hi i have a laars lite 2 propane heater,its the lg series.it has the millivolt heater.i have a pilot light,but cannot get the main burner too come on.i tried jumping it at the gas valve did not work.i have tried jumping all the controls.what should i check for? how many ohms should the gas valve have>im not too familiar with millivolt systems.please let me know what 2 check for, and how to do it.on the gas valve im not familiar with the letters.what is pp/th, th, pp. meen?? thanxs steve.