Parking heaters at altitude

jaross

Member
I have a Webasto Airtop 2000st gasoline and I am at my whits end! It has been a nightmare. Multiple failures due to carbon buildup, and I've had a shop lean it out for altitude. Last night it failed again. I was at my folks place around 7200ft. I also regularly expect to operate a heater at 9000ft. It is utterly ridiculous that these heaters cannot be designed for that to be okay, but apparently thats the case. I am thinking of trying an Espar B4L M2 (gasoline, 4kbtu). I am also considering doing a diesel heater, because I hear they maybe less problematic. Any advice?
 

Joe917

Explorer
Our Webasto (ThermoTopC diesel) runs flawlessly up to 4200m (14000') above that it can be finicky, Over 5000m (16000 ft)I found blocking the exhaust with my thumb on start up seemed to help, back pressure i guess. Could be your unit is not adjusted correctly or the gasoline units are more sensitive. There is a way to adjust the heater with a rheostat, try google.
 
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My only experience with diesel heaters is with Walas heater/stove units. Expensive and if not run properly, problematic. Have used ours at 4000+ feet, with no issues.
 

bglenden

Member
My understanding is that some of the cheap Chinese diesel heaters can have their altitude adjusted through their LCD control panel (I think it adjusts the fuel pump cycle, presumably altering the fuel/air mixture).
 

jaross

Member
Our Webasto (ThermoTopC diesel) runs flawlessly up to 4200m (14000') above that it can be finicky, Over 5000m (16000 ft)I found blocking the exhaust with my thumb on start up seemed to help, back pressure i guess. Could be your unit is not adjusted correctly or the gasoline units are more sensitive. There is a way to adjust the heater with a rheostat, try google.

My unit has been fully leaned out by a certified tech. My whole install was just recently looked over by a certified tech, and they told me it looked fine :mad:
 

luthj

Engineer In Residence
There are also some Asian clone fuel pump with different stroke volumes. Using one of these reduces the fuel burn (and heat output) by about 15%. Which allows operation at higher altitudes without issue. If you have very short intake/exhaust tubes with minimal bends, it will get you another 2-3kft altitude before the coking starts.
 

burleyman

Active member
Apologies for the drift away from the OP's gas burner, which I wished I had after my first diesel sooting. Oh well.

I have a 2kw Airtronics Chinese diesel clone in an Econoline because of the condensation issue. When looking at offerings, dimensions are important to get the small 2KW version. Close attention can also get you one with adjustable, programmable fuel pulse settings.

Past experience for decades with diesel/kerosene boilers and heaters and the STANK, nastiness, sooting, and continuing maintenance made me put it off for some time. My initial experience with the Chinese clone verified that disgust. Sooting after hours of use.

After the joys of cleaning a sooted burner and listening to the exhaust, a subtle change in noise indicated beginning sooting. A blast of air into the intake while running would blow "soot boogers" out the exhaust and delay cleaning.

Finally, installing a 16ml fuel pulse pump instead of the supplied 22ml pump, and burning K1 kerosene has resulted in happiness up to 6000 ft. No problem with pump failure due to kerosene yet.


9 amps for the glow plug on startup, .8 amps to run the single motor that supplies both heated air and combustion air.

The addition of a section of flexible duct for my wife's use as a hair blow dryer has increased my maintenance pressures.

I would prefer a miniature propane forced air variety with similar power requirements.
 

luthj

Engineer In Residence
The espar install manual would be my bible when installing one of the chinese clones. Strictly following the tubing diameter, length, and bend requirements for the intake/exhaust plumbing. I have seen a number of installs of both webasto/espar air heaters which coked up very quickly do to excessive intake/exhaust restriction, or mounting at a bad angle.
 

Victorian

Approved Vendor : Total Composites
Our regular Planar diesel heater WITHOUT altitude compensation worked just fine at 10.000ft . We are now offering the same heater with an automated altitude adjustment that promises 8500ft from the manufacturer. I'm very confident that you can easily operate it well above 10.000ft. If you need more altitude, you can always run it on kerosene to avoid soot built up. We have sold several hundred of the planar 2D heaters and never had anyone calling us for spare parts or operating issues! Btw, we are currently running a promo on our website. https://totalcomposites.com/product/diesel-air-heater-planar-2d-12-high-altitude-with-accessories/
 

jaross

Member
Our regular Planar diesel heater WITHOUT altitude compensation worked just fine at 10.000ft . We are now offering the same heater with an automated altitude adjustment that promises 8500ft from the manufacturer. I'm very confident that you can easily operate it well above 10.000ft. If you need more altitude, you can always run it on kerosene to avoid soot built up. We have sold several hundred of the planar 2D heaters and never had anyone calling us for spare parts or operating issues! Btw, we are currently running a promo on our website. https://totalcomposites.com/product/diesel-air-heater-planar-2d-12-high-altitude-with-accessories/

Do you know if it is the same mounting footprint as a Webasto 2000 or Espar D2/D4?
 

jaross

Member
There are also some Asian clone fuel pump with different stroke volumes. Using one of these reduces the fuel burn (and heat output) by about 15%. Which allows operation at higher altitudes without issue. If you have very short intake/exhaust tubes with minimal bends, it will get you another 2-3kft altitude before the coking starts.

Anyone know what the Webasto 2000ST petrol pump ml is? What ml should I downsize to?
 

luthj

Engineer In Residence
I am pretty certain the webasto workshop manual has a fuel pump volume test. This can be used to see how many ml per 1000 pulses it produces.
 

dreadlocks

Well-known member
Espar has an electronic altitude kit that uses an air pressure sensor to adjust fuel dynamically with their heaters.. wonder if they can be used with other heaters.
 

luthj

Engineer In Residence
Espar has an electronic altitude kit that uses an air pressure sensor to adjust fuel dynamically with their heaters.. wonder if they can be used with other heaters.

There are two altitude kits. One is just a low flow pump. The other is a sensor (really a way to get more $$ from buyers). The sensor sends data over a 1 wire data bus, and is espar specific. These kits have been discontinued, becuase the newest espar heaters have a built in pressure sensor on the ECU (a 10 cent part!!).
 
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