>heater and it was receiving no fuel.  Removed the fuel pump and it no 
>longer pulsates, just clicks once - therefore no fuel is being delivered to 
>the gas heater.

Remove the inlet hose and try to get out the small mesh filter if it's
there. Use a thin nail/WD-40 nozzle better, and poke the piston a few times.
It must be connected to the heater (without hoses) to tick tick merrily.
Can also tap it on a wood block, alternating ends. This should loosen it up,
worked for me. Thanks to Tom Johnson in Alaska for this info. Wonder why he
knows? :)
   Tim Smith