Table 4-2. Unit Troubleshooting - CONT.
TEST OR INSPECTION
Step 1. Remove burner cover (page 295) and check adjustment of head and air setting.
Adjust head and air setting (page 4-232).
Remove rings, bracelets, wristwatches, and neck chains before working on any vehicle. Jewelry can
catch on equipment and cause injury, or may short across an electrical circuit and cause severe burns or
Step 2. Remove two screws and cover and check for 120 Vdc at low fire hold switch while in OUT position.
If 120 Vdc are present, replace damper motor (page 4-268).
If 120 Vdc are not present, replace burner controller (page 4-275).