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“LO” Code
Verify adequate
water flow, is
flow sufficient?
Is water pressure
switch wiring free of
damage?
YES
NO
46
Increase flow
rate/clean filter
11. Service LED ON: “LO” Code
YES
Replace wire
harness:
FDXLWHA1930
NO
Check continuity of
water pressure
switch, is continuity
present?
NO
Replace water
pressure switch:
FDXLWPS1930
YES
Adjust switch
if necessary
Did error
clear?
Problem
solved
YES
Verify high
limit wires
are free of
damage
NO
Are wires free
of damage?
Replace high
limits kit:
FDXLHLI1930
NO
YES
Is this heater
installed
indoors?
YES
Go to
section B
(next page)
NO
Heater made
after Feb.
2016?
YES
NO
Contact
Support
(908) 355-7995
YES
Does exhaust
gas limit have
continuity?
Replace exhaust
gas limit switch:
FDXLEGL1930
NO
Summary of Contents for H150FDN
Page 12: ...Universal H Series Heaters How To ...
Page 18: ...Universal H Series Heaters Troubleshooting ...
Page 64: ...64 ...
Page 65: ...Wiring Connection Diagram 65 ...