The Type 2 Heating System Explained...
My apologies in advance if this is a long scrolling page... it's a long
scrolling topic!
I refuse to drive anywhere wearing four pairs of socks, thermal undies, three jumpers and a woolly hat. That's why one of
my first priorities when we bought Daisy in 1998 was to get her heating
sorted. None of it worked, so all of what follows is based on extensive personal
experience. The reason why many people are so confused about this subject is
that many vans are bought without an owner's manual and neither the Haynes
nor the Peter Russek VW Transporter
manuals go anywhere near the amount of detail required for the average home
mechanic to figure this out. In fact, most garages haven't the faintest idea
how the heating in an air-cooled beetle or van works - so be warned: you will
be paying their hourly rate for them to teach themselves how!
- How it is supposed to work
- The dashboard heater
controls
- The heater cables
- Common problems
In principle...
it works like this. Air is circulated around the
heat exchangers which warm the air from heat off the exhaust manifolds. It is
pushed towards the cab by both air pressure and at least one fan. That's it!
The diagram shows how...
However, please note that your van will be best served with an exhaust
system that retains all of the above components, and performance of your
van's heating will be best improved using original equipment. I know that
normally means 'more expensive', but the best things in life aren't cheap but
they're worth it!
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This is the fan, situated either on top of your engine if you have a
1600 or at the back if you have a 2ltr. They both do the same thing - suck
the cold air which enters the engine bay from the rear body air intake
vents, and blow it via a pair of concertina tubes into your heat
exchangers. If your fan is broken or has broken
blades or if the shroud is poorly fitted not only will your engine not be
properly cooled, but your heating will suffer.
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 The
heat exchangers look like complicated exhaust boxes and when I bought some
for my first beetle back in the early 80's I hadn't the faintest idea what
these bloody expensive boxes were all about. Well they're dead useful - the
cool air from your fan is blown into them and circulates around an
arrangement of fins heated via the red-hot exhaust manifolds. The air is
then ejected out of the heat exchanger into the heater elbow. If your heat exchangers are rusted through anywhere, your
heating will suffer.
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 The heater elbow is simply a
mechanical valve which, when opened, allows the hot air from the heat
exchangers to pass into your van. On the 2ltr engine the elbow is a
separate part, on the 1600 it is integral to the heat exchanger. As
illustrated in the diagram at right, when the valve is closed, the hot air
simply escapes outside. The internal hinged flap is operated via a solid
cable attached to the heater controls on your dashboard - more about them
later. If the hinged flap in either heater elbow is
rusted into position or just plain broken, your heating will suffer.
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When the hot air reaches the central collector it is sent two ways: to
the front of the van and to the rear via three small rear-facing vents on
the floor between the two bulkhead halves. To my knowledge there has never
been any lever to manage the flow of hot air to these vents, so on my van I
have simply blocked off the tube that feeds these vents as, when I am
driving, I want all the hot air in the cab. However, if you
regularly take passengers, especially children, you may find these vents
useful, but be aware that they are largely ineffective as you would require
an additional in-line fan (or something similar) between the heater elbows
and the collector to generate the amount of air pressure to heat the rear
of the van to any noticeable extent whilst also heating the cab.
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This is the wonderful bit, according to my wife! These are the two hot
air vents located behind the kick panels (which should have pre-cut holes
to fit around them) which keep our feet toasty warm even in the coldest
weather. The vents are operated by a lever on the dashboard - more about
that later. There's also a manual slider on the heater tube that allows you
to direct even more hot air into the cab floor. Remember, hot air rises, so
if you have it all blowing onto your feet, it'll eventually get to your
face too!
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Finally, the rest of the hot air exits via two pairs of vents in the top
of your dashboard. Yes, contrary to popular opinion, they really do work!
They are excellent windscreen de-misters and cab heaters. My Daisy has done
almost 110,000 miles and is 27 years old and the last 30,000 miles has kept
me warm in the worst weather. I've also been in the fortunate position of
being able to regulate the heat because all the controls are now working,
so I don't bake in the summer!
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The dashboard heater controls
On your dashboard you have three levers, two with a red knob, one with a blue one.
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This blue lever is the cold air control to the windscreen and the
fresh air ducts at the far left and right of your dashboard and has
absolutely no effect on your heater controls. In fact with this control you
can have cold air blowing on your face whilst having hot air blowing on
your feet. If this control doesn't work (top is closed, bottom is open),
contact me and if there's enough demand I'll do a section on that.
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The left red lever pulls or pushes two solid cables (connected
via a clamp under the dash) that control both heater elbows simultaneously.
When you pull the lever down you receive progressively more hot air, which
you can then further control using the right red lever.
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The right red lever pulls a short cable down to a flap set into
the hot air riser tube down by your feet, allowing you to open or close the
cab kick-panel vents (number 5 in the main diagram). Due to the way the
levers are fitted, this one can only be moved down when the left one is
also down, but if you think about it, this is perfectly logical Wolfsburg
thinking!
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The heater cables
 The
heater cables are a bugger to get to underneath the dash, especially if you
are 6'1" and 18 stone and no good at Houdini impressions! However, I did
it, so I guess you can too. The cable inners are connected to the heater
control levers via the loop in the top of the cable (see diagram) and a circlip to hold them in place. When fitting these cables do
not put any kinks in them - they are solid cable, not braided, and any kinks
will make them difficult to operate once fitted!
All three cable outers are clamped to a bracket
under the dashboard. If this clamp is missing you can almost forget your
heater controls. It is imperative that under normal operation the cables are
securely clamped in place. I tried various methods (mostly unsuccessful)
until I was able to source a clamp from a VW breaker's yard which, 12 months
later, is still in place.
It really is best to do the rest of this job with the van up on blocks or
axle stands as, unless you have a radically raised baja
van, there simply isn't enough ground clearance to get all of these jobs done
properly. If, however, you are 4' tall and weight 6 stone, you could do it
without the above (but how you got that driving licence, junior, is beyond
me)!
When fitting new cables, note the precise route the originals took behind
the kick panels and through the cab floor as this will make it far easier for
you to fit the new ones. You will have to remove the stone guard underneath
the cab to get to the main cable guides. These carry the cables to the rear
of the van right to the heater elbow operator levers, and this bit is a doddle.
 Once
the ends of the cables have been fed through the guides, you have to feed the
end of the cable through the heater elbow lever. It is best to do this with
the concertina heater tube removed (see main diagram - just forward of the
elbow) as this will allow you to determine where, eventually, to clamp the
cable. It is easier to do this with two of you, but I did it on me own just
to be awkward! Pull the left-hand heater control all the way to the bottom,
i.e. in the full on position. Then get back underneath the van. Insert
the clamp screw into the end of the heater elbow lever and feed the end of
the cable through the clamp screw. Now, with one hand, pull the heater elbow
lever until the flap inside the elbow is in the fully open position,
and with the other hand (obviously grasping the appropriate
screwdriver/spanner) tighten the screw clamp, making sure that the cable is
fully pulled through and straight.
 Note: some
people have mentioned that their newly supplied cables weren't the right
length. I found this to be the case as well, although the part numbers were
definitely correct for my year. In my case I just snipped off the metal
moulding at the end of the cable and tightened the clamp screw around the
cable itself. The most important thing is that, with the other end of the
cable firmly clamped at the dashboard end, the cable outer cap at this end is
between the end of the cable guide and the furthest forward movement of the
elbow lever. Make the clamp screws part of your routine checks - you'll thank
me for mentioning it!
Now return to the cab and move the lever fully into the up position
and, underneath the van again, check that the flap is in the closed
position. Depending upon the snug fit of the cable, there may be a slight
gap, and this will mean that there may be a trickle of warm air into the cab
when the lever is up. This is where you play around with small adjustments to
get it just right. Now do the other side and that's your heater controls set
up. The only way to test it is to run the van (or fit a reverse blow vacuum
cleaner to the system to blow air through).
Finally, there is the short cable that controls the footwell
heater vents. This is going to be difficult, not because it's a pain to fit,
but because it's going to be nigh-on impossible to source a new cable. I
still haven't managed to get hold of one two years later, so don't hold your
breath. However, I have simply locked the flap inside the heater tube in the up
position so that whenever I turn my hot air on it hits my feet first (this
suits both me and Dannie just fine). The cable itself, if you manage to get
hold of one, appears to be simple to fit - nothing as complicated as the other
two, so at least that's a relief!
Common Problems resulting in poor or no heating
I have either experienced the following problems myself or have helped
friends discover them in their own vans. They can result in poor or no
heating at all in your van - get them sorted and you'll have a much warmer
journey:
- Non-standard exhaust set-up
- After-market, 'cheap' heat
exchangers
- Broken fan or fan blades
(will also affect engine cooling - sort it now!)
- Poorly fitting fan shroud
(will also affect engine cooling - sort it now!)
- Rusty heat exchangers
- Faulty/rusted heater elbows
- Punctured, broken or clogged
heater tubes
- Heater cables not attached
to control levers
- Heater cable clamp under
dashboard faulty or simply missing
- Heater cables seized in
chassis guides
- Heater cable clamp screw
loose or missing
- Heater cable snapped
I hope this article helps some of you prevent frostbite this winter!
Frank Wognum
Ta ra!
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