Torpedo/salamander heater problem

[fishersguy]

Protemp 125 kerosene fired heater. Only starts with cover open, then I can close it , runs fine. New noozle, air pump filters ,pump psi 5lbs, pump vanes and clearance ok, fuel filter ok, hoses tight, photocell jumped, Any other suggestions please, thanks.

 

[JohnnyG]

Didn't we see this same problem a year or two ago. It sounds very familiar.

 

[kschachn]

Didn't we see this same problem a year or two ago. It sounds very familiar.

Perhaps here. IDK how much help it was though:

H

Thread 'Trouble with DeWalt torpedo heater'

Jan 26, 2025

I have a DeWalt DXH190HD torpedo heater that I can not get to burn correctly. It burns fine with the cover off, but when I put the cover back on, it “surges”. The flame goes out and back on. If I restrict the air on the back of the heater, it runs slightly better. My air pressure is close to correct. (My gauge is bouncy). I’m thinking that I must not be getting enough fuel or too much air. I can’t turn down the air. The fuel filter is clean, I have replaced all the air and fuel lines, and cleaned the nozzle. The pump is clean and the veins move freely as they should. I have two other...

• Hawk Fan
• Replies: 6
• Forum: General and Off Topic

 

[JohnnyG]

Are those scrape marks on the top cover? If so, the fan blades are hitting the cover and messing up the air flow. Might be a sensor involved in that scenario.

Nevermind, I see that you checked the fan blade clearance.

 

[Gyro Gearloose]

Just a comment that lean mixtures are difficult to ignite although they will burn once started. Superficially it would appear the open cover allows much of the fan air to escape without having to go through the burner zone. Does the heater have a primer button or start setting that provides a bump in fuel to get it started?

 

[ripcord]

Just a comment that lean mixtures are difficult to ignite although they will burn once started. Superficially it would appear the open cover allows much of the fan air to escape without having to go through the burner zone. Does the heater have a primer button or start setting that provides a bump in fuel to get it started?

This seems like a very reasonable answer to me. Possibly slightly obstructed fuel metering somewhere?

 

[fishersguy]

Just a comment that lean mixtures are difficult to ignite although they will burn once started. Superficially it would appear the open cover allows much of the fan air to escape without having to go through the burner zone. Does the heater have a primer button or start setting that provides a bump in fuel to get it started?

No primer button or start setting. Doubt it's lean mixture as I can smell kerosene and if I try enough times I can see kerosene in the burn chamber.... It stays running once started and stays running, no surging, burns fine..

 

[fishersguy]

This seems like a very reasonable answer to me. Possibly slightly obstructed fuel metering somewhere?

When I replaced the nozzle I removed the hoses, and blew out the burner head..

 

[fishersguy]

Are those scrape marks on the top cover? If so, the fan blades are hitting the cover and messing up the air flow. Might be a sensor involved in that scenario.

Nevermind, I see that you checked the fan blade clearance.

The air pump rotor clearance and rotor vanes being free are what I checked. Yes the cover does hit the fan blades, if the cover is not properly positioned..

 

[ripcord]

When I replaced the nozzle I removed the hoses, and blew out the burner head..

There must be a metering jet somewhere in the system. It could be dirty. Perhaps a partially clogged fuel filter or pickup screen in the tank?

 

[fishersguy]

There must be a metering jet somewhere in the system. It could be dirty. Perhaps a partially clogged fuel filter or pickup screen in the tank?

Removed pickup tube its clear and screen looked fine but cleaned it anyways. I would assume the spray noozle I replaced is the metering jet..

 

[mk378]

If you start with the cover closed, does it light and go out, or never light at all?

If it never lights at all, the ignition electrodes may be in the wrong place.

 

[fishersguy]

If you start with the cover closed, does it light and go out, or never light at all?

If it never lights at all, the ignition electrodes may be in the wrong place.

It never lights with cover closed. The spark electrodes are not adjustable . Fixed 2 prong spark electro

 

[ripcord]

Will it light manually with lighter with the cover closed? Protecting yourself from the flame, obviously.

 

[fishersguy]

Will it light manually with lighter with the cover closed? Protecting yourself from the flame, obviously.

Didn't try that. However I can hear the spark plug...
..

 

[mk378]

Can you move the nozzle back so the sparks are more in front of the nozzle? I'm thinking that with the cover closed there would be more airflow which blows the oil spray forward.

 

[fishersguy]

Can you move the nozzle back so the sparks are more in front of the nozzle? I'm thinking that with the cover closed there would be more airflow which blows the oil spray forward.

No.