I have a 2015 (64reg) black edition Octavia. Recently the heating system failed and would only blow cold air no matter the temp setting. The water pump and pulleys were changed last week along with the coolant system being flushed and renewed but didn’t sort the problem. Been in to the dealership this morning who have stated that the silicone bag in the expansion tank has failed and contaminated the coolant system and blocking the heater matrix. Quoted over £1300 to resolve as the expansion and matrix need changing but main cost is labour as the system will need to be flushed multiple times with a cleaner to get rid of any residue. Skoda have offered 25% goodwill but still over £1000 to pay. I feel the part is substandard and Skoda should contribute all or more to resolve. I’ve seen on here this has happened to others but does anyone know when it first appeared and if anyone else has had better luck with Skoda footing the bill? Thanks

It has certainly come up before.

 

The odd question is why was the water pump replaced if the heater wasn't getting hot, was this covered by warranty? If the engine was over heating I could understand it, or even if it was over cooling and taking a long time to warm up. But surely if the heater wasn't getting hot then the logical diagnosis would be: engine is warm, one heater matrix pipe is hot, the other is cooler, therefor the matrix is blocked.

The water pump/ cam belt needed doing anyway as it was slipping. Unfortunately nothing under warranty as that ended in march

The cam belt was slipping?

I would contact Skoda customer services direct and push for a higher goodwill contribution, it looks like this is going to be an issue repeated on here, another design issue, fine for most - but expensive if you happen to be unlucky and have your bag split.

3 minutes ago, Gti Jazz Blue said:

unlucky and have your bag split.

 

 

Well, my first thought, on reading the OP, was that the mixer flaps were stuck on "full cold" (or thereabouts). Of course, this would mean that the engine is getting hot (but not overheating), and that the heater supply pipe was also getting hot.

2 minutes ago, KenONeill said:

Well, my first thought, on reading the OP, was that the mixer flaps were stuck on "full cold" (or thereabouts). Of course, this would mean that the engine is getting hot (but not overheating), and that the heater supply pipe was also getting hot.

 

That would be my first line of thought to on reading that job card.

 

I'd get the engine up to temp, check the heater matrix pipes. If they were both hot, check diagnostics for flap operating. If one was hot and the other cooler, disconnect the heater matrix pipes and flow check the matrix.

Of course, that's two of us thought the same way, and didn't go near the water pump. Ok, the pump may have needed changing anyway, but the "expensive failure" is not proven.

Just to throw in a bit of a curve ball, but I had intermittent heater problems last year - 2015 vRS, blowing cold air when the car was up to temperature.  Lots of bits were replaced - heater control unit, temperature control unit, and the silica bag got a mention too.  It turned out to be the coolant check valve, registering it was open when it was actually closed.  I was given the green light by the Skoda dealership to pick the car up, while they ordered a replacement.  The turbo failed 20 minutes after collecting the car - I later found out that the check valve has a role in supplying coolant to the turbo.

 

Gaz 

8 hours ago, LankyC said:

I have a 2015 (64reg) black edition Octavia. Recently the heating system failed and would only blow cold air no matter the temp setting. The water pump and pulleys were changed last week along with the coolant system being flushed and renewed but didn’t sort the problem. Been in to the dealership this morning who have stated that the silicone bag in the expansion tank has failed and contaminated the coolant system and blocking the heater matrix. Quoted over £1300 to resolve as the expansion and matrix need changing but main cost is labour as the system will need to be flushed multiple times with a cleaner to get rid of any residue. Skoda have offered 25% goodwill but still over £1000 to pay. I feel the part is substandard and Skoda should contribute all or more to resolve. I’ve seen on here this has happened to others but does anyone know when it first appeared and if anyone else has had better luck with Skoda footing the bill? Thanks

The silica bag is mentioned in this thread.

 

Edited 31 July, 20196 yr by ords
Correction

An update a bit further down the line...the expansion tank and heater matrix were replaced in August along with a supposed clean of the system over a 10 hour period. After many emails the dealership/ Skoda UK agreed 50% so cost me just shy of £700. Five weeks later again there was cold air coming out of the vents when engine was up to temp. Taken back in and they have redone all the work again because apparently the silicone from the new expansion tank had leaked again! Thankful that this time it’s covered under their warranty for work they completed!