John Wood Commercial - AJWS - Manual (Page 19)

Emergency Shut Down
Important: If overheating occurs or the gas supply fails to
shut off, close the manual gas supply valve and turn the gas
control knob to the off position. Turn off the electrical supply
to the unit and close the cold water supply valve. Do not
operate the water heater again until it has been thoroughly
checked by a qualified service technician.
Checking the Draft
After successfully lighting the water heater, allow the unit to
operate for 15 minutes and check the drafthood relief open-
ing for proper draft. Pass a match flame around the relief
opening of the drafthood (See Figure 14). A steady flame
drawn into the opening indicates proper draft. If the flame
flutters or is blown out, combustion products are escaping
from the relief opening. If this occurs, do not operate the
water heater until proper adjustments or repairs are made to
the vent pipe system.
Burner Flames
Inspect the burner flames through the viewport and com-
pare them to the drawings in Figure 15. A properly operat-
ing burner should produce a soft blue flame and be about
50mm (2 in) to 64mm (2 -1/2 in) in height. Blue tips with yel-
low inner cones are satisfactory. The tips of the flame may
have a slight yellow tint. The flame should not be all yellow
or have a sharp blue-orange colour. Contaminated air may
cause an orange coloured flame. Contact a qualified serv-
ice technician if the flame is not satisfactory.
Operational Conditions
Condensation
Moisture from the products of combustion condenses on the
tank surface and the outside jacket of the water heater and
forms drops of water which may fall onto the burner or other
hot surfaces. This will produce a “sizzling” or “frying” noise.
This condensation is normal and should not be con-
fused with a leaking tank. Condensation may increase or
decrease at different times of the year.
High efficient energy saver water heaters will produce larg-
er amounts of condensation on initial start up or when a
large amount of hot water is being used. Do not confuse
this with a “tank leak”. Once the water reaches a temper-
ature of 49°C (120°F) and the tank warms up (usually 1-2
hours), the condensation will stop.
Important: It is always recommended that a suitable drain
pan be installed under the water heater to protect the area
from water damage resulting from normal condensation
production, a leaking tank or piping connections. Under no
circumstances is the manufacturer to be held responsible
for any water damage in connection with this water heater.
Water Heater Sounds
During the normal operation of the water heater sounds or
noises may be heard. These noises are common and may
result from the following:
1.
Normal expansion and contraction of metal parts during
periods of heat-up and cool-down.
2. Condensation causes sizzling and popping within the
burner area and should be considered normal.
3. Sediment buildup in the tank bottom will create varying
amounts of noise and may cause premature tank fail-
ure. Drain and flush the tank as directed under
“Draining and Flushing”.
Smoke/Odour
The water heater may give off a small amount of smoke
and odour during the initial start-up of the unit. This is due
to the burning off of oil from metal parts of a new unit and
will disappear after a few minutes of operation.
Safety Shut-off
This water heater is designed to automatically shut-off in the
event of the following:
1.
The pilot flame is extinguished for any reason.
2. The water temperature exceeds 96°C (205°F).
19
Burn Hazard
WARNING
Do not touch vent.
Doing so can result in burns.
Figure 14: Vent Draft Test
2 - 2 1/2”
Figure 15: Pilot/Burner Flame
50 - 64mm (2 - 2 1/2 in)