[83Grumman]

The Lowes small worm gear clamps solved that issue of having air in the fuel line and dripping fuel during startup. After clamping I tapped and flicked the bubbles out of the line going up to the heater. It's working great now.

Those are not the best clamps for the hose. They might work for now but you should use the correct size fuel injection line clamps.

 

[MaggieMarty]

Those are not the best clamps for the hose. They might work for now but you should use the correct size fuel injection line clamps.

Something like this?
Getting my Velit today!

Nitro 4x4 1/4in Hose Clamp 10 Pack

Shop for Nitro 4x4 1/4in Hose Clamp 10 Pack with confidence at AutoZone.com. Parts are just part of what we do. Get yours online today and pick up in store.

www.autozone.com

 

[Pierre O]

Something like this?
Getting my Velit today!

Nitro 4x4 1/4in Hose Clamp 10 Pack

Shop for Nitro 4x4 1/4in Hose Clamp 10 Pack with confidence at AutoZone.com. Parts are just part of what we do. Get yours online today and pick up in store.

www.autozone.com

Same type; as @83Grumman mentionned these are sometimes called "fuel injection clamps"; but maybe these are too small. Often 10 mm ones are used such as these: Webasto Fuel Line Clamp 10mm 5 pack 5012000MP5. Similar ones should be in your velit kit.

 

[teethandnails]

Ok! I tightened the 2 clamps at the sending unit, and then the two clamps at the inlet for the fuel pump. I turned on the heater, and once the fuel pump kicked on there was no space or bubbles in the line, just solid fuel on the inlet and outlet end of the fuel line and then the heater fired up without issue. I’ll keep an eye on it though. Thank you for the help folks.

 

[83Grumman]

Something like this?
Getting my Velit today!

Nitro 4x4 1/4in Hose Clamp 10 Pack

Shop for Nitro 4x4 1/4in Hose Clamp 10 Pack with confidence at AutoZone.com. Parts are just part of what we do. Get yours online today and pick up in store.

www.autozone.com

Those are probably too big. Their range is from just over 1/2" to 7/16", they are 1/4" wide.

The ones Pierre linked are probably the correct size. Please put a drop of oil on the hose where the clamp will contact, it helps. This is a low, low pressure/vacuum application, they don't need to be overtightened.

I also oil the threads/screws on all the clamps I use, it allows the torque to go where it is supposed to.

A good oil can with a flexible spout makes life easier. I use Goldenrods, 16 oz. Oil everything mechanical that can use it.

 

[83Grumman]

Ok! I tightened the 2 clamps at the sending unit, and then the two clamps at the inlet for the fuel pump. I turned on the heater, and once the fuel pump kicked on there was no space or bubbles in the line, just solid fuel on the inlet and outlet end of the fuel line and then the heater fired up without issue. I’ll keep an eye on it though. Thank you for the help folks.

I don't see any evidence of oil under those clamps.

 

[SteveSS]

Fuel injector hose clamps come in small sizes and work well too.

 

[Pierre O]

This is a low, low pressure/vacuum application, they don't need to be overtightened.

Eberspacher (and Webasto also if I recall) specify 1 to 2 Nm (9 to 18 in-lb). It's not a huge torque. It is important also that the clamp is not bent, otherwise it will not clamp evenly. Normally if you have the correct torque the "ears" should be close to touching one another but the clamp should not distort the rubber hose.

 

[83Grumman]

the "ears" should be close to touching one another but the clamp should not distort the rubber hose.

If you don't distort, crimp, crush or squeeze the hose to compress the hose material it won't seal. The clamp needs to be tightened until it can't be rotated or slid on the tube and then a little bit more.

 

[teethandnails]

Took 2 times to start at 10,700ft again. It’s weird, at my house at 5280ft it starts with zero issue first time and runs like a champ, but at 10,700ft at the ski hill if I prime the pump, it starts first time; but if I don’t I get error 01 or 07 and then I prime the pump and then it starts and runs fine all day while I’m skiing. There is no air bubbles or gap in the fuel in the lines, checked before cranking it up this morning. Maybe I should use the stand pipe instead of the quick disconnect? Also, Happy Holidays folks and thank you for all the help

 

[MsNomer]

I'd guess a very small leak that causes a very small bubble you don’t see but is bigger at higher altitude. Problem is that when the bubble is bigger is exactly when you don’t want to be under there looking for it. We had something like that til MrNomer tightened fittings that seemed like they didn’t need tightening. High altitude is very unforgiving.

 

[scribblersix]

From the manual:
"The performance may be compromised when using the auxiliary fuel port above 6000ft."
This may be an understatement.

Thought I would try it @8000ft w/ aux fuel port since its not terribly far off from the recommended max and is the highest I will need to run it. Figured I could always install the standpipe if needed. It fired up great the first few times. Did notice some darker exhaust smoke.

Then would not always fire up, or would flame-out after a few hours.
Then would not fire up at all, or flame out within a minute, even at lower elevations.

Decided to take apart as it was just a paperweight at this point.
Exhaust was nearly completely clogged. the inside of the heat exchanger was caked with 1/2" of soot as well.

Is this the effect of trying to run at altitude without the standpipe? Bricking the unit?
This doesn't feel salvageable but I am cleaning the thing out and reinstalling.

 

[MsNomer]

I'm more interested in that muffler. Did it come with the kit?

 

[teethandnails]

I'm more interested in that muffler. Did it come with the kit?

Mine came with a muffler. I didn’t use it as it’s pretty quiet without it.

 

[83Grumman]

From the manual:
"The performance may be compromised when using the auxiliary fuel port above 6000ft."
This may be an understatement.

Which heater? The Velit?

 

[PJ-PJ]

Which heater? The Velit?

VELIT 4000P User Manual page 11

"3.3 Installation of fuel supply system

The fuel supply system of the heater is shown in the following figure. NOTICE We strongly recommend installing the standpipe instead of using the auxiliary fuel port for better reliability and performance. The performance may be compromised by using the auxiliary fuel port above 6000ft ASL. Any standpipe with an internal diameter of 2-2.5mm will work."

 

[MaggieMarty]

Jurs

I'm more interested in that muffler. Did it come with the kit?

Just received my Velit and it came with a muffler.

 

[scribblersix]

Velit 4000

I'm more interested in that muffler. Did it come with the kit?

Muffler did come with the kit.
Also they removed the note in the instructions about the supplied standpipe only being compatible with metal fuel tanks. So I ordered the fuel tank sending unit removal tool in case I am able continue with this project.

Would have though gas would have fewer ignition problems vs diesel (which i used to have) since its more flammable and volatile

 

[RV8R]

Velit 4000

Muffler did come with the kit.
Also they removed the note in the instructions about the supplied standpipe only being compatible with metal fuel tanks. So I ordered the fuel tank sending unit removal tool in case I am able continue with this project.

Would have though gas would have fewer ignition problems vs diesel (which i used to have) since its more flammable and volatile

Hi @scribblersix

Sorry your unit sooted up, but really appreciate the report. Your report will help others, as we are all kinda “beta testers” here for others that will consider a purchase & installation.

In testing, dialling out the variables are important. From my limited knowledge of The Velit there seems to be the following variables;

Muffler
Standpipe
Altitude (which should be recorded with pressure & temperature - in aviation that is called Density Altitude)

I would hope you are contacting Velit & receiving their take on it. Also hope you continue to post about your coking up issue & remedies. This can be very helpful to others attempting to have a problem free installation.

 

[larry barello]

"The performance may be compromised when using the auxiliary fuel port above 6000ft."
This may be an understatement.

I doubt the standpipe significantly contributes to your issue. From the symptoms (severe carbon build up) there appears to be something defective in your unit causing a gross excess of fuel being burned.

Based on first principles, a larger diameter standpipe shouldn't have any effect on the fuel supply. Hydrostatic head is independent of the pickup diameter. There may be other factors involved, but nothing that would grossly increase the supply. I would like to hear from Velit what, exactly, is the issue and problems with the built-in standpipe. Just saying "performance may be compromised " doesn't work for me.

Wrong pump? Wrong nozzle? Wrong calibration (e.g. set for diesel)? Clogged air intake? Bad altimeter in the thermostat? It's likely going to be hard to figure out the root cause, but if/when you do, let us know!

For reference: I use regular fuel line from the tap to my pump, then the nylon pressure line to my Webasto, which I 'leaned out' a bit. After four years and plenty of run time at altitude (6-8k'), it has a bit of soot in the exhaust and still runs fine. Sample of one, YMMV.