Johnson Controls G77 Series Installation Sheets Manual page 16

Service
Checkout
Procedures
If the system does not function properly, determine the cause using the
procedures in this section.
Preliminary Before proceeding with troubleshooting the system, check the following:
Checks
• Are all mechanical and electrical connections tight?
• Is the system wired correctly?
• Is gas inlet pressure per manufacturer's specifications?
• Is the system powered?
• Is the thermostat calling for heat?
• Is the optional LED flashing? If so, the control is in recycle mode or it
• Is the optional LED off? If so, the control is not receiving power, or it
Failure There are three potential system failure conditions:
Conditions and
• No spark present, and system does not work.
Corrective
Action
• Spark is present, but pilot does not light.
• Pilot lights, but main burner does not come on.
Determine the failure condition, then use the respective flowchart on the
following pages to troubleshoot the system. Perform the procedures in the
Checkout and Startup Procedure section after any servicing.
16 GG77x Intermittent Pilot Ignition Controls Technical Bulletin
All manuals and user guides at all-guides.com
!
WARNING: Fire or Explosion Hazard. Do not attempt servicing
or troubleshooting when the LED is flashing (recycle
mode or ignition lockout). The control automatically
energizes the system and could cause personal injury
or property damage.
has entered an ignition lockout.
has detected a fault. Faults are:
- flame present for more than 30 seconds at call for heat
- a defective control