Weil-McLain SVF 1500 Manual page 107

SVF
™
Series 1
Commercial Condensing Gas-Fired Water Boiler — Boiler Manual
Troubleshooting
Figure 102 Troubleshooting suggestions for
Display
Condition
HW FAULT Expansion Control Board
EXPANSION
hardware has failed.
BRD
GV FAULT Gas valve output of the
EXPANSION
Expansion module.
BRD
EXP BOARD Expansion Control Board
COM FAULT
communication fault.
Occurs when micro-controllers
Hardware Fault
on main board have a RAM or
ROM error, or communication
is cut off.
Hardware
The control has detected a
Fault 1,2,3,4 problem with its gas valve
output circuit.
Closure
Closure switch connections
on P7 Pins 2 and 3 are open
for more than 4 minutes.
OUTDOOR Outdoor temperature sensor
short or OPEN.
SENSOR ERROR
Flue Temp
Occurs if flue temperature
Too High sensor exceeds 210°F
(Warning) or 220°F (Lockout).
Part number 550-100-250/0819
(continued)
TM
SVF
boilers
(continued)
Diagnostics
Expansion Control Board has
detected an issue with it's
hardware and has locked out.
Requires a manual reset.
Expansion Control Board has
detected an issue with the gas
valve circuit. Requires a manual
reset.
Communication has been lost
between the Control and the
Expansion Control Board.
Check for hardware damages.
Auto reset if condition is clear
after lockout, then 1 hour
automatic reset if condition clear,
then manual reset required.
Soft lockout when 4 minute
timer expires. Reset when
closure is made.
Will automatically reset if the
condition clears.
Warning only. Supply Max is
targeted until ODT is restored, if
used for target adjustment.
Automatic reset occurs if
temperature drops below 210°F
for 2 ½ minutes.
Manual reset is required if the
temperature rises above 220°F.
Reset using manual reset screen
on display.
Corrective Action(s)
Check boiler size selected in Control against boiler rating label. Correct if
necessary to select the proper boiler size.
Check the wire harnesses between the Control, Expansion module, and
gas valve.
Check the communication wire harness between the two controls.
RAM or ROM errors can be reset with the manual reset option.
If problems persist, replace main board.
Check for physical damages.
Check connections to gas valve and gas pressure.
If problem persists, replace main board.
None – Check jumper on correct pins and secure connection.
Flow switch attached – Check correct pump is on, check wiring to flow
switch, and check switch is closing.
CAD – Check voltage to damper. Check damper is opening.
Determine which sensors are suspect and measure their resistance
value and compare it to the values shown in Figure 100, page 101. If the
resistance values are incorrect replace the temperature sensor. Refer to
repair parts section for proper part number.
Check wire harness for loose connections and pin engagement at sensor
connection, chassis mount connection through control housing, and
the control. Unplug connection at sensor and at control and check
continuity between ends.
If problem persists after checking items above, replace control. Refer to
repair parts section for kit number.
Follow procedure above for SHORT and OPEN sensor conditions
to properly diagnose sensor. In addition inspect heat exchanger
combustion chamber and flue-ways for abnormal wear and buildup.
Inspect vent system for abnormal wear or damage.
Contact Weil-McLain Technical Support.
107