Pool Heater Help

[Yit94]

Hello,
I have been procrastinating for months to fix the pool heater but now it must be done. A pool person has come to fix my system and Polaris a few times, and I mentioned the pool heater and he looked at it and said that all that had to be done was turning the ignitor on and making sure it was clean. No clue how to do that. I cant tell you the model because it is worn out, and the heater is old. But here are a few pictures, and please tell me how to
-turn it on
-turn the ignitor on
-decide if it goes to pool or spa
http://s175.photobucket.com/albums/w158/yit94/pool%20heater/
above is an album of my pcitures
please email wyattjyates@gmail.com if you need more info or pics