31
6.
“P-SW”, “OPEN”, and “CLEAN SCREEN” Flashing
The air pressure switch contacts
remain open longer than 5
seconds after the combustion fan
is energized.
1. Clean the screen on the combustion air
intake tube. Retest, if the problem
persists:
2. Ensure the pressure switch sensing tube
is in good condition and securely
connected at both ends.
3. Ensure the inner door to the combustion
chamber is secure and the gasket is
properly sealing.
4. Take a pressure reading from the
pressure switch’s sensing point on the
inner door with a digital manometer.
A. If actual pressure reaches design
“make-point” for the switch check
pressure switch contacts continuity
with the combustion fan running. If
switch contacts remain open replace
switch.
B. If pressure does not reach “make-
point” check system for restrictions
and cleanliness.
7.
“P-SW” and “SHORT” Flashing
The air pressure switch contacts
remain closed for more than 5
seconds when they should be
open.
1. Turn off power to the water hater.
2. Locate the pressure switch wiring –
ensure pressure switch wiring is correct
and not jumped.
3. Remove wires to both terminals on
pressure switch.
4. Check pressure switch contacts with an
ohmmeter for continuity.
A.
If pressure switch contacts show
continuity (closed circuit) replace
the pressure switch.
B. If pressure switch contacts show
open circuit and all wiring is correct
– replace the lower control.
8.
“IGN” Flashing
Open ignitor circuit
1. Check all wiring to the hot surface ignitor.
2. Check the 3 pin Molex ignitor assembly
plug and receptacle on the lower control
for a good connection. Repair or replace
parts if necessary.
3. Check resistance of the ignitor with an
ohmmeter on the ignitor assembly plug.
Replace ignitor if resistance is not within
1.38 and 2.31 ohms.
4. If above checks are good – turn off
power for 10 seconds and then back on.
If this error code will not clear and the
ignitor resistance is within specifications
– replace the lower control.
9.
“FV-SENSE” Flashing
Flammable Vapor Sensor has
detected the presence of
flammable vapors and is in lockout
1. Contact a service agency to determine
the cause.
CONTROL DISPLAY STATUS
PROBLEM
SOLUTION
10.
“LDO-SW”, “OPEN”, and “CLEAN SCREEN”
Flashing
1. Clean the screen on the combustion air
intake tube. Retest, if the problem
persists:
The air pressure switch contacts
remain open longer than 5
seconds after the combustion fan
is energized.
cont.
