Yes it uses a DSI (Direct Spark Ignition) to light the propane flame
Turn on/off switch ON and when water temp is ~110*F the T-stat closes allowing DC to go to gas valve solenoids and spark electrode
Couple of suggestions:
*Remove all connections and clean them up then reinstall making sure you have clean/tight contact.
Start with the 6 pin connector at top of circuit bd
Brown wires to/from T-stat, Red wires to/from ECO--gas valve solenoids/black wires to ground, High tension wire from transformer to spark electrode,
**Brown wires on T-stat are BACKWARDS
Brown wire from on/off switch with the 'Thermal Fuse' (clear tubing) goes TO the T-stat (right side terminal)
Then Brown wire from T-stat (Left terminal) goes to circuit bd
Right side terminal is INPUT side.
When T-stat Opens to stop heating cycle the DC stops AT T-stat input
Thermal Fuse (Clear Tubing) BLOWS if a blow-back should occur (flame coming back out combustion chamber). When it BLOWS all DC is stopped on Input side of T-stat.
SO...when cleaning up the terminals/spade connectors on T-stat/Brown wires....swap them
Normal T-stat....OPENS at 140*F to stop heating cycle/CLOSES at 110*F to allow for reheating
ECO (Energy Cut Off--High Temp T-stat)....OPENS at 180*F/shuts down ALL heating due to T-stat failing and triggers RED Fault Light. Manual reset by turning On/Off Switch OFF then back ON
Thermal Fuse....BLOWS at 190*F if flame comes back outside the chamber. One shot device/have to replace if it blows
RED Fault Light is also triggered if flame fails to light/prove it lit
Flame generates a milliamp signal when it lights off. This milliamp signal returns to circuit bd via Spark Electrode
So connections have to be Clean/tight and spark electrode needs to be free of carbon/soot
Here is the wire diagram for the 8E models