Burnham 8HE Series Installation, Operating And Service Instructions page 39

8
Service
(continued)
Start
Before troubleshooting,
familiarize yourself with the
Startup and Checkout
procedures.
Turn gas supply off.
Turn thermostat
(controller) to
"Call For Heat".
Power to
module? (24 V
normal)
Yes
30 second
prepurge
delay? (S8670
Only)
Yes
Spark
across ignitor/
sensor gap?
Yes
Turn gas supply on and
recycle "Call For Heat"
Pilot burner
lights?
Yes
Spark stops
when pilot
is lit?
Yes
Main burner
lights?
Yes
System runs
until "Call For
Heat" ends?
Yes
"Call For Heat" ends
System
shuts off?
Yes
Repeat procedure until
trouble free operation
is obtained.
111828-01 - 1/23
Note: "Call for heat" 24 VAC supply is connected to the 24 V terminal on the control.
Check line voltage power, low voltage transformer, limit controller, thermostat (controller) and wiring. Also,
No check air proving switch on combustion air blower system (if used) and the the vent damper end switch (if used)
is made.
No Replace S8670
Pull ignition lead and
check spark at module.
No
Check ignition cable, ground wiring, ceramic insulator and spark gap and correct.
Check boot of the ignition cable for signs of melting or buckling. Take protective action to shield cable and boot
from excessive temperatures.
Check that all manual gas valves are open, supply tubing and pressures are good, and pilot burner orifice is not
blocked (pilot gas flowing).
Check electrical connections between module and pilot operator on gas control.
No
Check for 24 VAC across PV-MV/PV terminals on module, if voltage is OK, replace gas control. If not, replace
module.
Note: It may be necessary to recycle the "Call For Heat" more than once to clear the pilot supply tubes of air.
Note: If control goes into lockout or retry delay, reset the "Call For Heat".
Check continuity of ignition cable and ground wire.
Clean flame rod.
Check electrical connections between flame rod and module.
No
Check for cracked ceramic flame rod insulator.
Check that pilot flame covers flame rod and is steady and blue.
Adjust pilot flame.
If problem persists, replace module.
Check for 24 VAC across PV-MV/PV terminals on module. If no voltage, replace module.
No Check electrical connections between module and gas control including safety controls wired in the circuit. If
okay, replace gas control.
Note: If control goes into lockout or retry delay, reset the "Call For Heat".
Check continuity of ignition cable and ground wire.
Note: If ground is poor or erratic, shutdowns may occur occasionally even though operation is normal at the time
of checkout.
Check that pilot flame covers flame rod and is steady and blue. Pilot flame must not be moving around due to
No
outside air flows, etc.
Adjust pilot flame. Check gas pressure meets appliance specifications while appliance main burner is on and all
other gas appliances on the supply are operating at full rate.
If checks are okay, replace module.
Check for proper thermostat (controller) operation.
No
Remove MV lead at module. If valve closes, recheck temperature controller and wiring. If not, replace gas control.
Figure 8-6: Trouble Shooting Guide
8HE Installation, Operating & Service Instructions
Replace module
Spark OK? No
Yes
39