Espar B4 Gas Auxiliary Heater Install for Syncro Weekender

[BCgee]

Received my Espar B4 gas heater in the mail this morning just as us Northern Rockies folks are expecting our first snowstorm of the Fall! Luckily I just finished building out an auxiliary battery system and now have a power source ready.

(see this thread at the end for the final aux battery system: https://www.thesamba.com/vw/forum/viewtopic.php?t=...;start=60)

Living in SW Montana and being a winter outdoors nut with a growing family means comfortable and reliable heat is a priority. It’s hard to entice the wife and 1 year old to spend time skiing or belaying ice climbs if there isnt a cozy base of operations... For this reason we did the high top conversion last spring and several insulation, soundproofing, and mechanical upgrades this summer.

I decided on the Espar B4 gas heater because I have a Weekender without a propane tank and typically use my rafting kitchen kit to cook outside 99% of the time it’s needed. The turn-key nature of only using one primary fuel source for both travel and comfort was very appealing; throw on two rotopax for peace of mind and off we go, you get the idea. The B4 can also be adapted to elevation with an sensor, which is important for us living at 5k and traveling to 10k regularly. The economical dimensions of the B4 was the last key factor: the auxiliary battery takes up space under the passenger bench and I’ve kept and use the stock rear heater, luckily the B4 fits comfortably under the bench seat, drivers side.

I’ve done a poor job of contributing to The Samba braintrust even though it’s been a critical resource for me since purchasing our Syncro. The hope is to share my work on the B4 install to help others contemplating the project.

With that said I’ve never installed an auxiliary heater nor an Espar unit, so if anyone has advice on the install or has experience with the B4 install in particular, please share here!

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1987 SVX Syncro Hightop

[MarkWard]

Hello, search my gallery for some pictures of my Espar install in the same location. I spent a weekend deciding where to cut the floor for the intake and exhaust.

Perhaps the above will save you some time. Sorry did not record the measurements. I also bent up an insulated cover to protect it.
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☮️

[Steve M.]

I thought that the latest models of the B4 have the altitude sensor built into it?

Or maybe I'm thinking of the Webasto petrol heaters?
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This free advice is worth exactly what you paid for it.

There are seven days in a week. Someday is not one of them.

[BCgee]

[BCgee]

[owokie]

The altitude sensor wiring is a non-issue. That said, you could also run the high altitude pump instead, which I would do if starting from scratch. All you'll lose is a small amount of BTU which is not a bad thing as the B4 is oversized for the Vanagon task. The smaller pump means you're less likely to go into idle mode if you run it overnight, and the mandatory run-up to boost after being at idle is one of the few flaws of this unit. This opinion comes from ~300 nights camping in a B4-equipped full Westy with the top always popped at night.

You are correct that the new B4L does have integrated altitude compensation, the B4 does not.

You're gonna love it.

[BCgee]

[erste]

Espar sells a different high altitude fuel pump, but I searched and don't see one that works with the B4.

This is the one for the D2/D4 however:
https://esparparts.com/fuel-metering-pump-high-p-25174.html

The high altitude kit doesn't include a fuel pump.

I have a D2 with the high altitude kit. I'm using this intake silencer for a Webasto but will work on the espar intake too. I also have the external temp sensor though it's not really needed.

My install:
https://www.thesamba.com/vw/forum/viewtopic.php?t=666522&start=52

I really like having a vent at bed height. I have the same controller as you, and it will display fault codes. Took me a while to figure that out. Only thing I want now is a second controller up front so I can turn the heater on while driving and also see what the temp is in the van.

I didn't want to spend $250 on the high alt. kit either, but in the end I'm glad I did. At altitude in the cold is where you're going to need the heater to work.

[BCgee]

[vwwestyman]

From what I read when I was installing my D2 in my '78 Westy, the high altitude sensor changes the fueling rate of the stock pump (I believe by slightly fewer pump strokes) when at high altitude.

The high altitude pump, on the other hand, pushes slightly less fuel per stroke, but with the same frequency of strokes.

So if you live at lower elevations and go up high only on occasion, you can maximize heat at all elevations with the altitude sensor.

If you spend the majority of your time at higher elevations, and are OK with a little less heat if you happen to drive to a low elevation, you can install the cheaper high altitude pump and not have to buy the sensing kit.

(Because, as was said, heat output using the high altitude pump at lower elevations is somewhat less than the regular pump at lower elevations due to slightly less fuel being delivered.)

Also, in my limited experience, the heater will run at higher altitudes with no compensation. But you risk sooting it up if you do it too much because it is running a little rich. At, say, mid elevations (~5,000-7,000ish feet) I didn't notice any issues. At closer to 9,500 feet, it struggled to fire up initially (ran through two or three startup cycles before it finally lit up) and it smoked ever so slightly even after it was going.

I live in Kansas at around 1,100 feet, and don't have any compensation for elevation. I just run it on full blast for a while after the trips I've taken to the mountains, and have not had any issues with this practice. Your mileage may vary.
_________________
Dave Cook

President, Wild Westerner Club

1978 Champagne Edition Westy, repowered to '97 Jetta TDI
1973 Wild Westerner
My Thing

[owokie]

The fuel pump is the same for the B4/D2/D4

https://esparparts.com/fuel-metering-pump-p-25159.html

You'd have less risk than a diesel heater not using anything for elevation adjustment, the gasoline units do not tend to coke up as quickly as diesel when run rich. But like you mentioned, you're already dropping serious bank.

Either way you go, if the overnight temp is marginal for the B4 on low, you can simply intentionally drop your efficiency by cracking a window to prevent it from idling down.

[Steve M.]

[owokie]

https://www.heatso.com/espar-eberspacher-airtronic-b4l-m2-petrol-12v-4kw-heater-kit/

Heatso is usually the cheapest for full kits, in this case by a long shot from the link just mentioned.

[Steve M.]

[BCgee]

A quick update from MT on this project.

First, if you buy the "complete" Espar B4 kit off the eBay seller from Russia know that the kit is 99% complete. The notable piece missing from my kit is the floor base plate, which may or may not be a fluke. In any case I used a scrap piece of aluminum plate, traced the outlet holes and dimensions, and drilled accordingly. You might be able to get away with installing sans baseplate, but I do enough dirt and fire road driving that I didn't want to take chances with vibrations and random stuff shaking loose under the kid seat.

Because I'm installing the B4 under the bench seat in a Weekender interior, but keeping the stock rear heater, I needed to order additional parts from Heatso to accommodate the tight fit. Specifically a 90deg elbow for the intake, a 90deg outlet, one additional outlet, and additional vent tubing. As previously mentioned I already bit the bullet and ordered the high altitude kit from Heatso, which is presently taking its sweet time getting to my front door.

All together the likely cost for this install will be around $1500 +/- Not ideal, but then again so too is a cold wife and kids. We did last winter with only a weak front heater and I swore all the heat upgrades would get done before November, so here we are.

Looks like I'm on firewood missions this weekend with the N Rockies experiencing an early cold snap, then sadly I'm out of state for the following week, meaning likely won't get back to this project til mid October.

Onward!
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1987 SVX Syncro Hightop

[erste]

[Steve M.]

How did your install go?
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This free advice is worth exactly what you paid for it.

There are seven days in a week. Someday is not one of them.

[BCgee]

It took far longer than expected, but I’m happy to report the B4 is up and running like a champ.

So, How Difficult is it to Install?

The million dollar question! The Espar B4 installation is not very difficult for a moderately skilled DIYer. 95% of the frustration comes from Espar’s technical manuals, and the way they sell their kits. The Airtronics heater install kit comes with a ton of miscellaneous parts to adapt the heater to many different installations. I ended up with a box of unused parts.

The other source of frustration is that the wiring harness supplied by Espar is used for many of their products (and various combinations of their products with a half dozen or so different controllers). There is little clarity in Espar’s instructions for those unfamiliar with reading technical wiring diagrams. You’ll end up with a bunch of unused wires depending on your choice of controller. The whole installation process could be made hours shorter with simplified instructions written for dense people like me.

At the most basic level the Espar installation consists of:

Mounting the heater to your van (drilling a few holes and bolting it to the floor)
Running the wiring harness to where your thermostat/controller will be mounted
Hooking up air intake and exhaust outside van
Hooking up the hot air duct inside van
Connecting your fuel line and pump wiring to the gas line
Hooking up your thermostat/controller
Connecting to power

Espar desperately needs a new technical writer.

As the saying goes pictures speak a thousand words, so here are a few shots of my install plus the all important wiring diagrams that proved invaluable.

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1987 SVX Syncro Hightop

[shagginwagon83]

Wait is that a 90 degree heat output adapter?!

Sweeeet install! Is that a custom made shield for your combustion air intake?

Thanks for the pics/post!
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Brandon
"Jo Ann" - '83.5 Westfalia EJ22e w/Peloquin
Instagram @joannthevan

[TopBud]

Great info thanks. Any reason you choose Espar over webasto? I live at 7000' and often sleep at higher altitudes. I have a tintop with an open floor plan, no cabinets. We live out of the dry box also, most cooking done outside. Was hoping to mount heater underneath the van on the drivers side for maximum space inside. I access under the rear bench from a panel I pull off, not a westy bed, so not tons of room under the seat. I have the rear stock heater that I will be keeping in there (best way to warm boots on the way to the hill. Thanks
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86 bostig SYNCRO
66 convertible Karmann Ghia