No heat from heater

clacker

Veteran Member
Joined
Mar 29, 2000
Location
Oxford Mills, Ontario, Canada
TDI
2015 Golf Wagon TDI DSG Trendline, 2000 Jetta TDI auto, 2008 Mercedes R320, 2006 smart fortwo cdi
2015 sportwagen tdi dsg base model. 12k miles
11/17 delivery date
No heat on cool nights it fine all winter but now seems stuck on cold. Playing with the heat dial on longer drives back and forth cold to hot will get some heat but nothing close to hot. Ideas? Is there a way to watch the dial in VCDS and confirm data? So far selling dealer has been nothing but 2hours wasted round trips. Doing my research first
 

Mrrogers1

Veteran Member
Joined
Jun 25, 2006
Location
Omaha NEEEBRASKA
TDI
2011 Golf TDI 6MT, 2011 Jetta TDI DSG, 2015 Golf Sportwagen S TDI DSG
2015 sportwagen tdi dsg base model. 12k miles
11/17 delivery date
No heat on cool nights it fine all winter but now seems stuck on cold. Playing with the heat dial on longer drives back and forth cold to hot will get some heat but nothing close to hot. Ideas? Is there a way to watch the dial in VCDS and confirm data? So far selling dealer has been nothing but 2hours wasted round trips. Doing my research first
I don't know if it's an "official" TSB out but the heat core clogging is rather common for the MK7's and will be covered under warranty, I think, in most cases. The early version of the cores had smaller ports or something so the part was revised. I had mine done in the winter and it was hard to tell at first because we have an aux heater system in the car that ONLY serves heat to the driver side of the cabin. A sure way to know if the core is clogged is if you have "pretty hot" air on the driver side and ice cold on the passenger vents.
 

sloinker

Veteran Member
Joined
Jun 27, 2015
Location
Casper, Wyoming
TDI
'15 Sportwagen '15 Golf Hatch
I don't know if it's an "official" TSB out but the heat core clogging is rather common for the MK7's and will be covered under warranty, I think, in most cases. The early version of the cores had smaller ports or something so the part was revised. I had mine done in the winter and it was hard to tell at first because we have an aux heater system in the car that ONLY serves heat to the driver side of the cabin. A sure way to know if the core is clogged is if you have "pretty hot" air on the driver side and ice cold on the passenger vents.
Do the '15 S sportwagens have the auxiliary heater? My '15 Passat SE did and was noticeable on cold mornings. My sportwagen not at all. I looked through the owners manual and it didn't mention the aux heater. I'm thinking there isn't one.
 

Mrrogers1

Veteran Member
Joined
Jun 25, 2006
Location
Omaha NEEEBRASKA
TDI
2011 Golf TDI 6MT, 2011 Jetta TDI DSG, 2015 Golf Sportwagen S TDI DSG
Do the '15 S sportwagens have the auxiliary heater? My '15 Passat SE did and was noticeable on cold mornings. My sportwagen not at all. I looked through the owners manual and it didn't mention the aux heater. I'm thinking there isn't one.
I "believe" there definitely is but I can't say that I personally tore it down to check. The symptoms and all line up to say it does BUT maybe the core was just clogged and not sending to the passenger side in my case and it made it appear and manifest itself like the other MK7's that had the issue.
 

clacker

Veteran Member
Joined
Mar 29, 2000
Location
Oxford Mills, Ontario, Canada
TDI
2015 Golf Wagon TDI DSG Trendline, 2000 Jetta TDI auto, 2008 Mercedes R320, 2006 smart fortwo cdi
Pretty positive Canadian Sportwagen sales brochure mentioned the grid heater. I know the last 2014 did have it. Thanks for the input so far. I will try vagcom this weekend and see what sort of inputs I can read
 

dataiv

Veteran Member
Joined
Feb 12, 2005
Location
Ottawa, ON
TDI
2015 Golf Wagon TDI 6MT
The 2015 does not have an electric aux heater. I checked the coding in VCDS on my car and the box(es) relating to Aux-Heater are unchecked. On my old 2011, they were checked. I think this is due to the coolant circuit differences with the EA288 engine, the intent is to provide heat more quickly with the really short coolant circuit for just the heater core. I don't know how well this works in practice, though!

Also can't say I used the 2011 aux heater often, there only were a few times when the inside windshield was iced up and I used it and idled for a while until it started becoming possible to see out the window ;)
 

franklinstower

Veteran Member
Joined
Dec 16, 2005
Location
Kirkland, WA
TDI
'15 gsw 6mt wagon
A/c stuck on?

I just noticed mine (14k miles) seems to be stuck on a/c.
I have a/c off, it's 80° out and wanted to have just the fan running with no A/c, however it's still frosty cold..... I've cycled the a/c button a few times to no avail....?
 

740GLE

Top Post Dawg
Joined
Aug 19, 2009
Location
NH
TDI
2015 Passat SEL, 2017 Alltrack SE; BB 2010 Sedan Man; 2012 Passat,
one thing I notice on our Alltrack if it's pulling in "fresh air" with no AC and temp setting on stone cold, the vent temps are 20-30F higher than ambient, I think the cabin air intake on the Mk7 is pretty poor in design and lost of engine heat soaks it.

If you are having any sort of coldish air when it's 80f out, somethings stuck with the AC system.

if you have VCDS you should be able to log the AC system to see what is being commanded. Might be a stuck RCV?
 

Mike in Anchorage

Veteran Member
Joined
Jan 4, 2009
Location
Anchorage, AK
TDI
2016 Touareg Lux, 2015 Golf Sportwagen SE, new 4 Sept 2017;2009 VW Jetta TDI Sportwagen (Ruby) sold to VW on 22 SEP 2017
An easy check for the electric auxiliary heater is if you have an 80 amp fuse installed. My 2009 had it. I haven't checked the 2015 yet.
 

GreenLantern_TDI

Veteran Member
Joined
Feb 27, 2014
Location
Iowa
TDI
2015 GOLF SEL
I would love to have an aux heater like my 06 did. The MK7s windows fogged alot last winter and its a bad deal leaving work.
 

jason_

Veteran Member
Joined
Jun 2, 2014
Location
michigan
TDI
2015 s wagon dsg
The 2015 does not have an electric aux heater. I checked the coding in VCDS on my car and the box(es) relating to Aux-Heater are unchecked. On my old 2011, they were checked. I think this is due to the coolant circuit differences with the EA288 engine, the intent is to provide heat more quickly with the really short coolant circuit for just the heater core. I don't know how well this works in practice, though!

Also can't say I used the 2011 aux heater often, there only were a few times when the inside windshield was iced up and I used it and idled for a while until it started becoming possible to see out the window ;)
My15 s trim wagon does have a grid heater.

A clogged heater core will show itself once block is up to temp and grid heater stays off.

Or disable it in vcds.
 

The Tortoise

Veteran Member
Joined
Apr 24, 2017
Location
Ottawa
TDI
2015 GSW Trendline - White
My15 s trim wagon does have a grid heater.
Within 2 or so minutes of only idling (fan set 3+, defrost and full hot) I am getting warm/hot air coming from the vents.

That a good sign I have the heater? I forgot to check when I had borrowed a friends OBDEleven.
 

jason_

Veteran Member
Joined
Jun 2, 2014
Location
michigan
TDI
2015 s wagon dsg
Easiest way to check


If it's enabled in coding

Ice cold car. Max heat. Slowly turn fan to 6. I don't think 5 and lower will trigger it.

You'll probably hear a click, then ecm will bump rpm to roughly 1k to spin up alternator for winding cooling


When I was playing with it, bouncing speeds 5 and 6 will trigger the grid heater condition, but the coolant has to be below 50c/150f? Something like that.


Sent from my 2PS64 using Tapatalk
 

C C

Well-known member
Joined
May 23, 2015
Location
USA
TDI
GSW
I'm sure my 2015 has a grid heater. With the heat setting on maximum hot, the heater fan pumped out heat for 30 minutes with the engine off. Then the battery was too weak to start the engine. Luckily, the incline was steep enough that it kick started in reverse.

That's when I noticed the idle speed was higher with heat set on max, to increase the alternator output for the electrical load. A/C comes on automatically with dial set at minimum, aux heat is triggered with the dial on max.
 

ticaf

Veteran Member
Joined
Nov 15, 2018
Location
US Mid-Atlantic
TDI
Stock 2015 Golf SW S Manual TDI
Sounds like a thermostat stuck open to me.
The 'clutch' on the water pump has minimal effect and is not the issue here ( typically causes overheating rather than engine running cold)
 

thundershorts

Top Post Dawg
Joined
Jul 15, 2010
Location
west chester pa
TDI
2015 passat tdi sel premium 2015 golf s tdi gls tdi b5.5, 2002 eurovan,Peugeot 505 td,Citroen cx25 prestige
As to grid heater, I set the temp knob to max heat, set fan to 6 and fan speed dropped to mid-low speed and I had heat coming out vents in less than a mile. After 3-4 miles fan speed increased up to normal high speed. Apparent my car has aux grid heater and the fan speed reduces automatically so you get some heating until water temp is sufficient. Outside temp was 27f. I would never have known about this feature till It was discussed here.
 
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