Pilot will not lite

check to make sure that the poilet lite flame is touching the tip or top of the thermocouple.
the pilot lite needs to heat up the thermocouple so that the thermocouple opens the gas to the main gas log. a cold thermocouple shuts off the gas to the main gas log or gas burner and a hot thermocouple opens the gas to the main burner.
the pilot lite flame must be touching the thermocouple to heat it up.
pilot lite orface needs to be clear to let the pilot flame gas through with enough pressure so that the little flame can reach & touch the thermocouple. Pilot lite gas feed tube must be clear to let gas through. Use compressed air or a fine sewing needle, or even carb cleaner to clear out orface hole and gas feed line to pilot lite.

important!! WARNING:
if you use carb cleaner,make sure all the carb cleaner is dry,soaked up with paper towell or kleanex tissue and blowed out with compressed air , because carb cleaner can burn just like gasoline; so any carb cleaner must be compleatly gone before you attempt to lite the pilot lite.

Thermostat flame sensor. Do you see a little rod next to the pilot? That is what tells the main gas valve that the pilot is lit and it is safe to give gas. Easy swap, and you can usually just pick up a generic one.

sound like pilot lite is not getting thermocouple hot.
check that pilot lite flame is extending out to and touching thermocouple. If not, clean out pilot lite orface and pilot lite gas feed pipe all the way back to the main gas valve if necessary.
If pilot lite flame is touching thermocouple, then replace thermocouple

dirty pilot tubing or weak pilot generator

Hello
Sounds like the thermocouple is going bad.The thermocouple is a thin tube that runs from the pilot lite to the gas valve.
What it does is it sences the heat from the pilot lite and keeps the gas valve open to allow the pilot to stay on.
This can be easily repaird by shutting off power and gas to your heater and removeing the thermocouple from the gas valve,then unclip or unscrew it from the pilot lite area.
Any plumbing supply store or home depot or lowes should have these.

Once you get a new one,install to gas valve and pilot lite area then turn on power and gas to heater and follow pilot lighting procedure,you may need to hold gas on for 60 seconds.

Here is a picture of the thermocouple so you know what to look for.


http://thermocatalytic.com/Thermocouple.JPG
http://homerepairgeek.com/wp-content/uploads/2010/12/furnace-thermocouple.jpg

make sure the thermocouple is positioned above pilot light this part needs to be heated up by the pilot light to keep gas going to the pilot light. if the thermocouple is positioned above pilot light and it doesn't stay light, replace thermocouple.

jandy in and out pipes are 2" schedule 80 cpcv and should beavailable at any plumbing supply house. buy on 16" nipple and cut in half.Thread into headers then pvc cement the unthreaded end to tie into pump/filter system

THIS HEATER DO NOT HAVE A PILOT YOU MUST HAVE A DIFFERENT MODEL. DO YOU GAS? TURN KNOB TO PILOT PRESS. LIGTH PILOT WAIT FOR 60 SEC AND RELEASE IF STAY ON TURN KNOB TO ON. IF TURN OFF PILOT MUST BE REPLACE

If the pilot flame is not strong enough, it will not tell the gas valve to open, or if the gas valve is not getting the signal to open, it won't. Check all wire connections at the thermostat and gas valve. Check ground wires. Clean the pilot light and flame rod.