Installing Bobilvan's CDH water heater

[fxr]

Mrs fxr had her heart set on a fully plumbed in water heater rather than faff about with the Zodi etc. Great, I get to cross off both Christmas and birthday presents. Her choice - the Bobilvan's heat exchanger that works with the CDH. But now to somehow shoe-horn it into the van...

The only space sensibly available was under the seat. With the Zodi gone, the only other bulky item was the 3qt Instant Pot - that can sit behind the rear seat / under the front lip of the bed quite happily.

I had to trim the sides of the heat exchanger's feet to get it to sit properly alongside the tank, but it does just fit. Because I've got a 45l water tank under the passenger side floor there was only one place for the exchanger's air exhaust to get to the outside - three layers of steel to get through!

So far I've just got the hot air system sorted - the rest of the plumbing will have to wait until I get shower fittings etc in the post next week. I'll post again when everything arrives.

The air diverter and exchanger:

The tank just squeezes in:

The hole in the floor:

The gap where the exhaust had to go:

Not a lot of room!

_________________
Jim Crowther
1984 1.9l EJ22 Westy Wolfsburg Edition
Vespa GTS 300

[steve244]

Folks, fxr is not burning babies to take warm showers.

(Google cdh)

This stands for something far more nefarious.

https://www.stokeloafvan.com/blog-1/winter-van-life-chinese-diesel-heater-cdh-review
_________________
82 AC vanagon approx 200K miles (3K are mine).
DD is a 2015 Leaf
Road Trip to Hell (FL 2023)
The Vanagon's drivetrain and chassis restomod thread. Best sung to the tune of I Did It My Way...

[steve244]

OMG I want one! I was seriously thinking about reviving the sleeping gasoline dragon lurking under the floor.

https://nerdtechy.com/best-diesel-unleaded-air-heater

Ferrying the thing back from CA in April we spent the night at 8,000 feet in Great Basin NP. We had a layer of frost on the inside. My son had his electric vest. I had me.

Curse you, fxr!
_________________
82 AC vanagon approx 200K miles (3K are mine).
DD is a 2015 Leaf
Road Trip to Hell (FL 2023)
The Vanagon's drivetrain and chassis restomod thread. Best sung to the tune of I Did It My Way...

[steve244]

But wait! Here's another perspective.

https://www.4wdtalk.com/diesel-heater-buyers-guide/

Not sure now...

I must be adding duplicated discussion.

What's the definitive thread here on diesel heaters?

NM! Found it.

https://www.thesamba.com/vw/forum/viewtopic.php?t=744132

Meh. Think I'll try firing up the ol' BA6. Watch for news of a Marietta Vanagon fire.
_________________
82 AC vanagon approx 200K miles (3K are mine).
DD is a 2015 Leaf
Road Trip to Hell (FL 2023)
The Vanagon's drivetrain and chassis restomod thread. Best sung to the tune of I Did It My Way...

[shagginwagon83]

Cool to see this as mine comes in tomorrow. I know this because Bobilvan is sending me an email every day with shipping information since the package has been sent.

How many water tanks do you have? It looks like a Westy so I imagine you have the 10 gallon original. You mention 45L passenger tank and now you added another?
_________________
Brandon
"Jo Ann" - '83.5 Westfalia EJ22e w/Peloquin
Instagram @joannthevan

[fxr]

The 18l tank supplied by Bobilvans is extra, and will be filled when empty and required by an extra pump from the 45l under-slung tank. Enough for three (maybe four) showers for two - that should last us a couple of weeks.
_________________
Jim Crowther
1984 1.9l EJ22 Westy Wolfsburg Edition
Vespa GTS 300

[shagginwagon83]

My kit came in. Wow, a lot of parts!

I am still thinking through my installation. In your install it looks like you installed the splitter...so either you have heat output or you are heating the water.

I did not buy the bobil water tank. I originally thought I would heat the Westy water tank - but now I am thinking that the tank being inside the van, along with the van heated by heater, will be enough to keep it from freezing.

So now my thoughts are heating the water tank under the van for showers.
_________________
Brandon
"Jo Ann" - '83.5 Westfalia EJ22e w/Peloquin
Instagram @joannthevan

[shagginwagon83]

I messaged Bobil and he does not recommend always having radiator in line of heater.

So do you always have to manually pull the diverter when you want hot water? Along with turning on the switches/controller
_________________
Brandon
"Jo Ann" - '83.5 Westfalia EJ22e w/Peloquin
Instagram @joannthevan

[fxr]

[fxr]

I've got it installed enough to give it a good test - this took a day later than I expected as the Bobilvans instruction booklet had some errors. After much head-scratching and reading the separate controller instructions I was able to figure it out. I don't blame whoever wrote the original instructions - it's all somewhat tortuous.

Tomorrow I'll take photos and write up what I did, together with the gotchas that inevitably cropped up.

Then I'll box it in and call it done.
_________________
Jim Crowther
1984 1.9l EJ22 Westy Wolfsburg Edition
Vespa GTS 300

[steve244]

Pictures whilst showering!
_________________
82 AC vanagon approx 200K miles (3K are mine).
DD is a 2015 Leaf
Road Trip to Hell (FL 2023)
The Vanagon's drivetrain and chassis restomod thread. Best sung to the tune of I Did It My Way...

[fxr]

It's finally in - all except for the panel mount quick-connect that the shower will eventually connect to, which won't be here until late December.

Notes on the install that will apply to anyone else using this system:

1. The Bowden cable supplied to operate the diverter cannot easily be shortened to a more convenient length, and is very stiff. I will eventually use or make a different solution - probably a servo.

2. The installation calls for a 26mm hole cutter to mount the bulkhead connectors - a 1" hole cutter for wood works just fine. That leaves a slightly tight hole, but a connector will screw into it with ease.

3. The supplied PTFE tape to wind around the 1/2" to hose barb connectors - this isn't good enough to give a good seal, as the 1/2" threads aren't tapered. A smear of 'blu' pipe thread sealer does the trick though - we don't want the slightest hint of weeping connectors inside our vans!

If using this for a shower, make sure you get a shower head that has a mechanical Stop/Go button to stop the flow. The pressure switch will then stop the output pump.

Here's page 11 of the install notes, with my solutions to the errors on the original page:

Note the water and air temp sensors need to swap positions, and ALL the temperature settings are wrong.

I added an extra pump between the under-floor 45l water container and the tank - this is controller by a removable keyswitch to prevent it inadvertently being switched on.

If using a CDH with Afterburner controller, use the output of the water temp relay (the link in the diagram above) to control a relay to provide a connection between the digital 1 GPIO input of the Afterburner and its ground. Then set the Afterburner GPIO 1 to MaxPwr. Then when the system is switched on, the CDH will fire at maximum as long as the set water temperature is below 40C (or whatever) and switch off as soon as the required temperature is reached.

Some more pictures:

_________________
Jim Crowther
1984 1.9l EJ22 Westy Wolfsburg Edition
Vespa GTS 300

[fxr]

It's now boxed in and tested, pics tomorrow. It takes about 25 minutes for the 2kW CDH to heat 18l of water at 18C to 40C. The first 6 minutes are taken up with getting the hot air (as measured by the probe) up to 70C - then the circulation pump kicks in.

That shower head works really well. It's 'permanently' connected at the moment, with a long wait until the quick-connect arrives.

Next up - our rig for inside showers.
_________________
Jim Crowther
1984 1.9l EJ22 Westy Wolfsburg Edition
Vespa GTS 300

[shagginwagon83]

Awesome job. Very cool use of the GPIO on the Afterburner.

Sorry again, but can you explain the relationship between the 45L and the 18L tank? Do you pump water from your 45L tank into the 18L tank. Then the 18L tank is what you use for shower?
_________________
Brandon
"Jo Ann" - '83.5 Westfalia EJ22e w/Peloquin
Instagram @joannthevan

[fxr]

[Corwyn]

Here's my setup:

_________________
'90 White Westy ("The Longship")
FAS Gen V 2.0
The Annual Baja Rally
https://www.thesamba.com/vw/forum/viewtopic.php?t=604813&highlight=baja

"If anything's" gonna happen, it's gonna happen out there"
~ Captain Ron ~

[shagginwagon83]

^ you’re gonna both have to post a video to truly compare.
_________________
Brandon
"Jo Ann" - '83.5 Westfalia EJ22e w/Peloquin
Instagram @joannthevan

[fxr]

[fxr]

So onto the inside shower rig. I used some of the components we use for showering outside. The main ingredients: a dog's pool, a length of 1/2" irrigation tubing and some 1/2" PVC pipe fittings.

It finishes up like this:

The curtain is hung from the H-bar and also supported by an upright anchored on the front of the upper bed support:

I tried the whole system out - it works beautifully! So now we can have showers when it's inclement weather such as rain, snow, f-f-f-cold or just windy outside.
_________________
Jim Crowther
1984 1.9l EJ22 Westy Wolfsburg Edition
Vespa GTS 300

[fxr]

I've a couple of small improvements to make to the tank - a float switch to shut off filling, and an elbow at the outlet for the shower pump to enable the last bit of hot water to be used as otherwise there's an inch left.

edit - added the elbow:

This shows how I cut down the overflow bulkhead connector to get maximum amount of water in:

I added a plastic box from Tap Plastics to just fit next to the tank to accommodate the showerhead when still wet:

_________________
Jim Crowther
1984 1.9l EJ22 Westy Wolfsburg Edition
Vespa GTS 300