A.O. Smith HW 610 User Manual

48

Turn off gas supply.

Is voltage (24 Vac) across the 24 V terminals 

on module during “Call for heat”?

Turn off power supply.

Is ignition cable firmly plugged into pilot 

assembly and module?
Is ground wire firmly attached to pilot assembly and GND terminal  

on module?

Ensure ground strap is the closest metal to the igniter/sensor 

rod (electrode) to prevent the spark from shorting out to other 

metal parts (pilot screen, pilot shield, etc.).

Ignition cable must not touch metal surfaces or current 

carrying wires.
Is there a 1/8” gap between ground strap and electrode?

Is the ceramic insulator surrounding the electrode  

cracked or broken?

Replace pilot burner assembly.

Replace ignition module.

Turn on gas supply.

Turn on power supply.

Securely connect cable

and/or ground wire.

Carefully bend downward

top of ground strap

to achieve 1/8” 

spark gap.

Replace Ignition

Module.

Is voltage (24 Vac) across the PV & MV/PV terminals on

“call for heat”?

NOTE: S8610M will automatically reset every 5 minutes.  S8600H 

pilot valve will be de-energized if module goes into lockout 

condition. Reset system by turning electrical power off or by 

turning system controller to off or down below "call for heat". Wait 

one minute, then turn system on. 

Are ignition cable and ground wire in good condition

(not brittle, burnt or cracked)?

Replace pilot burner

 and/or ground wire.