51
Screen Display
Explanation
Go to Page For
Troubleshooting
Control has blocking error for more than 20
hours in a row.
Go to Page 53
Three unsuccessful ignition attempts in a row
Go to Page 54
Open gas valve power circuit. May involve
high temperature switch, gas valve, or gas
valve relay in control module.
Go to Page 53
Safety Circuit is open.
Go to Page 55
Blower speed does not reach speed calculated
by Control Module.
Go to Page 56
Control Module internal error.
Replace Control
Module
High Temperature opens during normal
operation.
Go to Page 57
Control Module detects flame after gas valve
is closed more than 10 seconds.
Replace Gas Valve
Flame is detected before gas valve opens.
Replace Gas Valve
Control module internal error.
Replace Control
Module
Lost flame signal 3 times during one heat call.
Go to Page 58
Control Module internal error.
Replace Control
Module
Control Module internal error.
Replace Control
Module
External voltage supplied to DHW T-T or CH
T-T terminals. Eliminate voltage using dry
contact relay.
-
Flame detected when gas valve is closed.
Go to Page 58
B l o c k i n g E r r o r
R E F L O t o o L O
13 - TROUBLE SHOOTING
PN 240011320 Rev. G 10/01/2021]