdair

Robert

On 11/03/2025 at 09:08, Alasdair1 said:

You should be able to flush matrix from the pipes into and out of engine bay. Mine did similar but it needed the control flaps reset. It had climatronic system. With ignition on but not running press ECON and I think bottom left airflow button. The control flaps then reset by themselves. On mine there was a weird clicking noise from behind dash before heater stopped working.

Alasdair

Thanks for that will give it a go

4 hours ago, pastiche said:

The control flaps then reset by themselves. On mine there was a weird clicking noise from behind dash before heater stopped working.

My experience is that the clicking noise is the worn teeth on the nylon gear are stripped or starting to strip. Even if a reset does get it working again for now, in the long term you will end up replacing the flap servo assembly.