Torpedo heater works only when *******??

[tmaxx]

I have an older Remington 25 forced air kerosene heater (torpedo style). It initially lights up and starts heating and then around 1 minute later it shuts off. I took the cover off and cleaned the photocell and air filter. With the top cover off, the heater works fine. Then I put the top cover back on and fired it up and it shut off after about 15seconds. If I remove the top cover again and fire it up, it runs fine. So why does removing the top cover cause it to run fine? How do I fix this, any ideas?

 

[tmaxx]

I forgot to mention that occasionally I hear a "screeching" sound coming from somewhere in the heater. It isn't constant. Sometimes, it starts and then goes away. Not sure if this is another clue....

 

[41ratrod]

does it have a fan and the cover is hitting it.
have you clean the tubing .
its been a long time since I worked on one of these, just trying to remember what it could be.

 

[66ragtop]

I have the exact same issue. I posted just the other day. It was recomended to clean the rotor and blades in the air pump. I tried it but it didnt work on mine. I think i might try to increase the air pressure at the pump.