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Mon Jun 08, 2009 6:43 pm

So I finally got around to replacing the heater tube on my bus. Just in time for a nice hot summer.

Before all of this my bus would barely make enough heat in the winter to keep my windshield defrosted. And whenever I touched the heater pipe I could hear crunching within the outer wrapping. Pictures for your enjoyment...

So when I unwrapped my original heater tube this basically fell on my head. Its pretty obvious where my heat was going. :(

So the replacement. I used a 2.5" 403 grade stainless steel pipe. I bought a 5' section off ebay for $48 and cut it down to ~50" in length. This gave me just enough length to slide it in both ends of my original pipe. The original was ~2.75" in diameter so this gave reasonable snug, but far from airtight seal.

Once it was in place I placed a few pop rivets in at each end to secure it somewhat.

I then wrapped each end with many layers of Nashua brand 324A "Cold Weather" foil tape. This tape is rated for temps up to 325* Fahrenheit and really the only foil tape I could find with a suitable temp range at home depot.

After than I decided to insulate it by first wrapping it in a 2" piece of fiberglass insulation, and then wrapping that with a piece of Reflectex.

I the taped the reflectex together using the same Nashua tape.

Overall the project cost me about $75 which I think is pretty reasonable and I feel like my replacement is well sealed, insulated and there is no reason why it shouldn't last another 40 years.

Mon Jun 08, 2009 6:55 pm

Wow that thing was toast! Good job, too bad you have to wait a bit to get much use out of it 8)

Tue Jun 09, 2009 6:56 am

Nice job!

Tue Jun 09, 2009 10:43 pm

Just read your posting on your new heater tube. This winter i didn't get the volume of air or the heat that I did last year and there was noise from the right side vent. Tomorrow morning I'll crawl under the camper and squeeze my heater tube and see if it crunches or crackles. I'll bet mine needs replacing also. Thanks for the post, the pictures, and the repair info.
Aloha
tp

Sat Jan 09, 2010 7:27 am

It looks like there will be a lot of squeezing going on, me to after I saw the photos of your heat tube. That will have to wait until summer time.

Sat Jan 09, 2010 10:10 am

Just a suggestion, use stainless steel stove pipe and/or close cell foam insulation, the fiberglass insulation is going to get wet, hold water and rust out steel or even galvanized steel pipe pretty quickly.

Sat Jan 09, 2010 10:45 am

also - that tape has a tendency to loosen with time. Use cable ties to back it up.

Sat Jan 09, 2010 11:05 am

On the farm we have 3" aluminum irrigation piping - i used a section of this and it works great, and keeps the vehicle weight down for efficiency :P

Sat Jan 09, 2010 6:55 pm

rustbus wrote: On the farm we have 3" aluminum irrigation piping - i used a section of this and it works great, and keeps the vehicle weight down for efficiency :P

Nice idea, I may go that route the next time I fix up a heater system.

Sat Jan 09, 2010 7:29 pm

I am kind of at a loss here. My heater tube is like an accordian and runs all the way from the back to the front. It is double walled and is sealed with flexible rubber membranes. The pipe in the photo looks like it was rusty thin wall steel. Do some years have a hard tube instead of a flexible one?

Sat Jan 09, 2010 7:41 pm

SGKent wrote: I am kind of at a loss here. My heater tube is like an accordian and runs all the way from the back to the front. It is double walled and is sealed with flexible rubber membranes. The pipe in the photo looks like it was rusty thin wall steel. Do some years have a hard tube instead of a flexible one?

Earlier models had steel tubing while later ones had the corrugated paper. Both have there failings. :cry:

Sat Sep 01, 2012 7:41 pm

Is there anything inherently dangerous about using standard auto exhaust pipe for a tube replacement?

Sat Sep 01, 2012 7:59 pm

Nope, as long as it fits it works fine.

Sat Sep 01, 2012 8:05 pm

BuckeyeBus wrote: Is there anything inherently dangerous about using standard auto exhaust pipe for a tube replacement?

As long as it isn't hooked up to the tailpipe :)

I'd try to stay with something stainless and avoid anything that melts when wrapping it. The temperature coming off the heat exchangers will melt plastic quickly.

Tue Aug 23, 2016 9:51 am

Heater Tube Replacement

aerosurfer wrote: Wanted to share my new heat tube version I did this week. The old diverter was completely gone, and the whole system was poorly rigged (incompletley at that too) from the P.O.

Cut out a like new diverter piece from a parts bus, and finally got around to crafting it all up.

from the Hardware store I used

Two 3"to 4" aluminum connectors
3" Piece of aluminum ducting, Came as a 5' section
4" flexible dryer tubing
3" flexible dryer tubing
Aluminum tape
Roll of Reflectix

First I only wanted to do this once (in theory) so I made sure to POR15 the underside of the floor and frame above where the tube will be

Then I welded the diverter back into position. The dryer tubing hanging down is the 3" tubing up over the beam to the heater tree in the cabin, partly wrapped in reflectix. The aluminum tape on the intake side of the diverter is to widen the opening as that will receive the 4" end of one of the connectors

With the original fiberglass diaper back in place. Taped and sealed

Now the 3" aluminum tube, cut in the middle to allow it to be snug in both ends

Started wrapping Reflectix in sections over the aluminum pipe

Off the the rear Y pipe I inserted the 3" end of the other connector into it. Once again with Speed tape on the outside diameter of 3" side of the connector to seal and snug it, then forced the other half of the 3" aluminum pipe into the 4" section

I was able to cut it so it was very snug in the gap. This I only used speed tape to seal the sections

On the rear part, the Reflectix slides snugly into the gap of the 4" connector around the 3" pipe. I didnt get a picture of it, but before I put on the other half of the pipe i slid the 4" dryer flex tube over the reflectix as additional insulation and protection. And all sealed up.

I still have some more reflectix to add the front hose, and I have to install and cover the other outlets in the diverter, but I can report the heat is very nice and pretty strong. Elsewhere in the system its sealed , but not perfect off the heater boxes and flappers. I had nothing to compare it to prior (in any bus), but it blows out of the defrost vent very well. I know some have said to delete the diverter junction all together, but it was such a perfect part and I was able to get the forward floor vent tube and a non broken cable for it. Still have to make something or use SCAT tubing for the vent under the rear bed

heater tube replacement solution

Welt wrote:
Before removing the rotisserie, some final things were done down under. Copied the original insulation with aluminized fibreglass fabric and ceramic wool.

Installed everything with aluminium tape and galvanized steel wire.

Tue Aug 23, 2016 10:17 am

That's my write up on the aluminum heat duct and I can say it has held up very well so far. Blows nice and hot.

Also if anyone needs the fiberglass insulating piece on the Y pipe I just listed one in the classifieds

http://www.thesamba.com/vw/classifieds/detail.php?id=1963275

Tue Aug 23, 2016 1:53 pm

My metal guy in Denver replaced the heater tube with a 3.5" stove pipe. It has an inner and outer layer, and insulation between.

Here is the double cab on the rotisserie:

And another pic of the pipe, sealed up:

Sat Apr 01, 2017 12:51 pm

Looks like just the right size

Tue Oct 17, 2017 7:19 am

If you don't mind me asking, what's the length on that stove pipe segment you installed? It looks like one pre-made unit (no cutting visible), so it makes me think it was bought to the correct dimensions.

Thanks in advance!

- Doug :-)

Tue Oct 17, 2017 4:21 pm

I used the exact same piece, bought it right off the shelf at Home Depot. Don't remember the size, but something standard, maybe 4 feet? Grab a tape measure