o/t Diesel Space heater (2024)

I have a small diesel powered space heater for my workshop which until recently ran well. What happens now is that it fires up and runs for a few seconds then stops, it used to run longer between stops but its now down to a few seconds. I have checked the fuel and it seems to be clear of blockages. Is there some form of thermal cut out that can go wrong. Any ideas welcome.
Thanks
Bill

Have you checked the spark plug?

Many of the space heaters I have seen have a little air injector pump, to draw the fuel out of the tank. They have a foam air filter that gets plugged up with whatever's flying around the shop (overspray, etc.) Open it up and see what's in there. Many heaters also have a flame-sensing eye to shut it down if something abnormal happens. If this eye gets a layer of dirt on it, it can't see the flame and thinks something is wrong, and shuts down.

There is also a screen in the fuel pickup pipe that plugs.

Where on the machine am I likely to find the magic eye? There appears to be planty of fuel but as you say something is shutting it down.
Thanks
Bill

Most torpedo type heaters have online trouble shooting guides ,just google the msnufacturer or use a generic "Remington heater" will get you there. They all work pretty much the same . Fuel pickup tube goes to nozzle , air pump to nozzle , fuel is sprayed by siphon effect . Flame sensor eye needs to see bright flame to keep running , it's a CAD cell the should be mounted close to nozzle , you will need to tank top cover off heater to see it . They get dirty or go bad .

I had a heater doing the same thing. I cleaned the eye, replaced one of the fuel lines that had a crack, checked the fuel screen and it still didn't work. Finally I drained the old fuel and adjusted the pressure. Then it worked. My heater is supposed to show around 4.5 lbs pressure but it runs best at 2 lbs.

Plenty of fuel you say? If it shuts down before it lights, electronics are probably okay. If it lights then shuts down, then the eye needs to be serviced. It should be located in the combustion chamber near the nozzle. Plenty of fuel and no fire? Water in fuel, or low fuel delivery. You might see a lot of fuel coming out, but it might not be quite enough. There must be a proper mixture in the combustion chamber or it will never burn (too lean). But before you overhaul the thing, you have to make sure there's no water in the tank. Dump all the fuel out, clean out the tank real good.