Service Manual

Inspect the area housing the combustion
system and control panel located at the
top of the heater.
Does the area show signs of corrosion
and/or exssesive heat?
Y
N
Call for
technical support
Remove combustion assembly
(see “Combustion System
Removal Procedure”)
Inspect combustion chamber
for blockage or debris
accumulation
N
Replace
exhaust pressure switch.
(see “Exhaust Pressure Switch
Replacement Procedure”)
Is exhaust venting
s
ystem blocked or
obstructed?
Clear obstruction.
D
etermine cause
and correct.
Y
Is vent system total
length compliant with
v
ent tables in the
instruction manual?
R
econfigure vent
system to be
compliant with
vent tables (see
“
Specifications”).
Y
N
W
ith monometer, take a
reading at the exhaust
tube pressure tap location.
Is value negative (-)?
(see illustration below).
Check exhaust collector pressure at the exhaust
collector pressure tap location (see illustration below). Is
t
here positive pressure equal to or greater than
pressure switch settings below?
E
XHAUST PRESSURE SWITCH SETTINGS
EF(60,100)T199 +2.58" W.C.
EF100T150 +1.50" W.C.
(see note 1)
E
F60T150,EF100T250 +1.22" W.C.
E
F60T125 +2.08" W.C.
EF100T300 +0.55" W.C.
(
see note 2)
Note 1: +5.6" W.C. on serials prior to AH5039107
N
ote 2: +0.8" W.C. on serials prior to AK5288269
Y
N
Y
Y
N
N
Clear obstruction.
Determine cause
and correct.
Check Collector Pressure
Call for
technical support
Service Procedure EF-VI
Exhaust Pressure Switch Testing and Replacement
For serial numbers prior to “CF”
Exhaust Tube
pressure tap location
Exhaust collector
pressure tap location
Exhaust tube
at bottom of water
heater
55
55