heaters not blowing hot air, cold air only

[tranmx2]

This got to be due a resurrection so here it is

Got similar issue. Engine gets up to temp, console knobs don't work but they do turn directly on the heater box in driver's footwell. Srill onlt blows cold.

What are the two pipes winter mentions to check to see if circulation is actually taking place? The two at rad, one going to it which gets hot when engine up to temp and stat opens and the one leaving rad?

If both hot I have circulation yes?

Sent from my SM-G991B using Tapatalk

2012 Mk7 2.2 RWD.
From the lhs of the Thermo a pipe goes to the EGR cooler and then to the cab heater.
The bypass:
Inside the thermo housing behind the thermo is a plug with a hole in it. The bottom of the thermo sits on this plug. Behind the plug is another sprung plug which loosely sits in the front plug - flow reducer.

The coolant from the eng' flows into the rhs of the thermo and out the lhs to the EGR cooler and cab htr.
When the coolant gets hot the thermo opens away from the front, coolant can flow to the rad and to the bypass and so to the inlet of the coolant pump.
A displaced plug or a stuck open thermo can have the coolant circulating from the eng' to the pp (bypass) and to the eng and not going to the cab heater.

The spring on the sprung plug was broken on mine.

[knobby1]

2012 Mk7 2.2 RWD.
From the lhs of the Thermo a pipe goes to the EGR cooler and then to the cab heater.
The bypass:
Inside the thermo housing behind the thermo is a plug with a hole in it. The bottom of the thermo sits on this plug. Behind the plug is another sprung plug which loosely sits in the front plug - flow reducer.

The coolant from the eng' flows into the rhs of the thermo and out the lhs to the EGR cooler and cab htr.
When the coolant gets hot the thermo opens away from the front, coolant can flow to the rad and to the bypass and so to the inlet of the coolant pump.
A displaced plug or a stuck open thermo can have the coolant circulating from the eng' to the pp (bypass) and to the eng and not going to the cab heater.

The spring on the sprung plug was broken on mine.

He doesn't have a Euro-5 RWD....they're a different setup to all other Mk7 2.2's.

Lord Knobrot

[Brettbear63]

Hi , ive just had my EGR valve changed and now my heater only blows cold air , it worked fine before the change , there is hot water in the expansion tank and all the pipes from the rad to the tank are hot, it doesnt have air con , it is a mk7 2.4 rwd 2009 tdci , should they have bled the system , van runs ok but tickover seems a bit high

[wojciech]

Check that the water pipes connected to the heater valne on the engine side are warm. Whether the valve is open or closed, fluid should always circulates through these tubes. If the wires going to the valve are warm, and from the valve to the heater are cool - the valve is not working properly, it closes when the engine is started. If all four pipes connected to the valve are cold, I think they have air or the heater as well.
The valve is located in the engine compartment under the windshield on the driver's side.

[Brettbear63]

Check that the water pipes connected to the heater valne on the engine side are warm. Whether the valve is open or closed, fluid should always circulates through these tubes. If the wires going to the valve are warm, and from the valve to the heater are cool - the valve is not working properly, it closes when the engine is started. If all four pipes connected to the valve are cold, I think they have air or the heater as well.
The valve is located in the engine compartment under the windshield on the driver's side.

The garage left the hose clamps on the EGR pipes , so problem sorted , thank you

[wojciech]

The garage left the hose clamps on the EGR pipes , so problem sorted , thank you

Have you paid for another professional repair?

[Brettbear63]

The garage left the hose clamps on the EGR pipes , so problem sorted , thank you

Have you paid for another professional repair?

I work away from home with it on nights mon-fri so the weekend is taken up with trying to maintain the house , grandkids , , family etc , spending the day under the van after trying to source the part isnt possible , and as i live in it while im away , i have to have it back running every monday at 09.00 am , so the garage has it on a friday afternoon to do any fixes , they dont work weekends . been doing this for 5yrs and hate every minute of it .

[Brettbear63]

Anyway , we took it for a 140 mile roundtrip to North Devon and it goes like a scalded cat and the heater works just fine