MK3 HEATER MATRIX REPLAEMENT

[skodavia]

I have just bought a 2014 mk3 1.6 tdi. I had the same problem with poor heater and discoloured coolant in the expansion tank. i tried the heater flap reset but this did not cure the problem. After trawling this forum it looked like the heater matrix was the fault. i checked the coolant pipes at the bulkhead as they go through into the heater matrix and they were just better than luke warm.

I did a ring round of the usual suppliers and the best i could get a matrix for was £90 inc vat. I'm in the trade so this was with trade discount. buycarparts.co.uk kept popping up on my browser so i thought i would take a look. The company is based in Germany but their prices are much much cheaper than anyone else. So i typed my reg number in and was given something like 15 options of manufacturer of a heater matrix that would fit my car. I opted for the cheapest one £20.99 inc vat plus delivery of £8.50 3-5 working days. it was manufactured by VAN WEZEL based in Belgium (checked their website).

 

Part came 4 days later unboxed it and all looked ok. drained the coolant from the car and removed and binned the mit silikat expansion bottle. a Quick shake of the bottle revealed the bag was still in there but it was the one placed between the walls of the bottle so no chance of getting it out. A new bottle was sourced from GSF as they had a deal on but in hindsight i should have ordered it from Germany and just paid one lot of postage. Coolant system was flushed out with the hose pipe until it ran clear and left to drain.

 

Moving inside the car i removed the glovebox which was very tricky but i later watched a youtube video and it could have been a lot easier but i got it out with no damage and all of my skin still on my fingers. The side trim for the centre console was removed, one t20 screw and the panel just unclipped. there was a foam trim under the heater motor that was held in with two plastic wing nut type screws this came off to reveal the heater motor that needs to come out to enable the matrix to be removed. The motor is held in with 3 t20 screws and there are two clips that need easing away to enable the heater to drop down but before this you need to unplug the power connector underneath. Sorry forgot to say before the heater motor comes out there is a heater vent that directs air to the passenger feet, this needs to come out and there is one t20 screw that holds it in, the screw faces you just by the fusebox, once this is out you have to contort the vent out after pulling it free of the heater box. It was a bit fiddly but it came out ok.

 

With all these parts out if you look towards the centre console side of the dash you will see the heater matrix pipes. covering the heater matrix is an oblong black cover held on with 3 t20 screws. the screws need removing and there are 3clips that also secure the panel. I covered the floor area with a plastic sheet to contain any leaks from when the matrix pipes were removed.

The pipes are secured by a clip and a clamp. the top pipe has a clip that has a locking tab that needs to be lifted before the clip can be slid backwards to remove. The bottom pipe has a clamp that is held together with a 3mm allen bolt. Before removing the pipes there is a plastic piece that bolts to the transmission tunnel (it's what the t20 screw that holds the centre console trim screws into) peel the carpet back and there are 2 10mm nuts that need to be removed. Once this is out of the way it gives more movement of the heater pipes as they need to be moved to enable the matrix to slide out.

 

A quick tug on the pipes frees them from the matrix along with 200ml of coolant ( i had an old ice cream tub on hand to catch as much as i could). Once the pipes are removed you can then unclip the oblong cover that covers the end of the matrix. It has a green seal all the way around presumably to help seal the air into the heater box. As stated earlier the pipes need to be jiggled around and the matrix should slide out towards the heater motor housing, it will hit the housing but then a slight movement downwards will let it come past and the matrix is out.

 

I looked inside and could not see any blockages but when i filled it with water it did not flow very well. Fitting the new matrix is basically a reversal of the procedure above. things to be careful about are: when sliding the new matrix back in be sure to get your head right up behind the matrix to make sure the top pipe is not fouling the fins on the back of the matrix as this will hinder it going back in. The new matrix i got seemed a little tighter to fit than the old one that came out but i took my time and made sure it went in evenly to make sure it was fully home. remember then the oblong cover needs to go on before any pipes are fitted. I cleaned the pipes and re used the old o ring seals and just put a tiny smear of rubber grease on the o rings which helped them slide back into the new matrix part number of the seal and clamp kit is 5Q0-898-400-A same part number whether sourced from VW SEAT or SKODA but VW are the cheapest at £5.51 whereas Seat and SKODA wanted £9.91!! getting the top clip on for the pipe was easy but the bottom one gave me a bit of pain. I think because it was slightly out of round where i had removed it but i took it back off and fitted it to the old matrix to make sure it was shaped properly.

 

After all this i refilled the coolant and what i am about to type may not be to everyone's liking but i filled the coolant with G12 as it's what we use on the commercial vehicles we repair that have aluminium radiators. Also we run a fleet of VW caddy vans and i checked our 67 plate caddy that has the same engine as my octavia and the coolant tank on the caddy states G12??

 

Unfortunately i did not get any pictures but there are videos on youtube of this repair being done. Book time is 1.4hours, probably doable if you worked at skoda but i would allow 3 hours to comfortably do it. like most things if you take your time and watch youtube so you have an idea of what is involved then doing the matrix on one of these is not a scary prospect. Tools wise i used

T20 screwdriver

10mm socket and ratchet

1/4 drive ratchet with T20 bit for rearmost heater motor screw

Flat blade screwdriver

3mm allen key

Torch and that's it!

Heater now works a treat with heat evenly at both sides.

 

Hope this helps

[Jim Reire]

On 27/10/2020 at 09:56, skodavia said:

I have just bought a 2014 mk3 1.6 tdi. I had the same problem with poor heater and discoloured coolant in the expansion tank. i tried the heater flap reset but this did not cure the problem. After trawling this forum it looked like the heater matrix was the fault. i checked the coolant pipes at the bulkhead as they go through into the heater matrix and they were just better than luke warm.

I did a ring round of the usual suppliers and the best i could get a matrix for was £90 inc vat. I'm in the trade so this was with trade discount. buycarparts.co.uk kept popping up on my browser so i thought i would take a look. The company is based in Germany but their prices are much much cheaper than anyone else. So i typed my reg number in and was given something like 15 options of manufacturer of a heater matrix that would fit my car. I opted for the cheapest one £20.99 inc vat plus delivery of £8.50 3-5 working days. it was manufactured by VAN WEZEL based in Belgium (checked their website).

 

Part came 4 days later unboxed it and all looked ok. drained the coolant from the car and removed and binned the mit silikat expansion bottle. a Quick shake of the bottle revealed the bag was still in there but it was the one placed between the walls of the bottle so no chance of getting it out. A new bottle was sourced from GSF as they had a deal on but in hindsight i should have ordered it from Germany and just paid one lot of postage. Coolant system was flushed out with the hose pipe until it ran clear and left to drain.

 

Moving inside the car i removed the glovebox which was very tricky but i later watched a youtube video and it could have been a lot easier but i got it out with no damage and all of my skin still on my fingers. The side trim for the centre console was removed, one t20 screw and the panel just unclipped. there was a foam trim under the heater motor that was held in with two plastic wing nut type screws this came off to reveal the heater motor that needs to come out to enable the matrix to be removed. The motor is held in with 3 t20 screws and there are two clips that need easing away to enable the heater to drop down but before this you need to unplug the power connector underneath. Sorry forgot to say before the heater motor comes out there is a heater vent that directs air to the passenger feet, this needs to come out and there is one t20 screw that holds it in, the screw faces you just by the fusebox, once this is out you have to contort the vent out after pulling it free of the heater box. It was a bit fiddly but it came out ok.

 

With all these parts out if you look towards the centre console side of the dash you will see the heater matrix pipes. covering the heater matrix is an oblong black cover held on with 3 t20 screws. the screws need removing and there are 3clips that also secure the panel. I covered the floor area with a plastic sheet to contain any leaks from when the matrix pipes were removed.

The pipes are secured by a clip and a clamp. the top pipe has a clip that has a locking tab that needs to be lifted before the clip can be slid backwards to remove. The bottom pipe has a clamp that is held together with a 3mm allen bolt. Before removing the pipes there is a plastic piece that bolts to the transmission tunnel (it's what the t20 screw that holds the centre console trim screws into) peel the carpet back and there are 2 10mm nuts that need to be removed. Once this is out of the way it gives more movement of the heater pipes as they need to be moved to enable the matrix to slide out.

 

A quick tug on the pipes frees them from the matrix along with 200ml of coolant ( i had an old ice cream tub on hand to catch as much as i could). Once the pipes are removed you can then unclip the oblong cover that covers the end of the matrix. It has a green seal all the way around presumably to help seal the air into the heater box. As stated earlier the pipes need to be jiggled around and the matrix should slide out towards the heater motor housing, it will hit the housing but then a slight movement downwards will let it come past and the matrix is out.

 

I looked inside and could not see any blockages but when i filled it with water it did not flow very well. Fitting the new matrix is basically a reversal of the procedure above. things to be careful about are: when sliding the new matrix back in be sure to get your head right up behind the matrix to make sure the top pipe is not fouling the fins on the back of the matrix as this will hinder it going back in. The new matrix i got seemed a little tighter to fit than the old one that came out but i took my time and made sure it went in evenly to make sure it was fully home. remember then the oblong cover needs to go on before any pipes are fitted. I cleaned the pipes and re used the old o ring seals and just put a tiny smear of rubber grease on the o rings which helped them slide back into the new matrix part number of the seal and clamp kit is 5Q0-898-400-A same part number whether sourced from VW SEAT or SKODA but VW are the cheapest at £5.51 whereas Seat and SKODA wanted £9.91!! getting the top clip on for the pipe was easy but the bottom one gave me a bit of pain. I think because it was slightly out of round where i had removed it but i took it back off and fitted it to the old matrix to make sure it was shaped properly.

 

After all this i refilled the coolant and what i am about to type may not be to everyone's liking but i filled the coolant with G12 as it's what we use on the commercial vehicles we repair that have aluminium radiators. Also we run a fleet of VW caddy vans and i checked our 67 plate caddy that has the same engine as my octavia and the coolant tank on the caddy states G12??

 

Unfortunately i did not get any pictures but there are videos on youtube of this repair being done. Book time is 1.4hours, probably doable if you worked at skoda but i would allow 3 hours to comfortably do it. like most things if you take your time and watch youtube so you have an idea of what is involved then doing the matrix on one of these is not a scary prospect. Tools wise i used

T20 screwdriver

10mm socket and ratchet

1/4 drive ratchet with T20 bit for rearmost heater motor screw

Flat blade screwdriver

3mm allen key

Torch and that's it!

Heater now works a treat with heat evenly at both sides.

 

Hope this helps

 Very helpful post indeed skodavia. Thanks for posting. I need some advice about how bleeding the system went after installing the Matrix., if you wouldn't mind?  In my Superb ( 2015 1.6 3V , but presumably the same set up?) I have just replaced the "Mit Silikat" tank as I was unable ( like you)  to extract the "Teabag" from between the twin walls. I replaced the antifreeze lost during the job with G13 concentrate, but as the car is now 5 years old ( but just 80'000 Klms ) I plan on carrying out a drain and flush. From what I'm hearing, in these engines its not so simple..apparently  there are 3 different pumps ( depending on the model) and these need to be activated electronically during the draining process?  Did you have to do this when draining/ refilling your car? Thanks for your help

[skodavia]

I didnt activate any pumps when draining. I'm sure there is a specific way of doing this. Maybe someone can elaborate on this. I drained the cooling system by removing both hoses from the rad and removing the expansion tank (this was to be changed anyway) i also removed the hoses at the bulkhead for the matrix and then flushed it through with a hose pipe, both ways until it ran clear. I then let all the water drain out and then rebuilt it. As i stated in my post i put G12 coolant in (I plan to change the coolant again in the spring)

[Jim Reire]

12 hours ago, skodavia said:

I didnt activate any pumps when draining. I'm sure there is a specific way of doing this. Maybe someone can elaborate on this. I drained the cooling system by removing both hoses from the rad and removing the expansion tank (this was to be changed anyway) i also removed the hoses at the bulkhead for the matrix and then flushed it through with a hose pipe, both ways until it ran clear. I then let all the water drain out and then rebuilt it. As i stated in my post i put G12 coolant in (I plan to change the coolant again in the spring)

 And no issues re bleeding all the air out of the system afterwards?? ... Just fill it up with coolant turn on the heating and run the engine, topping it up as needed, and it has been fine since? Thats good news...I had heard that it was a complicated process, and  it needed to  be plugged into  VAG-COM  to operate the pumps and thermostat. 

Thanks for your helpful post.

[Rhids]

(newbie 2016 1.6 tdi 110bhp otavia scout, 50,000miles.  Dealer serviced from new).

 

OK, so around one-two months ago low coolant light came on. Didn't think too much of it, topped it up (quite more than I anticipated approx 800mls). At no point has car overheated, temp gone up.

 

Wife borrowed car recently and complained that heater not working. Again didn't think much of it.😜

 

Oil service this week and wife agreed to sales rep selling air con recharge(!).

 

I drive the car today and turns out she is right! Passenger side not too bad (but not great), driver side cold.

 

After a lot of reading suspect silica bag broken and matrix blocked.

 

Questions:

 

1. Where has the lost coolant gone?

2. Replace matrix and coolant only

3. Replace matrix, coolant, expansion fill bottle.

4. Replace anything else?

5. Dealer or DIY (fairly competentent)

6. Dealer recharged air con on faulty heating system!

 

Thanks for advice.

[Jim Reire]

1 hour ago, Rhids said:

(newbie 2016 1.6 tdi 110bhp otavia scout, 50,000miles.  Dealer serviced from new).

 

OK, so around one-two months ago low coolant light came on. Didn't think too much of it, topped it up (quite more than I anticipated approx 800mls). At no point has car overheated, temp gone up.

 

Wife borrowed car recently and complained that heater not working. Again didn't think much of it.😜

 

Oil service this week and wife agreed to sales rep selling air con recharge(!).

 

I drive the car today and turns out she is right! Passenger side not too bad (but not great), driver side cold.

 

After a lot of reading suspect silica bag broken and matrix blocked.

 

Questions:

 

1. Where has the lost coolant gone?

2. Replace matrix and coolant only

3. Replace matrix, coolant, expansion fill bottle.

4. Replace anything else?

5. Dealer or DIY (fairly competentent)

6. Dealer recharged air con on faulty heating system!

 

Thanks for advice.

 For the "Missing" coolant , I'd be looking at the waterpump.  Check for water / coolant staining  around the pump itself. It's recommended that they be replaced between 60-90'000 Miles, but they can go sooner. i would not be too impressed with any water pump that lasted less than 100'000 MIle's in any car.

Edited 13 November, 2020 by Jim Reire

[Rhids]

Would the water pump be replaced by a newer more robust trouble free version?🤞

[Jim Reire]

On 14/11/2020 at 14:33, Rhids said:

Would the water pump be replaced by a newer more robust trouble free version?🤞

Having just replaced the timing belt and waterpump on my 152 Superb at 80'000Klms  / 49700 Miles. I can't really say just yet if it's the "new Improved" version...maybe someone here on the forum cam help? But  I do know that in many other makes and models, its standard practice to replace a part with a high failure / premature failure rate with an improved version.  When a brand new model comes on the market, and even with exhaustive testing prior to release,  its the general buying public who shoulder the brunt of real-life driving conditions, and thats when design faults become apparent. Generally, when the 3 yearly upgraded version comes along, a lot of the kinks which were in the original  have been ironed out.  And the VAG 1.6 engine is long enough in production now to have all the kinks sorted, especially short life water pumps....Its a black mark against  an otherwise very good engine.

 

Edited 16 November, 2020 by Jim Reire

[skodavia]

re your list:

 

change the matrix, coolant and expansion tank for one that does not contain a silica bag

if coolant pump is leaking then obviously change tis as well

if you're here then you will have read my post on how to do this. I would say this is easily do able by a competent diy mechanic, just take your time have a read of what i did and also have a look on youtube, this is what i did before i attempted mine and there is a decent video on there of someone doing a mk3 octavia.

A bit naughty of the dealer to recommend a/c regas but not fully check the heating to tell you that the heater does not work. why did they want to do the a/c?

[Jim Reire]

Re changing and flushing out the existing coolant in the VAG engines, I've just seen a video pf a very simple way to do this, and its something that I'm going to try myself.  Run engine until it's hot. Then remove the header tank return pipe from the tank, and connect it to a long piece of plastic tubing ( 4-5 ft or 1 metre ) place the other end into a suitable container. (20-25 Litres) Start engine, and as the  old fluid is being pumped out, replace it with either new coolant, or ordinary water if you want to do a full flush.  While this is going on, have the heater controls switched to maximum heat and fan settings. 

[skodavia]

good idea, let us know how you get on

[Rhids]

She's at the stealers. New matrix and to be flushed 7 times. That's gonna cost me.

 

Dealer said coolant looks contaminated and tank doesn't have silica bag in it, despite stating mit silica on outside.

 

Could he mean tank is double skinned with silica in between?

 

 

[Rhids]

She's back!

 

"Debris in coolant", unable to explain or clarify further. Denied presence of silica bag in tank.

New matrix, flushed, new expansion tank -£1345.

 

Got a free bottle of coolant though!

When I enquired as to why its a bottle of G12evo (vw) and not G13 nice lady told me its all the same.

 

New expansion tank no longer has mit silica on it nor specifies coolant type!

 

Cant wait for the £600 Cam belt change in 3 months.

 

[xman]

G12evo is the latest incarnation of VW coolant and replaces all previous versions including G13, G12, G12+,G12++ and G11. Nobody knows why they didnt call it G13+ or similar.

 

No silca bag found is imo a red herring, the bag probably disintegrated and the silikat stuff got released and blocked the heater matrix and maybe parts of the radiator.

 

Although VW would never admit it, I've read somewhere online that the problem of silica bag failure is possibly due to silica bag material incompatabilty with G13 coolant maybe partly behind the change of coolant spec and removal of dubious silica bags on later cars.

 

Edited 30 November, 2020 by xman

[Jim Reire]

On 29/11/2020 at 23:08, Rhids said:

She's at the stealers. New matrix and to be flushed 7 times. That's gonna cost me.

 

Dealer said coolant looks contaminated and tank doesn't have silica bag in it, despite stating mit silica on outside.

 

Could he mean tank is double skinned with silica in between?

 

 

 I have attached a pic of the  header tank that I have replaced in my 152 Superb. As you can see, its doubled walled where the silicate bag resides..its the faint pink color, and no way to access it, unlike older models where it was possible to extract it from it's cage.  Hard to figure out where your silikat  vanished though.. Had to be in to the coolant, Where else could it have gone? And of course if it escaped and mixed with the coolane, it might not show any visible signs in the color of the coolant. But I'm pretty sure that the veins in the matrix will show plenty of evidence of what has blocked it. I don't follow this "debris" explanation one bit......If it was some kind of "Debris", then I'm pretty sure that it would have been flagged a long time ago, with other Skoda owners, and some explanation given. But if it WAS a debris, then the only 2 ways it could have entered the system, A, you topped it up with something that was contaminated, or B the Antifreeze / coolant itself reacted with the metals in the engine and created an oxide. Question is, which is it? Personally, I'd be going for "B" with the silikat being the culprit.

[Jim Reire]

6 hours ago, Rhids said:

She's back!

 

"Debris in coolant", unable to explain or clarify further. Denied presence of silica bag in tank.

New matrix, flushed, new expansion tank -£1345.

 

Got a free bottle of coolant though!

When I enquired as to why its a bottle of G12evo (vw) and not G13 nice lady told me its all the same.

 

New expansion tank no longer has mit silica on it nor specifies coolant type!

 

Cant wait for the £600 Cam belt change in 3 months.

 

Normally, when changing the belt, the following kit is used :-   tensioners, idlers, dampers, gaskets and even a water pump where required, as well as the belt itself. The reason for replacing the waterpump is that the timing belts have have much longer service life than the water pumps, so it has evolved that when you change one, you change all.. I've had mine done recently @ 80'000 Klms.  The pump was starting to leak minute qtys of coolant, and as the car had reached its 5th Birthday in September, I changed everything, even though theoretically( and according to the service schedule) the belt was good for at least another 50-60'000 Klms. It also makes sense because when fitting the pump, the pulleys and belts etc have to be removed t as well

[Rhids]

Well after driving home (10 miles) and instructed to check coolant level this am its pretty damn cloudy.

 

Not really what I expected for £1345!

 

Should this be so?

[xman]

I would say it's still heavily contaminated, it should be clear to see through and bright pink. They haven't flushed it sufficiently (if at all) or (hopefully not) mixed incompatible fluids/not used distilled water/not actually done as stated on invoice.

 

Definitely not what £1345 should look like.

 

Alternatively, your head gasket is gone and exhaust gases and/or oil is contaminating the coolant (you will also invariably lose coolant in this scenario). There appears to be evidence of some oil or other substance floating in the top photo.

 

A competent dealer would have checked this first with a chemical test.

 

Hopefully not this fault as that will be expensive to fix.

 

Keep a coolant sample as evidence, take another sample back to them and complain. Contact them first to save a wasted journey and record the conversation (most mobiles can do that). If you feel fobbed off, phone and register a complaint with Skoda UK.

 

This is the colour it should be

 

 

Edited 1 December, 2020 by xman

[Jim Reire]

Rhids , I'll check the color of my superb in the morning, but I'm more than 100% sure that its absolutely  nothing like that...pink as pink could be if my memory serves me right after the water pump was done and the coolant replaced as part off the job.  If  this  is the same color that it was pre fitting of the matrix etc. it would explain what the garage meant when they said that it was contaminated,,,but could not say with what..I'd be looking at the head gasket at this stage. That color is not normal. Take it back and at least discuss it with them,  Then if in doubt, get an independent opinion.

 

[doll321]

Can anybody provide a part number fot a 2014 octavia heater matrix please, thanks.

[Breezy_Pete]

@doll321 there appear to be two distinct part numbers depending on whether your car has a Valeo or Denso HVAC system fitted.

5Q0 819 031 in the first case, 5Q0 819 031A in the second.

I doubt these are interchangeable otherwise there would just be one part number. Message me with your VIN if you'd like me to try to check which your vehicle needs.

All the relevant ETKA pages have the caveat "Before parts order, physical inspection of old part necessary" in their titles, which might be challenging in the case of a heater matrix, not sure how hard access is.

[ApertureS]

On 08/09/2023 at 10:48, Breezy_Pete said:

@doll321 there appear to be two distinct part numbers depending on whether your car has a Valeo or Denso HVAC system fitted.

5Q0 819 031 in the first case, 5Q0 819 031A in the second.

I doubt these are interchangeable otherwise there would just be one part number. Message me with your VIN if you'd like me to try to check which your vehicle needs.

All the relevant ETKA pages have the caveat "Before parts order, physical inspection of old part necessary" in their titles, which might be challenging in the case of a heater matrix, not sure how hard access is.

Sadly you can’t tell with the VIN, it involves a physical check.

 

The easiest way to tell is look under the dashboard under the glovebox at the bottom of the blower motor, or open the glovebox and look behind at the pollen filter flap.

 

Either of these will be stamped Valeo or Denso and no the matrix can’t be swapped for one or the other and the fitting kit with clamps and seals is also specific to the brand of matrix 

[Breezy_Pete]

Yeah, I found that out after they sent me the VIN. I suggested the same strategy of looking at blower motor for any telltale brand label.

I didn't know the specifics of access though, so thanks for adding. 

Edited 13 October, 2023 by Breezy_Pete

[Chathura]

On 27/10/2020 at 09:56, skodavia said:

I have just bought a 2014 mk3 1.6 tdi. I had the same problem with poor heater and discoloured coolant in the expansion tank. i tried the heater flap reset but this did not cure the problem. After trawling this forum it looked like the heater matrix was the fault. i checked the coolant pipes at the bulkhead as they go through into the heater matrix and they were just better than luke warm.

I did a ring round of the usual suppliers and the best i could get a matrix for was £90 inc vat. I'm in the trade so this was with trade discount. buycarparts.co.uk kept popping up on my browser so i thought i would take a look. The company is based in Germany but their prices are much much cheaper than anyone else. So i typed my reg number in and was given something like 15 options of manufacturer of a heater matrix that would fit my car. I opted for the cheapest one £20.99 inc vat plus delivery of £8.50 3-5 working days. it was manufactured by VAN WEZEL based in Belgium (checked their website).

 

Part came 4 days later unboxed it and all looked ok. drained the coolant from the car and removed and binned the mit silikat expansion bottle. a Quick shake of the bottle revealed the bag was still in there but it was the one placed between the walls of the bottle so no chance of getting it out. A new bottle was sourced from GSF as they had a deal on but in hindsight i should have ordered it from Germany and just paid one lot of postage. Coolant system was flushed out with the hose pipe until it ran clear and left to drain.

 

Moving inside the car i removed the glovebox which was very tricky but i later watched a youtube video and it could have been a lot easier but i got it out with no damage and all of my skin still on my fingers. The side trim for the centre console was removed, one t20 screw and the panel just unclipped. there was a foam trim under the heater motor that was held in with two plastic wing nut type screws this came off to reveal the heater motor that needs to come out to enable the matrix to be removed. The motor is held in with 3 t20 screws and there are two clips that need easing away to enable the heater to drop down but before this you need to unplug the power connector underneath. Sorry forgot to say before the heater motor comes out there is a heater vent that directs air to the passenger feet, this needs to come out and there is one t20 screw that holds it in, the screw faces you just by the fusebox, once this is out you have to contort the vent out after pulling it free of the heater box. It was a bit fiddly but it came out ok.

 

With all these parts out if you look towards the centre console side of the dash you will see the heater matrix pipes. covering the heater matrix is an oblong black cover held on with 3 t20 screws. the screws need removing and there are 3clips that also secure the panel. I covered the floor area with a plastic sheet to contain any leaks from when the matrix pipes were removed.

The pipes are secured by a clip and a clamp. the top pipe has a clip that has a locking tab that needs to be lifted before the clip can be slid backwards to remove. The bottom pipe has a clamp that is held together with a 3mm allen bolt. Before removing the pipes there is a plastic piece that bolts to the transmission tunnel (it's what the t20 screw that holds the centre console trim screws into) peel the carpet back and there are 2 10mm nuts that need to be removed. Once this is out of the way it gives more movement of the heater pipes as they need to be moved to enable the matrix to slide out.

 

A quick tug on the pipes frees them from the matrix along with 200ml of coolant ( i had an old ice cream tub on hand to catch as much as i could). Once the pipes are removed you can then unclip the oblong cover that covers the end of the matrix. It has a green seal all the way around presumably to help seal the air into the heater box. As stated earlier the pipes need to be jiggled around and the matrix should slide out towards the heater motor housing, it will hit the housing but then a slight movement downwards will let it come past and the matrix is out.

 

I looked inside and could not see any blockages but when i filled it with water it did not flow very well. Fitting the new matrix is basically a reversal of the procedure above. things to be careful about are: when sliding the new matrix back in be sure to get your head right up behind the matrix to make sure the top pipe is not fouling the fins on the back of the matrix as this will hinder it going back in. The new matrix i got seemed a little tighter to fit than the old one that came out but i took my time and made sure it went in evenly to make sure it was fully home. remember then the oblong cover needs to go on before any pipes are fitted. I cleaned the pipes and re used the old o ring seals and just put a tiny smear of rubber grease on the o rings which helped them slide back into the new matrix part number of the seal and clamp kit is 5Q0-898-400-A same part number whether sourced from VW SEAT or SKODA but VW are the cheapest at £5.51 whereas Seat and SKODA wanted £9.91!! getting the top clip on for the pipe was easy but the bottom one gave me a bit of pain. I think because it was slightly out of round where i had removed it but i took it back off and fitted it to the old matrix to make sure it was shaped properly.

 

After all this i refilled the coolant and what i am about to type may not be to everyone's liking but i filled the coolant with G12 as it's what we use on the commercial vehicles we repair that have aluminium radiators. Also we run a fleet of VW caddy vans and i checked our 67 plate caddy that has the same engine as my octavia and the coolant tank on the caddy states G12??

 

Unfortunately i did not get any pictures but there are videos on youtube of this repair being done. Book time is 1.4hours, probably doable if you worked at skoda but i would allow 3 hours to comfortably do it. like most things if you take your time and watch youtube so you have an idea of what is involved then doing the matrix on one of these is not a scary prospect. Tools wise i used

T20 screwdriver

10mm socket and ratchet

1/4 drive ratchet with T20 bit for rearmost heater motor screw

Flat blade screwdriver

3mm allen key

Torch and that's it!

Heater now works a treat with heat evenly at both sides.

 

Hope this helps

 

Your post is truly helpful! Especially, listing down the required tools will give a better chance to anyone to prepare for this in advance.

 

Re: Coolant draining:

However, in my case, I may have to bring the car to a garage as I don't have the jacks or ramps to lift the car to remove the cover under the engine. Maybe, it would be a good idea to update your original post including those also as tools if there are no alternatives.

 

Re: Product buyer recommendation/advice:

I have an Octavia MK3 (2016) and I looked for OEM products when looking for a new heater matrix and an expansion bottle. However, I couldn't even find anything branded as Skoda or VW. Instead, I found a set of different products including Valeo. Therefore, I came to the briskoda forum looking for some advice.