Hi all just thought I would share the issue I’ve had with heater blower temp. Paseger side was hot … driver side blowing cold , turns out it was the heater matrix core. bought one online direct from Lithuania for £40 brand new … identical to original part. anyways followed the instructions on you tube, fairly straightforward if a tad fiddly. Nothing the diy man can’t complete. anyhow …. Just wanted to show you the culprit … a gelatinous goo that was blocking the matrix. It felt like slime.