I just replaced the "pilot generator"...now the pilot light stays on, but the hearer will not light... Any recommended starting place for trouble shooting would be appreciated.

Check the new thermopile with a millivolt meter and make sure it has the correct output not connected to the gas valve.If it does,then the gas valve is defective.Make sure to test ONLY the thermopile.If it does not generate enough millivolts the gas valve will not open.If the piliot is dirty it will not generate enough heat for the thermopile.Make sure you have a good,strong,blue flame at the pilot.You said the piliot will not stay lit?If not then start by blowing air back through the piliot where the flame comes out with compressed air.hopefully that will clean it well enough.If not you may have to take the pilot tubing loose from the valve and use compressed air to clean it.Make sure when you reconnect the tubing to the valve USE FINGERS ONLY to start tyubing or you may crossthread the tubing....and thats NOT a good thing.Good Luck.

You have a "pilot generator" that sits in the flame of the pilot light. This generates a low voltage output from the flame of the pilot light. This voltage goes to the gas valve and tells the valve that the pilot is lit and to keep the pilot gas line open.
In almost all cases replacing the pilot generator will resolve the issue . They run about $60-$75.
Other causes may be the gas valve itself or a short in the safety loop, in either case should be looked at by a pool tech.

This symptom indicates something wrong with the millivolt system. Start by checking the wires from the thermopile to the gas valve, insuring they are all tight and in place. Check the hi limit thermostat, if you have an ohm meter it should read .1 or .2 across it. With you meter set to dc millivolts, and flame present on the pilot, read across the thermocouple wires (red and white) to see the millivolts generated, with the thermostat off and the gas valve in pilot position you should get approx 600 millivolt plus minus 50. The pilot will have to be on for a minute or so to get maximum millivolts. If the millivolts are correct, hi-limit closed, and all wiring is connected, you likely have a faulty gas valve. If the hi limit reads more than .1 or .2 replace the limit, if you are not getting the millivolts from the thermopile, replace it.

sounds like you need to replace the thermopile, which would make this a milli-volt system

Hello,
Typically, when a pilot won't stay lit, short of being out of gas, is a faulty thermocouple. They are fairly inexpensive and not too difficult to replace and should fix your problem. My only other suggestion, is to make sure the pilot flame is a strong blue color and is actually heating the thermocouple tip. If it's a lazy yellow flame, it may not generate enough heat to keep the pilot flame on. In this case, using a can of compressed air with attached straw (like you use to clean computer keyboards) is needed to blow out the dust or spiderweb that is clogging the pilot orifice in the pilot assembly, which is the place where the pilot flame burns. Hope this helps. Let me know if you need any more assistance. Douglas

If your pilot assembly is corroded, you will have trouble lighting the pilot.
I would highly recommend replacing the pilot assembly. By doing this, you will have a new pilot generator that will be producing a larger amount of voltage to run the gas valve. Also, you will have a clean pilot tube and orifice so gas can run unobstructed.

There should be instructions on the inside of the heater access door. Make sure you are comfortable working with gas heaters. Make sure the shutoff valve supplying gas to the heater is on. Turn the gas valve to "pilot", press and hold it while attempting to light the pilot. Once the pilot is lit, continue holding the gas valve knob down for about 30 seconds. The pilot should stay lit once you release the knob. If the pilot stay lit, turn the gas valve to "on". Replace the heater access door and make sure you have proper water flow and attempt to light the heater. If it will not light, or the pilot will not stay on, you will probably have to replace the pilot generator. It provides voltage to run the heater and after time it wears out and produces less and less voltage. A millivolt heater runs on less than one volt so any power loss can be a problem. If you are able, test the pilot generator with a multimeter to see if you are getting at least 500mv when the pilot is on. If not, you should replace the pilot generator or even the entire pilot assembly. Hope this helps...

Replace the pilot generator.

A polit generator produces about 750 MV without a load. Under load it will drop to about 200-250 MV. If the system is working don't worry about it. If the system is not working replace the pilot generator and retest. Pilot generators usually go bad slowly.

shut off the gas at the gas **** and gas valve. the pilot tube is held in place by a 7/16 compression nut. remove it then remove the 2 screws for the thermopile "generator". follow the pilot tube and the pilot assembly should be held in by one or two screws. usually you don't have to remove the main burners. hopefully this helps