4-5
MAINTENANCE
SL 20-115 MODULATING GAS BOILER
Outlet (supply) water temperature sensor
Upper vessel high limit switch
Vent temperature sensor bracket
Inlet (return) water temperature sensor
Ignition electrode/flame sensor
Removing vent stack test port plug
Fan coupler block
Water pressure sensor
Water temperature high limit switch
Control Module removal
Combustion air intake riser
Removing combustion air intake riser
Removing vent stack