John Wood Atmospheric Vent Light-Duty - Manual (Page 9)

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Water Temperature Regulation
The thermostat is adjusted to its lowest temperature position when
shipped from the factory. The temperature of the water can be
selected by setting of the temperature dial on the front of the gas
control. The “LOW” position on the thermostat is the preferred
starting point for setting the temperature/control knob
(approximately 120 O F(50 O C)). Energy conservation is a
consideration when selecting the water temperature setting.
HIGHER SETTING INCREASES THE RISK OF SCALD
INJURY
In households with children, the elderly or handicapped persons,
select a lower temperature setting. To reduce the risk of scalding,
valves for reducing the point of discharge water temperature by
mixing the branch water lines are available. Please consult a
licensed plumbing authority.
Performance Checks
1.Burner Manifold Pressure - The burner operates at a manifold
gas pressure of 3.5” W.C. for natural gas and 10.0” W.C. for
propane gas. A 1 / 8
” N.P.T. port is provided on the gas valve
control for connection to a gauge to measure the pressure. The
control valve has an internal pressure regulator. Do not confuse
the manifold pressure with the supply inlet pressure. Return port
plug upon completion of tests.
2.Checking Input - Never exceed input shown on the rating plate.
Ask your gas supplier for the heating value of the gas you are
using. Check the input by ”clocking” the gas meter. Make sure
no other appliances are operating when the test is being done.
To ensure accuracy, clock enough gas so that the time is greater
than 60 seconds. Use the following formula to check input.
Check that your gas pressures are as previously stated.
3.Checking burner flame - Water Heaters may use either a sheet
metal or cast iron burner. Access the burner by lifting off the
outer gas door and sliding open the inner door located at the
bottom of the water heater.
• For water heaters having a sheet metal burner and burning
natural gas, a constant, steady, soft blue flame should be visible
coming from the burner head.
• For water heaters having a sheet metal burner and burning
propane gas, the flame will be a constant, steady blue with a
brighter blue being visible right at the burner head. The very
ends of the flame may be tipped with yellow. This is more
noticeable on higher input units.
• Noisy, hard blue flames, flames lifting from the burner, luminous
or yellow stringy flames indicate an incorrect setup. Check that
the unit is using the correct gas. This information is on the rating
plate and the label on the side of the gas valve control. Poor
flames can also be caused by incorrect gas pressures or burner
orifice size, inadequate or contaminated air, a restriction in the
venting system, or dirt entering the gas supply. These conditions
must be corrected to prevent a possible safety hazard.
• For units with cast iron burners, the flame presentation should
be the same as sheet metal burners. Adjustment is possible on
cast iron burners by changing the air shutter position on the
burner inlet. If the flame needs adjusting, loosen the two screws
and move the shutter. See Figure 8. If it is too far open, the
flame will lift off the burner or will be noisy; if it is closed too far,
the flame will be luminous and yellow. Once proper flame is
obtained, tighten the screws to secure the air shutter.
NOTE: There is no means for flame adjustment on sheet metal
burners as they are self-adjusting.
IMPORTANT: Always return the burner doors
to their original position.
ALWAYS KEEP THE AREA AROUND THE WATER
HEATER CLEAR OF COMBUSTIBLE MATERIALS.
NEVER RESTRICT THE FLOW OF AIR TO THE
WATER HEATER.
VII) SERVICE AND MAINTENANCE
This section describes the routine service
instructions to properly maintain your heater and
venting system.
Not Enough or No Hot Water
• Check that the water heater is operational.
• Relight the pilot burner if necessary.
• Check that the thermostat is set high enough.
• Check that you have not just run out of hot water due to heavy
demand. If this is a routine problem, it may indicate an under-
sized water heater.
• Have your gas company check input rate and water heater
operation.
• The E.C.O. may have tripped open. See E.C.O. below.
Energy Cut-off Control (E.C.O.)
This water heater is equipped with a control which has a built in
E.C.O. (Energy Cut-Off). The E.C.O. will shut the gas off, should
the outlet water temperature exceed maximum temperatures. If
the E.C.O. has tripped, the entire gas valve/temperature control
must be replaced. For gas valve/temperature control
replacement, contact your local gas utility, or a qualified service
technician. The replacement control must be an approved
equivalent model to the control which has been removed.
Water Temperature is Too Hot
• Check that thermostat setting is not too high.
• Water heaters used for dishwashers, space heating or laundry
facilities generally require higher temperatures than domestic
use. Install anti-scald tempering valves as instructed in the
safety warnings.
• If the problem persists, contact your dealer or gas supplier.
Hot Water Odour
On occasion, and depending on your location, hot water may
develop a strong odour. This can be especially problematic in
regions where the water contains some sulphur, which results in
hot water having a “rotten egg” smell.
If this occurs, drain the system completely, flush thoroughly and
refill. If the problem persists, the anode rod may need to be
changed from magnesium to one made of aluminum. In certain
cases chlorination and flushing of the water heater may be
required. Contact you dealer or water supplier.
Input Gas Heating Value* x Cubic Feet(Meters) clocked
(BTU/Hour) = Seconds clocked/3600
*Gas Heating Value in BTU/cubic feet or cubic meters
1 cubic meter = 35.31 cubic feet
GOOD BLUE
FLAMES
Figure 8