[MicMan]

Just ordered (backordered) a gasoline heater direct from Velit, but this could also apply to a portable unit or other brands. Haven't settled on a mounting location yet, but bought now due to worries over tariff driven increases.

Does fuel octane rating make any difference regarding soot buildup in these heaters, or with any other issues? What about top tier vs non-top tier?

Oh... found a working discount code worth $50 at Velit - NATE50

 

[gregoryx]

Was recently some banter about this. Maybe? Quite possible that seasonal fuel changes might affect it; but hard to imagine other quality issues (like octane) since these things will run on just about anything...

 

[MicMan]

Was recently some banter about this. Maybe? Quite possible that seasonal fuel changes might affect it; but hard to imagine other quality issues (like octane) since these things will run on just about anything...

Didn't see anything when using the "Search Community" box, I try to not litter the forum with redundant posts.

 

[gregoryx]

It's a valid question. But I think it's only come up a couple times - including within the last week or two? But there's no solid answers. These heaters are really, really simple: they're closer in function to a diesel two-stroke engine with no valves and no spark plugs. In the cheap CDH space, the controller makes ALL the difference for everything. IOW, if fuel IS an issue, it's just a tuning thing... not that we're able to tune them...

 

[65Brier]

It's documented that you can't just burn gasoline in one of the cheap diesel truck heaters. I suspect it's because the gasoline vaporizes too quickly when the heater starts to warm up.

As @gregoryx says, they're really simple beasts, but there is engineering in getting the burner volume, air flow through the burner right for the amount of fuel being injected, placement of the ignition source, etc. All this is optimized for a particular fuel viscosity and range of air-fuel ratio requirements.

That said, road vehicle fuel gasoline is all very close to the same viscosity and vapor pressure no matter what kind you get. I suspect nearly anything short of E85 will burn about the same in one of these.

 

[Blur Rider]

This thread talked about vapor pressure of different gasoline blends possibly having an effect.

https://www.fordtransitusaforum.com/posts/1364502/

 

[SBMark]

I had a riding lawn mower carb get gummed up using the normal gas with ethanol from any pump. After that mess, I now only run ethanol free gas in any mower, snow blower, weed whacker, etc. Any chance the ethanol could gum up the injectors in the heater?

 

[gregoryx]

I had a riding lawn mower carb get gummed up using the normal gas with ethanol from any pump. After that mess, I now only run ethanol free gas in any mower, snow blower, weed whacker, etc. Any chance the ethanol could gum up the injectors in the heater?

Gum up the WHAT?

No, seriously... there are no injectors. Or a carburetor. Or valves. Or much else. I'm not sure how best to describe how simple they are. I'd say they're closer to a jet-engine... but that doesn't sound simple (even though it is). The diagrams barely help because it sure SEEMS like there's something more going on.

There's a, "glow plug," which is commonly found in a diesel engine (with no, "spark plugs," there, either). Basically, once the combustion starts working it keeps going so long as there's fuel delivered. I think the, "combustion air blower," is the internal air-mover that keeps the combustion air moving through the chamber (more similar to a jet engine in that way - once it ignites it keeps burning so long as there's air-flow and fuel available). But this is just my understanding... there's an Aussie guy on YouTube who has a series of videos where he goes through every aspect of these things.

 

[SBMark]

I'm not sure how best to describe how simple they are.

Dang, now I want to take mine apart. I'm an ex Aerospace Engineer and while engines weren't my specialty, I did get an A in AeroE 410 - Propulsion..... in 1989. 😂

I guess there's got to be some way to control/restrict the fuel into the combustion chamber and I assumed that was some sort of nozzle that could get gummed up with ethanol. Maybe there's an Afterburner mode to cook all the gunk off? 🤷‍♂️. I know my Ariens lawn tractor didn't have one stock but....

 

[Blur Rider]

Not related to gas heaters, but in general, gasoline powered equipment that goes long periods of no usage fare poorly on ethanol containing fuel.

 

[SBMark]

Not related to gas heaters, but in general, gasoline powered equipment that goes long periods of no usage fare poorly on ethanol containing fuel.

This is the lesson I learned the hard way with a lawn tractor carb rebuild. And what also makes me wonder if this same problem could occur with these heaters if they sit all summer.

 

[gregoryx]

Dang, now I want to take mine apart. I'm an ex Aerospace Engineer and while engines weren't my specialty, I did get an A in AeroE 410 - Propulsion..... in 1989. 😂

I guess there's got to be some way to control/restrict the fuel into the combustion chamber and I assumed that was some sort of nozzle that could get gummed up with ethanol. Maybe there's an Afterburner mode to cook all the gunk off? 🤷‍♂️. I know my Ariens lawn tractor didn't have one stock but....

The fuel metering is done by the controller and the pump. The "pump" is sometimes called a metering device or something like that; it never delivers a steady stream of fuel - just little "bubbles" of fuel, basically. The, "tick-tick," noise people hear is the fuel pump metering the fuel.

All the coking that tends to occur with these things is typically solved by running them leaner. That's also the issue with altitude: they need to be leaned out at higher elevation or they will coke-out if they run at all. The newer controllers use altitude to lean the fuel supply.

FWIW, this metering thing is also why they end up with issues when using a varied-size pickup (factory aux line): it's not developing a head of fuel the way that a legit pump would do. The water pumps we use in our sinks, for example, just push a steady pressure / head of water then they're "metered" by the faucet. This setup is more like the faucet is always fully opened and the pump turns off and on constantly to regulate the total flow of water.

The design was first built (and patented, if I understood that Mick guy) over 100 years ago. It's a simple device.

 

[gregoryx]

This is the lesson I learned the hard way with a lawn tractor carb rebuild. And what also makes me wonder if this same problem could occur with these heaters if they sit all summer.

Always fire them up at least once a month and let them get HOT. I used that model on our Sprinter (diesel) as well as the Transit and (knock wood) got five years on the Sprinter heater before selling it and already five years on the Transit. I suspect that it helps that it will sometimes run non-stop for days when I'm enjoying a good winter storm.

 

[Dave01]

Velit fuel type is all programming in the same physical unit. My unit shipped as a diesel, did a download and now it's a gas unit. And the instructions say it should be fired up monthly in the summer to keep it cleaned out and operational. 15 minutes stick in my mind, but I'll double check that come spring / summer. Got the laser temp thingy out to see just how hot the heated air was, at the end of the 2' of 3" hose, I was getting between 129F to 132F. Only issue I've had is it going into an Error 01 twice. Both times I was fiddling with the temp settings up and down and shutting things down playing with it. Now, I just turn it all the way down to 40F during the day and don't actually shut it off. I did get the instructions to put it into boot mode to reflash the gasoline download, but will wait until I'm home at the end of the month. While on the road, if it's at least functional... DON'T MESS WITH IT !!!

 

[Blur Rider]

The fuel metering is done by the controller and the pump. The "pump" is sometimes called a metering device or something like that; it never delivers a steady stream of fuel - just little "bubbles" of fuel, basically. The, "tick-tick," noise people hear is the fuel pump metering the fuel.

All the coking that tends to occur with these things is typically solved by running them leaner. That's also the issue with altitude: they need to be leaned out at higher elevation or they will coke-out if they run at all. The newer controllers use altitude to lean the fuel supply.

FWIW, this metering thing is also why they end up with issues when using a varied-size pickup (factory aux line): it's not developing a head of fuel the way that a legit pump would do. The water pumps we use in our sinks, for example, just push a steady pressure / head of water then they're "metered" by the faucet. This setup is more like the faucet is always fully opened and the pump turns off and on constantly to regulate the total flow of water.

The design was first built (and patented, if I understood that Mick guy) over 100 years ago. It's a simple device.

Wouldn't there be some kind of nozzle or atomizer for the fuel at the combustion chamber? I get that the pump cycling meters the fuel, but surely it doesn't just drip out into the combustion airflow?

 

[rf17830]

The pump in a parking heater is called a dosing pump. It delivers drops of fuel to the combustion chamber. You can hear the solenoid in the pump click as it pumps drops of fuel through the fuel line.

 

[gregoryx]

Wouldn't there be some kind of nozzle or atomizer for the fuel at the combustion chamber? I get that the pump cycling meters the fuel, but surely it doesn't just drip out into the combustion airflow?

If I understand the diagram - can't recall anything from when we rebuilt a friend's unit - there's a fan of some sort internal? I'd guess that's as atomized as it gets?

 

[SBMark]

I’d think if it just drips into the combustion chamber, you’d run the risk of air getting into the fuel line. Air, fuel, and flame in a tight space? Seems like a bad idea in this case. I still think there has to be a nozzle or some restrictor that keeps the pressure inside the fuel line higher than the pressure in the combustion chamber.

 

[Blur Rider]

I have a few NOS Espar diesel heaters in the garage. Maybe if I get bored I will open one up and see what the fuel delivery is like.

 

[JustSomeGuy]

Gum up the WHAT?

No, seriously... there are no injectors. Or a carburetor. Or valves. Or much else. I'm not sure how best to describe how simple they are. I'd say they're closer to a jet-engine... but that doesn't sound simple (even though it is). The diagrams barely help because it sure SEEMS like there's something more going on.

There's a, "glow plug," which is commonly found in a diesel engine (with no, "spark plugs," there, either). Basically, once the combustion starts working it keeps going so long as there's fuel delivered. I think the, "combustion air blower," is the internal air-mover that keeps the combustion air moving through the chamber (more similar to a jet engine in that way - once it ignites it keeps burning so long as there's air-flow and fuel available). But this is just my understanding... there's an Aussie guy on YouTube who has a series of videos where he goes through every aspect of these things.

View attachment 231936

That looks more like a clothes drier than a Jet engine : D