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20
Troubleshooting
– e. Verify that gas shut off valves are open. Gas
must be supplied to heater.
– f. Measure gas pressure at inlet tap with manome-
ter. See service bulletin CT-04.
– g. If no gas is present, Maxitrol regulator supplied
with heater may be upside down or locked. Rein-
stall correctly or unlock regulator (see Bulletin CT-
14). Measure gas pressure on gas line before
Maxitrol. If over 14", Maxitrol should lock up to pre-
vent high gas pressure from damaging heater.
– h. Check for tight and clean wire connections to
pilot and burner electrovalves. Remove connector
and clean with pencil eraser if dirty or corroded.
– i. Check pilot electrovalve function: Turn off gas
supply to heater, remove wire connection from
electrovalve, connect positive terminal from a sin-
gle cell battery (1.2-1.5VDC) to electrovalve termi-
nal and a jumper wire from negative terminal of
battery to ground. When connection is complete,
there should be an audible "click" from the electro-
valve. If no click is heard, electrovalve may be
faulty.
• 2. If pilot and burners light:
– a. Check for drafts around pilot burner. See Bulle-
tin CT-03 but apply smoke to pilot burner without
heater operating. If smoke is blown away from pilot
burner, find cause of draft and correct.
– b. If an AQ4 powervent is installed:
– I. Check for presence of time delay in powervent.
If there is no time delay, replace with newer style
AQ4 powervent with time delay.
– II. If powervent has time delay, check for correct
setting (2 seconds).
– III. Check for adequate minimum vent length. Refer
to AQ4 Installation Manual.
6.4
Pilot lights, but burners will not
come on.
1. Verify that gas type indicated in the rating sticker
located on the cover's right hand side, coincides with
the gas type you are using. NG is a natural gas unit and
LP is for liquid propane (See chapter 2.2).
2. Pilot flame should be blue in color and completely
engulfing the flame sensor. If not, the pilot orifice may be
dirty or clogged. See chapter 5.3 on how to clean the
pilot and orifice.
3. If sparking does not stop when pilot is lit, the flame
sensor may not be recognizing pilot flame. Verify that
wire connection clip on wire from the bottom of the
flame sensor is secure. If flame sensor is fully engulfed
by the pilot flame, it may be dirty. Clean entire surface
area of flame sensor with a pencil eraser or fine steel
wool.
4. Confirm that wire connection to the burner
electrovalve is secure (see components diagram for
location of burner electrovalve). Inspect terminals for
corrosion. To clean terminals, remove the spade
connectors and clean with a pencil eraser.
5. Ignition unit, burner electrovalve or flame sensor
maybe faulty. Measure voltage from the spade
connection of the burner electrovalve to ground with
wire connected (see components diagram for location
of burner electrovalve). After the pilot lights, voltage
should read at least 1 VDC. If voltage is proper, the
burner electrovalve may be faulty. If voltage is not
proper, ignition unit may be faulty.
Fig. 26 Electrical wiring diagram
2
Spark electrode
3
Flame sensor
18
Microswitch
23
Ignition unit
25
Burner electrovalve
28
Pilot electrovalve
31
Temperature limiter/ECO
32
Flue gas sensor
33
Gas valve
34
Main burner operation LED
35
On/Off button
50
Hydrogenerator
111
Temperature limiter/ECO
6.5
Main burners go out during hot
water use
1. Hot water flow rate is dropping below required
activation flow rate. Turn flow control knob all the way
clockwise. Fully open a hot water faucet and fill a quart
container. If the container fills in 36 seconds or less, the
flow rate (0.5 gallon per minute) is sufficient to activate
the water heater. If flow rate is not sufficient, the water
heater's inlet filter should be inspected and cleaned.
See chapter 5.2.
2. Close installer supplied cold water shut off valve (if
none installed, install before proceeding). Open every
hot water tap supplied by the heater. Wait 5 minutes
and check all taps. Any water running, even a trickle, is
a sign of a plumbing crossover. Consult local plumber
