These are the notes I've taken off various forums to replace the matrix. The You Tube video was helpful, albeit on an Octavia. They are all slightly different.
I have got some photos as well if that helps.
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Replace Heater Matrix
The part number for the heater core is 5Q0819031B - Denso or Valeo??
5Q0 819 422 A for Valeo and 5Q0 819 422 for Denso
Or Nissan 73980
Heater unit diagram
https://nemigaparts.com/cat_spares/etka/seat/le/754/819200/
I’ll be changing the matrix with fitting kit, new expansion tank, new g13 coolant with distilled water 50/50 ratio.
All done, took about 3 hours including finding tools and a test drive as it wasn't heating up with no load on it. All back together and no leaks at full temperature.
Got the heater matrix out without removing the glove box, just need to remove the air distributor and the blower motor to get enough clearance.
Got loads of scale out as soon as the lower pipe came off. Ordered a new heater matrix yesterday morning and it arrived by lunchtime knowing that I could return it if that wasn't the issue.
You don't even need to remove the blower motor. Just one bolt holding on the air distributor which you can get out of the way fairly easily.
Reckon you'll have the new one fitted in under an hour.
As mentioned, I had a go at driving the car at high revs for a while to raise the water pump pressure around the system.
Upper bulkhead hose is hot and the lower one only warm-ish so looks like blocked heater matrix.
https://forums.seatcupra.net/index.php?threads/aircon-and-heater-doesnt-work.432793/page-4
Extra images: http://forums.tdiclub.com/showthread.php?t=483783&page=11
When refitting, I realised that I really didn't need to pull all that crap out to get to it. You can literally get it out by:
Draining coolant
Removing:
2x heater matrix hoses in the bulkhead
1x Torx screw on 'skirt' under the centre console
1x Torx screw on the lower pipe clip
1x Torx screw behind the glovebox (just flip it down as you would for a pollen filter change) to remove the air duct for more access room
2x Torx screws for the flap holding the matrix in place
Octavia video:
And that is literally it! On reflection, I honestly believe the draining, removing/refitting of the matrix and filling back up with fluid could be done in under 2 hours. And that is by me - a ham-fisted DIY'er. How these garages have taken days and even weeks to do this job, is beyond me!
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I have got some photos as well if that helps.
-----------------------
Replace Heater Matrix
The part number for the heater core is 5Q0819031B - Denso or Valeo??
5Q0 819 422 A for Valeo and 5Q0 819 422 for Denso
Or Nissan 73980
Heater unit diagram
https://nemigaparts.com/cat_spares/etka/seat/le/754/819200/
I’ll be changing the matrix with fitting kit, new expansion tank, new g13 coolant with distilled water 50/50 ratio.
All done, took about 3 hours including finding tools and a test drive as it wasn't heating up with no load on it. All back together and no leaks at full temperature.
Got the heater matrix out without removing the glove box, just need to remove the air distributor and the blower motor to get enough clearance.
Got loads of scale out as soon as the lower pipe came off. Ordered a new heater matrix yesterday morning and it arrived by lunchtime knowing that I could return it if that wasn't the issue.
You don't even need to remove the blower motor. Just one bolt holding on the air distributor which you can get out of the way fairly easily.
Reckon you'll have the new one fitted in under an hour.
As mentioned, I had a go at driving the car at high revs for a while to raise the water pump pressure around the system.
Upper bulkhead hose is hot and the lower one only warm-ish so looks like blocked heater matrix.
https://forums.seatcupra.net/index.php?threads/aircon-and-heater-doesnt-work.432793/page-4
Extra images: http://forums.tdiclub.com/showthread.php?t=483783&page=11
When refitting, I realised that I really didn't need to pull all that crap out to get to it. You can literally get it out by:
Draining coolant
Removing:
2x heater matrix hoses in the bulkhead
1x Torx screw on 'skirt' under the centre console
1x Torx screw on the lower pipe clip
1x Torx screw behind the glovebox (just flip it down as you would for a pollen filter change) to remove the air duct for more access room
2x Torx screws for the flap holding the matrix in place
Octavia video:
And that is literally it! On reflection, I honestly believe the draining, removing/refitting of the matrix and filling back up with fluid could be done in under 2 hours. And that is by me - a ham-fisted DIY'er. How these garages have taken days and even weeks to do this job, is beyond me!
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