Espar high altitude compensation

[LarryB]

I have a 2017 Sprinter Sportsmobile built in Fresno that has a Rixen's D5 heating system installed under one of the seats in the dinette/bed. It (supposedly) has the high altitude compensation unit installed but I can't for the life of me locate it on my build. I've seen photos of what it's supposed to look like online I think (unless there are different configurations or perhaps sometimes built into the espar unit itself). They are primarily just a square box with a label it.


On a call with Rixen's about a minor issue, Michael asked me if I knew where the high altitude unit was and specifically the fuse for it. I said I did not and other than telling me to look in the heater area (which I've done), he didn't really have any suggestions as to where it might be. So I am wondering if anyone here has a similar build and knows where their altitude compensator is and could point me more specifically as to where to look.



Thanks for any help. As you might be able to tell I'm not well versed in the Rixens heater's ins and outs.

[1der]

It will be connected to the harness that runs from the heater to the on/off/temp control panel. If you can see behind where the control panel is, it may be hiding in there.

[LarryB]

I wondered if I should look behind the control panel as it's not down under the seat. I'll check there tomorrow.

[LarryB]

I checked behind the control panel as best I could (it's a small opening with wiring that must have been put into place before the cabinet build was finished) and there didn't seem to be anything that might be the high altitude altimeter box. And it's not down in the heater system compartment, unless it looks different than I think it does. I'm beginning to wonder if they didn't actually install one in Fresno even though I asked for one.

[1der]

Bummer.

If you do come across it, it looks like this, about 3.5" x 2.5"

[LarryB]

Thanks. I'd seen photos of the units before so that's what I've been looking for. I suppose it could be laying down at the bottom of the cubbyhole the control panel etc. are mounted in but if so that's a crazy place to put it since it would require dismantling the entire upper cabinet in the van to get to it I think.



I'd be concerned that I might not have one except that I've been using the heater since 2018, including at elevations at or near 10,000' occasionally and have not had any issues with it. But if I do have one and it quits working properly, it sure would be nice to know where to access it!


I haven't noticed anything like that under the floor of the van near the Espar unit itself but that's because I read you must install them in a clean dry place so figured it would have to be inside the van somewhere.

[Fitz]

The unit in my 2016 Texas built Sprinter is located behind the wall panel that the control panel is mounted on. It is buried away and not accessible, but as I recall I determined it was there by locating the wires coming from it at the back of the control panel.

[LarryB]

Thanks Fitz. Maybe that's where mine is then. I couldn't see down inside that area well at all so it could be sitting at or near the bottom. I had read about splicing wires to install one so you're probably right about being able to tell if it was there by the wires.



Michael Rixen was suggesting that I check the fuse that associated with the altitude sensor but I couldn't locate it either. I suppose if the unit is behind that panel the fuse may well be too. I wonder if I pulled on the right wires behind the heater control panel I could bring up the altimeter box and access it. That would only work of course if it is not screwed down somewhere out of sight. I gently tugged on the wires on the back of the control panel but they didn't seem to pull easily and I didn't want to accidentally pull something loose.


Since the problem I was having with my heater disappeared on it's own, I don't need to pursue it now but it would be nice to know just in case for the future. It seems like a really poor idea on Sportsmobile's part to put system components where they are not easily accessible!

[Fitz]

I went through a learning curve on my Espar. If you are bored I suggest you read Post 525 on page 53 of my build thread, you might find some useful information there.
https://www.sportsmobileforum.com/fo...tml#post222229

[LarryB]

I will do that. Thanks for pointing out the specific post. You have a lot of them (all useful, thanks for that too), and searching for anything very specific on the forum seems difficult to do.