Heater works... ALLLLLL the time

[Colonel_Brown]

Hey all,

I've been putting off fixing a problem with my van for a while now. Hot air is always coming out of my heater vents when I drive. Turning off the blower, closing my vents and rolling down the windows had "solved" my issue while I tackled my bigger to-do's but having the heater on in July is really starting to suck now...

My guess is that I need to stop coolant from getting into the heater core, assuming I'm right on that part(?) here are my questions:

1) Are one of those slider climate controls supposed to shut off coolant flowing to my heater? (I looked at some posts/diagrams online but I can't figure out which switch should turn OFF the heat!)

2) If my problem isn't a broken slider/switch what else could be making my heater stay on? I assume there is some valve that stops coolant from going into the heater? Where is it?

Thanks everyone!!
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'84 Vanagon GL (1.9L) - "Colonel Brown"

[Homercules]

I just finished replacing my front heater control valve. Not sure if it has fixed the problem yet as my old valve seemed fine when I tested it. There is still some heat getting through but I don't know how bad until I get it on the road. I have read that it sometimes does and sometimes doesn't fix the problem. Might have to install a ball-valve shut-off if it continues to be a problem.

FYI Buy proper hose clamp tool! I removed the clamps with pliers but couldn't get it back together. Bought the tool and put it back together in 30 seconds.
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89 Syncro

[OhChit]

I was having this problem with one of my Vanagons. So I replaced the front Heater Valve located behind the Radiator and Fan. It didn't solve the problem. I was stumped why I was getting heat even with my slider Valves shut off.

Oddly enough sometime afterwards I noticed that my swill Pot water tank keep showing slightly low on water, while my overflow tank behind the tag door never seemed to change water levels..

I found that my heat problem was due to the blue cap on my water fill Tank. Apperently it wasn't releasing the water preasure from the engine and when it heated up the preasure was forcing hot water pass my shut off valve and through my heater. Strangely enough when I replaced the Blue Cap, the probem went away, I also began to see a fluid change in the lower overflow tank.

Note.. another strange thing that I've seen is that the cable behind the dash slider level can get kinks on cables that gets dried out or not used much, thus not fully shutting off the heater valve. If your heater slide lever moves real easily, you probably have a bent cable, and it's not actually moving the heater control valve.
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Fast Cars, and Slow Women Makes me DrooL.

[debbiej]

we too replaced the front heater valve. make sure the knobs are actually closing the vents off. we also used foil tape to tape off the heat vents during the summer.

[Homercules]

I hadn't thought of overpressure of the coolant... Definitely something to check and replace blue cap if necessary. I wonder if another valve acting as a pressure reducer would also work? (For those of us running an engine conversion and possible non-stock pressure).
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89 Syncro

[phatveedub]

Look here:

http://www.thesamba.com/vw/forum/viewtopic.php?t=237271&highlight=front+heater+valve

Installing a ball valve in the front heater line (like the photo) will completely isolate the front heater. Works like a charm...

[funagon]

I had the same problem with my heater on all the time. In my case it was the slider heat control was not firmly attached to the cable that controls the heater valve. Pull out your ashtray and maybe your stereo and look at the cables that those controls push and pull.

The cable runs through a housing (like a bicycle cable). If memory serrves me correctly it was a clamp bolted to the housing which had come loose. Because the housing was able to move with the cable there was no temperature control possible. I hope that's all your problem is because its a pretty easy fix to tighten the bolt back into place.
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1990 GL 7-passenger
2.2 liter WBX

[dobryan]

If you take out your spare tire from under the front you can look up and see the valve action while someone slides the shutoff valve to make sure it is closing all the way, if it is and you are still getting heat to the front heater core then the next thing is to replace the valve or add one of the ball valve shutoffs.
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Dave O
'87 Westy w/ 2010 Subaru EJ25 (Vanaru) and Peloquin TBD

"To travel hopefully is a better thing than to arrive." Robert Louis Stevenson

MD>Canada>AK>WA>OR>CA>AZ>UT>WY>SD
https://www.thesamba.com/vw/forum/viewtopic.php?t=620646

Building a bus for travel in Europe (euroBus)
https://www.thesamba.com/vw/forum/viewtopic.php?t=695371

The Western Syncro build
https://www.thesamba.com/vw/forum/viewtopic.php?t=746794

[Colonel_Brown]

Thanks for the replies everyone, you guys rock!

I took a look around and found that when I move the heater control to blue (heater OFF) it add slacks to the cable but the valve arm doesn't move. When I set the heater control to red (heater ON) the cable tightens up but nothing happens on the valve.

So I just want to understand how the system SHOULD work... Is the heater valve supposed to have a spring or something so it closes itself when I slack off the cable?

Thanks again.

Me...

New...

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'84 Vanagon GL (1.9L) - "Colonel Brown"

[Terry Kay]

No spring assist.
The valve is on the cable & it's retaining clip alone---

Most folks have been installing a remote shut off valve in the back of the Van--before & prior to both heater's.

Good idea--then it's all off for the summer.
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T.K.

[Wildthings]

The cables get all screwed up behind the dash fascia. Once the cable bends it will not work the valve. The heater control has not worked at the time of purchase on any of the Vanagons I have bought for my own use, so this is a very common problem.

This is what the heater control cable looks like stock. Note that it has been bent and kind of restraightened.

This is what it looks like after I do my modification to keep it from bending again.

Just shorten the inner cable, snug the adjustment up on the sheath, and bend the brackets slightly to get better alignment.

[shenan-agon]

[DubNuts]

If your going to open / disconnect your Heater Hose to replace the front Shutoff Valve.. You may want to consider everyones suggestions now and install a Ball Valve Shutoff in the engine bay. Just simply locate your Hot Heater Supply Line and install it there.

I just recently installed one in my heater Supply line. I went to Homedope and picked up a 1\2" PEX Ball shutoff Valve it was like $10.00.. It worked out great, it is made of Brass, and is pre made with Hose Type Barbs on both ends. It fits great inside of the Vanagon Heater hose. This simple upgrade shuts off Hot Water Heat going to both Heaters so no more radiant Heat. Please keep in mind that the Shutoff Valves on both the front and rear heaters even if they are working correctly only stops the heat from going through the heater Core but as with the rear heater the hot water enters the rear bench seat area and continues to add heat to the Vanagon.

To make your life easier you may just want to consider installing just the new Engine Bay Ball Valve and leave the others alone. This would save you lots of work, as getting to the front Heater Valve isn't as easy as it 1st looks. If you do decide to mount the Engine Ball Valve be sure to support the Valve weight cable tie etc so it doesn't sag, pinch, tear your hoses, etc.

BTW.. your need to bleed your water system once you open your water lines. So start doing a search on how to purge the air and Bleed your cooling system. Hint be sure that all of your heater valves are open while your bleeding the air out of the Coolant system. Once your done and if you add the engine bay Ball Valve, all your simply have to do is shut that Valve off to stop any Hot water from flowing to the Heaters.. Then open it again when your ready for cool weather driving / use.