Espar D2 High Altitude Pump

rollerbearing

Well-known member
Troll,

To get it running again you might try disconnecting the fuel line and let the fuel pump into a container. Then cycle the heater through several dry start cycles ( this may remove enough carbon from the screen for you to get you a re-light.) Then reconnect the fuel line and try again.

It is not just altitude that can starve your heater of air. Excess inlet and exhaust piping and the muffler can cause problems too. I would try completely removing those pipes/hoses and run the thing on full blast for a while. Then think about how you can shorten/improve all those flows. Even with the HAK those piping issues can cause problems. The HAK is open looped and only corrects for altitude not flow restrictions.
 

OrioN

2008 2500 170" EXT
Troll,

To get it running again you might try disconnecting the fuel line and let the fuel pump into a container. Then cycle the heater through several dry start cycles ( this may remove enough carbon from the screen for you to get you a re-light.) Then reconnect the fuel line and try again.

It is not just altitude that can starve your heater of air. Excess inlet and exhaust piping and the muffler can cause problems too. I would try completely removing those pipes/hoses and run the thing on full blast for a while. Then think about how you can shorten/improve all those flows. Even with the HAK those piping issues can cause problems. The HAK is open looped and only corrects for altitude not flow restrictions.
Notwithstanding he's using a stock pump setup at high altitude, I no longer idle my D4 on it's lower setting.

Being a full-timer and living in the PNW, I run the unit every day from late Nov through end March, and at a minimum once a day to wake up.

I replaced the blower and added a new screen prior to last winter. For the first time, I've not have had to an annual or mid winter screen change. The only time I see 'smoke' is during or after I 'flame-out' when I run out of fuel (occurred twice when tank was low and driving up a steep hill).

During the cold days, I start the unit and run it up to 22C and turn it off when it hits the low idle. Being insulated the residual heat can last a few hours or until late afternoon sunset, then I will fire it up until idle again. As the residual heat is dissolving, I layer up.

I sleep under down, and with wool socks and beenie.
 

rollerbearing

Well-known member
It was running with a blocked combustion inlet for a short while which makes the sooting far worse than just an altitude problem.
 

rollerbearing

Well-known member
Troll,

Be sure and reconnect your exhaust when you are done with the burnout - you want it moved safely away especially if you are sleeping. You can look at shortening it or removing the muffler when the opportunity presents.
 

TROLL

2007 Winnebago View 23H
Just took it apart, very simple unit and very easy to take apart now that I see how it goes together. I had already taken it out of the vehicle which was most of the work at this point.
On everyone’s advice here I got a 7mm tap and it worked well. It pulled a tiny bit of metal strand from the top edge but I do t think that will affect things unless the elders here say otherwise.
Inside here is what I found. Yikes.
Going to clean with brake parts cleaner and a brush, then a butane torch and finally compressed air. I will clean the screen and the small hole where the fuel enters. The hole didn’t look clogged but the screen sure is in that one spot. Sound like a decent plan?
 

Attachments

Midwestdrifter

Engineer In Residence
Sounds like a good plan. The screen doesn't need a solvent wash, just a torch. It will glow red, and eventually all the carbon will burn off.

Scrape the burner as best you can. If you have a propane/butane torch of decent size, you can direct it down the burner bore. It will heat the flame holder and screen to glowing. After 10-20 minutes you should have a fairly clean burner.

That light coking may come off with a solvent wash. If there is shiny black rock-like deposits deep in the burner, the flame approach is the best method I think.
 

TROLL

2007 Winnebago View 23H
Yeah sorry for hikacking, not my intentions. Trying to document so people can at least see what’s involved and honestly it’s a lot quicker and easier than I expected (along with the great help here like the tip on the 7mm tap).
Here’s the screen during and after. You could see the deposit fade away within the yellow glow.
 

Attachments

Midwestdrifter

Engineer In Residence
Use a bright light from the back, and look DEEEEEP into the burner. The area around the glow pin bore is surrounded by a screen (under the welded circumference). If that area looks pretty clean, you are good to go. If the screen is badly coked, the unit will usually light off fine, but the flame will be unstable, and may blow out at high power. As opposed to the glow pin screen which will prevent starting, but won't affect running unless totally plugged.
 

sprint2freedom

2008 NCV3 170ext
This is not relevant to the full disassembly route shown above, but just for show-and-tell purposes here's my DIY socket for removing the glow pin:

glowtool.jpg

I started with a $5 auto parts store 12mm socket, drilled a starter hole with a drill press (beginning with a 1/8" bit and working my way up), then used a dremel tool with diamond cutoff wheel to make two parallel straight cuts between the open end of the socket and the newly drilled hole. After cleaning up the edges a little with a file it came out looking like it shoulda cost 30 bucks! :tongue:
 

TROLL

2007 Winnebago View 23H
Nice work sprint2freedom! I think I will follow your lead and start with drilling the end. did you go up to 1/4" or what size did you finish with?

To follow up on my project, I put it all back together and fired it up, everything seems great so far. I have a bit of tidying up to do but its very cold tonight in Denver so I'll leave that for mid day tomorrow. The heater is currently bringing the inside temp from 28 degrees up to 75 degrees and all seems well so far (as long as none of my plumbing cracked when it was frozen for the past 24h). Again, really appreciate the help you guys are willing to give here and I always try to pay it forward when I can.

I'll be installing the HAK as soon as it arrives and hope that will improve my situation. I bought this heater to maintain a comfortable temp so it will spend its fair share of time on low, but I will be more aware to make sure and run it on high more regularly as well. I should also be able to shorten my intake tube by about 30% from the original length provided with the kit. The exhaust/muffler will have to remain the same length as was provided with the kit in order to exit out the side of the vehicle. Hoping to head from Denver (5,000 ft) to Mammoth Mountain (9,000 ft.) in about a week so hopefully the HAK gets here ASAP.
 

sprint2freedom

2008 NCV3 170ext
Nice work sprint2freedom! I think I will follow your lead and start with drilling the end. did you go up to 1/4" or what size did you finish with?
Thanks! I just checked the slot width and it's right around 11/64" which is pretty much 3/16". The width and depth of the slot I made turned out to be about perfect- plenty of room for the glow pin wires without compromising the socket.
 

YOLOMOG

2016 170" 4x4
If anyone is still wondering about the high altitude pump, I got that with a D4 back in 2016 for my 170" 4x4 since I was planning on using it in the Rockies above 9,000 feet. Because I had the D4, I didn't need the extra BTUs of the regular pump at sea level where the temperature is typically warmer.

The high altitude pump and D4 worked great at Taos and Telluride when I ski camping there and the temperature was -19C (-2F). The kit came with a regular pump, and I live in Seattle so if the HA pump fails I can always swap in the regular pump. I found this post because I'm about to do my first service on the D4 after 4 winters. I plan to burn off the soot with Kerosene (1 gallon low-sulfur version from Home Depot), then remove the atomizer screen to see how much soot is left on the atomizer screen. Because of Covid-19, I won't be skiing much this winter and am hoping that running with Kerosene and replacing the atomizer screen will be enough for this winter. I tried removing the fuel line that goes to the high altitude fuel pump so I could connect it to the Kerosene, but the fuel hose is sticking to the inlet valve. Hopefully I can unscrew the bolt that holds the fuel filter onto the pump and screw on the version from the regular pump to run Kerosene through the D4 so I don't have to put more force on the fuel line to get it unstuck.

In retrospect, a D2 would have been enough heat since the D4 tends to heat the van up enough, turn off, and then not turn back on until the temperature is a few degrees below the set point. The only times it has run all night has been when it was really cold (-19C or -2F) like at Taos. I'm definitely glad I got the high altitude pump vs the HA sensor kit since I can use the regular pump (from the D4 kit) for parts or emergency replacement, and because Murphy's law means there are more ways that the HA kit could get into a fault situation than simply using a low-output HA pump.
 

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