I've been trying to trouble-shoot my heater. I was able to conclude the ignition module is not producing a spark. I confirmed the automatic gas valve is working properly, putting 24V to the PV and MV, I can get the gas to turn on. Now I dont know if the pilot is working. Does anyone know how to get at the pilot without pulling out the entire burner assembly. The service union is rather rusted tight, I cant seem to budge it. This is a 400K teledyne laars XE heater. rather old, but I want to get it working rather than spending $2K+ to replace one.

I can get the ignition module for about $70. The pressure switch is good, limit switches are closed. So only thing is the pilot is not firing. I'm also not sure if the pilot tubing is clear.

Any help from someone who is an expert in servicing pool heaters?

It should have a bracket attached to it and you remove the screws, if they aren't rusted in place.