Rapid preheater flame going out

  • Hello from Ireland,

    I am struggling with my newly acquired second hand Petromax HK 500 lamp(1year old approximately)

    The flame in the rapid preheater goes out.

    Also the pressure goes down quite quickly.

    I keep pumping to keep the pressure at 1.5 then the flame goes out before 90 seconds are up.

    I hope you can help,

    Kind regards,


  • Hello Fiona,

    probably the pressure is a little to high for the rapid, try to keep at 1.0.

    It is possible that to high pressure blows out the flame of the rapid.

    Otherwise, if dosn't work, try to needle all the 3 dies of the rapid.



  • Hello Steven

    Thank you.I will try again.

    I ordered a new rapid preheater from Petromax and a repair kit.

    There seems to be a leak from the fuel tank ..well some liquid leaking from the rapid preheater leaver.

    I also need some help when starting with a new mantle and lighting with spirits..it didn't go very well.

    Happy Christmas,

    Kind regards,


  • hi fiona,

    to see if the fount holds the pressure and doesn't leak air,

    empty the fount,

    close the valves.

    pump with air for ~0.5 bar.

    then remove pump piston, hood, glass and frame,

    push the fount under water in a bucket.

    observe if bubbles appear at vaporizer, rapid torch, pump valve, tank filler, etc.

    the rapid torch needs for operation 1-1.5 bar. And it uses a lot of air from fount. So you need pumping throughout rapid preheat. That's normal. It's less demanding, if you fill the tank only half way with kero.

    and yes , a storm proof lighter is helpful for repeated ignition of rapid preheater.

    all quite normal.

  • Fiona, when i was beginning to learn Anchor lamps and Petromaxes, i often had loss of pressure...this can lead to things like "glowing mixing tube", i noticed that the lead seals for the vapouriser(carburretor,generator) and the rapid burner are very sensitive to movement(loosening of either very slightly disturbs the seal and causes pressure loss), Now i regularly check to make sure they have not been disturbed! Also when i operate the control wheel, i do that with a very slight pressure towards the left(tighter vaporiser)....When i use the rapid i also check this.

    I saw on a recent thread on this forum someone mentioning a method for fitting these lead seals which i imagine would make them less sensitive to movement...i can describe what they said if you like....i also noticed that fitting a new lead washer on top of the old one, rather than replacing the old one, seems to hold the vapouriser more firmly ( this means adjusting the air gap under the mixing tube slightly too ).

    Now that you are learning these lamps...Bommel's instruction at the top of this page on the complete overhaul of a Petromax shall become good reading for you. Good Luck! RxR

  • Thank you RxR.

    I was trying my lamp today and removed and cleaned the lamp down to the fuel tank but couldn't remove the rapid preheater.

    I reassembled the lamp and tried it and later removed some fuel from the tank and retried it.

    Their is a leak and air coming from the rapid preheater and the pressure is falling.I will reread your thread and hopefully be able to fix it.

    Thank you


  • The rapid needs a verythin spanner to take off easily, although you can remove the rapid by taking off the body, then the jet if you don't have that.... the rapid needs gentleness when tightening, by quarter turns, waiting for a couple of seconds each increment for the lead to "flow"... If you take out first the remains of old lead washers with a pin , you can count the number of turns required without a washer, this allows you to work more ...confidently, RxR

  • Thank you RxR.

    I will get a spanner and what other tools do I need for my lamp please?

    I only disassembled the lamp down to the fuel tank but didn't remove the control knob,pump or rapid preheater or fuel tank knob.

    I think the washer must be worn with the sound and hiss and leak and bubbles from the rapid preheater and pressure loss after pumping and also the flame going out and the top of the lamp going on fire.

    Are these washers in the repair kit?

    Thank you very much,


  • Thank you bp4willi.

    I am trying to disassemble the lamp,then see if I can find what is wrong.

    Where does that part go?

    Hopefully I will get it working soon.

    Is there a video on YouTube in English on how to clean and disassemble the lamp or just Bommels description?

    Thank you


  • Hi Fiona,

    the part Willi showed in the link (thread No. 10) is the rapid nozzle seal with holder. It is mounted on top of the rapid lever which moves away from the rapid nozzle when you operate the rapid.

    This little, elastic rubber seal is indeed very often the source of leaking as the rubber piece is gettting harde rafter several years, loosing its sealing capability.

  • Hello Netzwerk

    Thank you.I ordered a new rapid preheater...this part is probably with this hopefully.

    I hope to get time soon to figure out the problem and not destroy another new mantle and blacken the top of the lamp...

    Thanks so much.

    Happy New Year,