Specifications

Part number 550-100-090/0809
107
g a s -f i r e d w a t e r b o i l e r — Boiler Manual
MAINTENANCE & SPECIFICATIONS
Display
Condition Diagnostics Corrective Action(s)
GAS VALVE
FAULT
The U-Control has detected
a problem with it gas valve
output circuit
Reset using manual reset screen
on display
Check wire harness connections between gas valve and U-Control.
Check resistance between
If lockout reoccurs replace U-Control.
AIR PRESSURE
SW FAULT
Air Pressure switch is open Ultra residential boilers do not
use an air pressure switch, but
instead have a wire jumper
installed between P7 pins 4 & 5.
Reset using manual reset screen
on display
Check boiler size selected in U-Control against boiler rating label. Correct
if necessary to select the proper boiler size.
Check the P7 connection as seen on Figures 97 & 98 to determine proper
jumper wire location.
GAS PRESSURE
SW FAULT
Gas pressure switch is open
(high or low)
Residential Ultra Boilers do
not use gas pressure switches.
Requires manual reset.
Check boiler size selected in U-Control against boiler rating label. Correct
if necessary to select the proper boiler size.
HW FAULT
EXPANSION
BRD
Expansion Control Board
hardware has failed.
Residential Ultra Boilers do not
use an Expansion Control Board.
Requires manual reset.
Check boiler size selected in U-Control against boiler rating label. Correct
if necessary to select the proper boiler size.
GV FAULT
EXPANSION
BRD
Gas valve ouput of the
Expansion Board
Residential Ultra Boilers do not
use an Expansion Control Board.
Requires manual reset.
Check boiler size selected in U-Control against boiler rating label. Correct
if necessary to select the proper boiler size.
EXP BOARD
COM FAULT
Communication between the
Expansion Control Board and
the U-Control Board has failed
Residential Ultra Boilers do not
use an Expansion Control Board.
Requires manual reset.
Check boiler size selected in U-Control against boiler rating label. Correct
if necessary to select the proper boiler size.
Troubleshooting (continued)
Figure 112 Troubleshooting suggestions for Ultra boilers (continued)