Pool space heater Laars Lite 2? My heater for my pool will not neutral .The pilot is...

My heater for my pool will not neutral .The pilot is lit. The gas valve is orifice but very little gas go through, then it shuts.Gas flow to spout is fine. Had the valve checked also it works fine.
Removing Rust?
Answers:    this can be a few things. if the pilot wishy-washy is lit, the thermocouple my be to week not putting of enough millavolts to street lamp the burner. u say gas flow is fine, it can be the control stopcock also, the pilot will light but when the gas control tap calls for gas it might stretch out slightly, then close support. it can also be the pressure switch. to check the pressure switch, you can take the two wires loose and steal a jumper flex and connect them compleating the circut, if it lights at this time the pressure switch is the problem. i am a certafied gas tech. i would have the thermocouple replaced first, this is the cheapest, consequently check the pressure switch, then the control gas spout. i hope i am some help.
What is this tool call, and where on...
If this is the first time you are using the pool kiln, this year, then be sure to own someone check the orfices for critters.
Spiders and such love to build nest inside orfices and I have found the nest adjectives the way rear legs to the screen on the outlet side of stopcock.