Why wont the unit light? pilot is working fine

Hi John,
If your problem has not been fixed or a solution not found yet then you may consider this. Flash units are built with many tiny parts; thus, when a single component malfunction, it will render the whole unit useless. You mentioned the pilot light is not working - that indicates that power is not flowing through the unit.
Check the filament of the unit - if you notice some brownish stain on either end of the tube, it indicates the filament has burned out. Changing the type of batteries won't make any difference.
the only option you have now is to service the flash unit

Thermocouple maybe defective

if the pilot lights when held but wont stay lit, the thermocouple is shot, local hardware stores sell universal thermocouples. self explanatory to replace. if even when pressing the button the pilot doesn't light there is a blockage in the gas line or control valve. that needs a pro to fix.

Any kind of gas needs oxygen to maintain combustion.

never heard of having a pilot light as well an ignitor, the two don't go together. If your have a pilot light that is on the unit is getting gas. If there is pilot light there is usually a knob to switch between pilot light, off, and active on. maybe set to pilot light only.

I worked on plenty of them. Usally it is the termocoupling needs replace. It's easy to replace and you can pick that up at Fagers, Michells, or a heating and plumbing store.

Change the thermocouple.

If your Raypack (mine is a 2100 but most have the same electronic ignition pilot) lights and runs for about 2-5 minutes an then shuts off, you need to clean the pilot sensor. The pilot sensor tells the unit the Burners are running. If the pilot sensor becomes corroded, carbon, etc. the unit will light but will shut off after a few minutes as it thinks the unit is not operating properly. The unit will try to re light, but fail, and then PLT will show on the main programming screen. To fix the probelm, shut off the unit power. Remove the pilot assembly which is located at the bottom right of the unit. There is one screw holding the pilot assembly in place. Gently remove the pilot assembly. There is a fork like probe sensor (not the one with ignition and gas feed) that needs to be cleaned. Take some rough sand paper and clean it thoroughly. Re insert pilot assembly and fire the unit. If this fails, clean the sensor again. Problem solved!

there is a small adjustment screw on the gas valve,turn it clockwise to increase pilot,if that does not work the vent cap on the gas regulator on the back of the unit could be stopped up,remove that cap ,clean out or replace unit can operate without it just fine.If you increase the pilot and it still wont stay lit replace the thermocouple

sounds like when burner kicks in it is diverting gas away from pilot. you have either too low pilot heighth or more likely an obstruction in pilot assembly