Climatronic heater

Climatronic heaters are available in different versions. By default, there are LHD and RHD versions. I will focus on the LHD version, because it’s more popular. Another reason is that my car is also LHD 😛
There is version with additional air hose to glovebox and without it. Cars with a diesel engine are heating up more slowly, so their heater has an supplementary heater AKA a uxiliary air heater (PTC). PTC takes more electricity, so it requires a good battery and an alternator with a larger capacity than the standard one (pay attention to this i f you intend to retrofit it in a gasoline engine).

Cars with PTC (6R0963235) from factory (just examples):

➔ VW POLO 6R, 6C 1.6 TDI, 1.4 TDI CUSB (2009-2017)
➔ SEAT I BIZA I V 6P 5D 1.4 TDI 2016SEAT TOLEDO I V TDI 2013
➔ Skoda FABIA I I FL 2014 1.6 TDI
➔ Skoda FABIA I I 2009 1.4 TDI BMS
➔ Audi A1 2011-15 8X0

Frequent differences in part numbers: click here.

Differences in the heater housing

Heaters unit can be divided according to the presence of:

  1. Glovebox – cooled glovebox (storage compartment)
    1. glovebox without cooling
    2. cooled glovebox
  2. Air heater
    1. standard heat exchanger
    2. auxiliary air heater (PTC) → mainly cars with TDI engine, PR-7E6

1.a. without cooled glove box

1.b. with cooled glove box

connection piece, LHD: 6Q1820723A (6Q1 820 723 A)
air hose for vehicles with air condit.: 6R0816311(6R0 816 311)
valve: 1J0816355(1J0 816 355)

2.a. without air heater (without PTC)

2.b. with auxiliary air heater (PTC)

some part numbers:

  • 6R1820003EC (6R1 820 003 EC) – without air hose to glovebox, Polo 2013, 2014
  • 6RU820003AL (6RU 820 003 AL) – without air hose to glovebox, Polo Sedan 2013
  • 6R1820003ED (6R1 820 003 ED) – with air hose to glovebox, Polo 2013, 2014
  • 6R1820003AD (6R1 820 003 AD) – with air hose to glovebox, Polo 1.4 CGGB 2009, Polo 1.2 TSI 2010
  • 6R1820003AE (6R1 820 003 AE) – with air hose to glovebox, Polo 1.6 TDI 2009, 2010
  • 6C1820003K (6C1 820 003 K) – with air hose to glovebox, Polo 2013, 2014
  • 6C1820003P (6C1 820 003 P) – with air hose to glovebox, Polo 1.2 TSI 2015
  • 6C1820003Q (6C1 820 003 Q) – with air hose to glovebox & PTC, Polo 1.4 TDI 2014, 2015
  • 6C1820003L (6C1 820 003 L) – with air hose to glovebox & PTC, Polo 1.4 TDI 2016
Photos of Climatronic heaters

1.a. & 2.a. Heater housing to Climatronic without air hose to glovebox, without PTC
eg. 6R1820003EC (6R1 820 003 EC)

This i s version of heater housing to cars without cooled glove box. There i s no air hose i n i t.

1.b. & 2.a. H eater housing to Climatronic with air hose to glovebox, without PTC
eg. 6C1820003K (6C1 820 003 K)

1.b & 2.b. Heater housing to Climatronic with air hose to glovebox, with electric auxiliary air heater (PTC)
eg. 6C1820003Q (6C1 820 003 Q)

thick GND wire i s for PTC i n cars with TDI engine if wire from heater has this red connector – i t’s heater from Climatronic
if wire from heater has this red connector – i t’s heater from Climatronic
What’s inside heater unit?
Differences in expansion valve

The expansion valve atomises incoming refrigerant and regulates the flow so that, depending on the heat transport, the vapour does not become a gas until i t reaches the outlet of the evaporator.

The expansion valve removes pressure from the l iquid refrigerant to allow expansion or change of state from a l iquid to a vapor i n the evaporator. The high-pressure l iquid refrigerant
entering the expansion valve is quite warm. This may be verified by feeling the liquid line at its connection to the expansion valve. The liquid refrigerant leaving the expansion valve is quite cold. The orifice within the valve does not remove heat, but only reduces pres sure. Heat molecules contained in the liquid refrigerant are thus allowed to spread as the refrigerant moves out of the orifice. Under a greatly reduced pressure the liquid refrigerant is at its coldest as it leaves the expansion valve and enters the evaporator.

Pressures at the inlet and outlet of the expansion valve will closely approximate gauge pressures at the inlet and outlet of the compressor in most systems. The similarity of pressures is caused by the closeness of the components to each other. The slight variation in pressure readings of a very few pounds is due to resistance, causing a pressure drop in the lines and coils of the evaporator and condenser.

Depending on the engine an model year of car, the air conditioning pipes AKA refrigerant lines (expansion valves > a/c condenser) are different, so so the difference is also in
expansion valve.

In case you need to change this part, try not to get it dirty. On the newer models of the Polo 6C, the expansion valve is usually different because the refrigerant lines are installed from the top, not from the bottom, so if you buy a newer heater (2014-2017 Europe hatchback) probably you will have to change this valve also (like me).

The expansion valve is screwed to evaporator with two socket head bolts
M5x40x16 (5 Nm) → N 10476301 (N 104 763 01).

NEO S2 3 – hex screwdriver bit H3

Old type

New type

screwed from the top ( VW Polo 6R 1.2 TSI CBZC 66kW 2013, LHD)
screwed from the bottom ( VW Polo 6C 1.2 TSI CJZ 2015, RHD)
aircon hoses in VW Polo 6RU 1.6 2016 (Russian sedan, still like European 6R)
aircon hoses in VW Polo 6C GTI 1.8 TSI 2015
aircon hoses in Polo 6R 2011 1.2 TDI Bluemotion, model year 2012
aircon hoses in VW Polo 6C GTI 1.8 TSI 2015
expansion valve in my 6R 1.4 CGGB 2011, model year 2012
expansion valve in VW Polo 6C GTI 1.8 TSI 2015
air conditioning pipes (refrigerant lines) in my 6R 1.4 CGGB
aircon hoses in VW Polo 6C GTI 1.8 TSI 2015

Old type of expansion valve
6Q0820679F (6Q0 820 679 F) / 6RD820679A (6RD 820 679 A)

expansion valve – old vs new:

top → old type
bottom → new type

Left side → evaporator with expansion valve from my Polo 6R 1.4 CGGB 2011: 6Q0820103D (6Q0 820 103 D) including expansion valve 6Q0820679F (6Q0 820 679 F)

Right side → evaporator from Polo 6C 1.4 TDI 2015:
6C0820103 (6C0 820 103) including expansion valve 6C0820679 (6C0 820 679)

New type of expansion valve
6C0820679 (6C0 820 679)

6C0820679
6C0820679
6C0820679
6C0820679
6C0820679
6C0820679
the thickness of the tubes and the metal holder are the same in both evaporators

What is an air conditioning evaporator?

To cool the interior of a vehicle, the air conditioning system has to compress and expand refrigerant, changing its temperature. The air conditioner evaporator is what makes the refrigerant cold. The evaporator is metallic, so if there’s moisture in the air conditioning system, it can cause corrosion. Likewise, a leaking heater core can get coolant on the evaporator, potentially ruining it. Additionally, the rubber seals for the AC lines connecting to the core may cause the evaporator to leak.

new seal (black) vs old seal
6Q0820139 (6Q0 820 139) – old seal
6C0820139 (6C0 820 139) – new seal (black)

Evaporator with expansion valve – photos

Differences in coolant pipe heat exchanger (heat exchanger flange)

Depending on the engine, the coolant hoses are different, so the differences are also in coolant pipe heat exchanger. The ways of fixing the coolant hoses are also different.

If you don’t want to have a double job (like me), it’s best to check before assembling the Climatronic heater that the hoses fit.
If they don’t fit, you will have to replace them – It’s better to do it when the heater isn’t installed in the car yet ; -)

Don’t worry if you bought a heater from a car with another engine. These parts are like LEGO – it’s easy to unscrew them and change parts from
the old heater for manual AC. I had to do that, below you can find some photos.

My 6R with CGGB engine has coolant pipe heat exchanger 6Q0121065N, but Climatronic heater which I bought had 6Q0121065M, so I had to
replace them. Earlier, I didn’t realize that there are so many types of coolant pipe heat exchanger, pipes etc. 😛

To unscrew coolant pipes you need to have M8 triple square bit socket:

XZN 1/2 M8 triple square bit socket, 100MM YT-04352 YATO
6Q0121065N
6Q0121065M

Types of coolant pipe heat exchanger in Polo 6R/6C:

1. 6Q0121065M (6Q0 121 065 M)
➔Volkswagen Polo (2013 – 2014) 2.0 l tr. feed 4-cylinder+ petrol eng.+ CDLJ
➔ Volkswagen Polo (2010 – 2012) 1.4 l tr. 4-cylinder+ petrol eng.+ CAVE
➔ Volkswagen Polo (2015 – 2017) 1.4 l tr. rear diesel eng.+ PR-T0H+0GG
➔ Volkswagen Polo (2015 – 2017) 1.2 l tr. diesel eng.+ PR-TS4
➔ Volkswagen Polo (2015 – 2017) 1.0 ltr. petrol eng.+ PR-TJ4

6Q0121065M


2. 6Q0121065N (6Q0 121 065 N)
➔ Volkswagen Polo (2010 – 2014) 1.6 ltr. 4-cylinder petrol eng.+ automatic+ CLSA
➔ Volkswagen Polo/Vento (2016 – 2017) 1.6ltr. petrol eng.+ PR-G1A
➔ Volkswagen Polo (2015 – 2017) 1.4/1.6ltr. petrol eng.+ PR-TK0,TL0+ G0C
➔ Volkswagen Polo (2010 – 2012) 1.4ltr. 4-cylinder+ petrol eng.+ CGGB,CMAA
➔ Volkswagen Polo (2013 – 2014) 1.4ltr. 4-cylinder+ petrol eng.+ CGGB
➔ Volkswagen Polo (2013 – 2017) 1.2ltr. 4-cylinder+ petrol eng.+ CBZB
➔ Volkswagen Polo/Vento (2015 – 2017) 1.2ltr. 4-cylinder+ petrol eng.+ PR-TW0
➔ Volkswagen Polo (2010 – 2012) 1.2ltr. 3-cylinder+ petrol eng.+ CGPA,CGPB
➔ Volkswagen Polo (2015 – 2017) 1.0ltr. petrol eng.+ PR-TH4+ 9AB,9AK

6Q0121065N

3. 6Q0121065G (6Q0 121 065 G)
➔ Volkswagen Polo (2011 – 2017) 1.4/1.6ltr. manual gearbox, DAHA,CSRA

6Q0121065G

4. 6C0121065 (6C0 121 065)
➔ Volkswagen Polo (2015 – 2017) 1.4ltr. rear, diesel eng., CUSA, CUSB, CUTA, CYZA, CYZB

5. 6Q0121065D (6Q0 121 065 D) 2000-2008

6. 6Q0121065H (6Q0 121 065 H) 2000-2008