Vulcan-Hart GRS25 Service Manual page 10

3. Push power switch ON and immediately touch one end of the jumper firmly to the GND terminal on the
module. Do not touch the jumper to the SPARK terminal, but, move the free end of the jumper slowly towards
the SPARK terminal until a spark is established.
Pull the jumper slowly away from the SPARK terminal and note the length of the gap when the sparking stops.
See table below for results and action to be taken.
ARC LENGTH
No arc or arc less than 1/8".
Arc 1/8" or longer
If you are getting spark but the spark continues after the pilot is lit check the following.
4. Check for ground wire and ignition cable continuity.
5. Check that flame rod is clean.
6. Check for crack in ceramic insulator again.
7. Check that pilot flame covers rod and is steady and blue. Adjust pilot or pilot flame if necessary.
8. If the above are all in good condition replace module.
PILOT CHECK (Pilot will not light)
1. Check that all manual gas valves are open, that supply tubing and pressure are good and pilot orifice is not
blocked.
2. Check electrical connections between module and pilot operator on gas combo valve.
3. With volt meter check for 24Vac across PV-MV/PV terminals on module. If voltage is good replace the combo
valve. If voltage is bad replace the module.
BURNER CHECK (Main burner will not light)
1. Check for 24Vac across the MV-MV/PV terminals. If voltage is bad replace the module.
2. Check electric connection between the module and gas combo valve. If good replace the combo valve.
COMPUTER CONTROLLER DIAGNOSTIC CHECKS
The service diagnostics for the GRC Fryer computer is divided into (2) sections NORMAL and SERVICE
DIAGNOSTICS. The normal mode is the usual operating mode of the fryer. The service mode is intended to
give the service man more information regarding the nature of the system's failure.
NORMAL OPERATING MODE CHECKS:
SYSTEM PROBLEM
OR FAILURE
Ignition
Low temperature
lack of heat
High temperature
1st. limit comes on.
High temperature
2nd limit comes on.
Probe
Self-check
ACTION
Verify power at module input terminal.
Replace module if power is verified.
Voltage output is OK.
DISPLAY
IGN. FAILURE
LOW TEMP.
HIGH TEMP
CALL SERVICE
CALL SERVICE
CALL SERVICE
10
SYSTEM RESPONSE
Heat off
Heat off
Heat off
Hardware limit heat off
Heat off
System to back up mode