18
Checking the Draft
Burn Hazard
Do not touch vent.
Doing so can result in
burns.
After successfully lighting the water heater, allow the unit
to operate for 15 minutes and check the drafthood relief
opening for proper draft. Make sure all other appliances
in the area are operating and
all doors are closed when
performing the draft test. Pass
a match flame around the relief
opening of the drafthood. 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 compare
them to the drawings
in Figure 18. A properly
operating burner should
produce a soft blue
flame. Blue tips with
yellow 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
color. Contaminated air may cause an orange colored
flame. Contact a qualified service technician if the flame is
not satisfactory.
Stacking
Stacking occurs when a series of short draws of hot water
(3 gallons or less) are taken from the water heater tank.
This causes increased cycling of the burner and can result
in increased water temperatures at the hot water outlet. An
anti-scald device is recommended in the hot water supply
line to reduce the risk of scald injury.
Emergency Shut Down
Important: Should overheating occur or the gas supply fails
to shut off, turn off the water heater’s manual gas control
valve and call a qualified service technician.
Figure 17
Match
Relief
Opening
Drafthood
Figure 18
Flame Characteristics
Tips may have
a yellow tint
Yellow inner
cones are
satisfactory
Correct flame
soft blue
Water temperature over 125°F can cause
severe burns instantly or death from
scalds.
Children, disabled and elderly are at
highest risk of being scalded.
Feel water before bathing or showering.
Temperature limiting valves are
recommended.
Water Temperature Regulation
UNITROL
BEFORE
LIG
HTIN
G
RE
AD
AL
L IN
ST
RU
CT
IO
NS
CAU
TIO
N
H
O
T
W
A
R
M
V
A
C
A
T
IO
N
CA
UTION
W
A
TE
R INCREA
SE
S
HOTTER
T
H
E
RIS
K OF SCALD
IN
JU
R
Y
V
A
C
AT
IO
N
WA
RM
H
O
T
120°F
Bar
130°F
Bar
Index
Bars
Gas
Control
Knob
Figure 19
Robertshaw Gas Valve/Thermostat
Settings
W
ARN
IN
G
Dial
Stop
130°F
Bar
Reset
Button
The thermostat is adjusted to its lowest temperature when
it is shipped from the factory. Water temperature can be
regulated by moving the temperature dial to the preferred
setting.
The preferred starting point is 120°F.
Align
the index bar on the thermostat with the desired water
temperature as shown in Figure 19.
There is a hot water
scald potential if the thermostat is set too high.
Important:
Adjusting the thermostat past the 120°F bar
on the temperature dial will increase the risk of scald injury.
Hot water can produce first degree burns within:
120°F (49°C) more than 5 minutes
130°F (54°C) at 20 seconds
140°F (60°C) at 3 seconds
150°F (66°C) at 1-1/2 seconds
160°F (71°C) at less than 1 second
Note:
During low demand periods when hot water is not
being used, a lower thermostat setting will reduce energy
losses and may satisfy your normal hot water needs. If hot
water use is expected to be more than normal, a higher
thermostat setting may be required to meet the increased
demand. When leaving your home for extended periods
(vacations, etc.) turn the temperature dial to its lowest
setting. This will maintain the water at low temperatures
with minimum energy losses and prevent the tank from
freezing during cold weather.
L.P.G. (Bottled Propane) Models
Liquefi ed petroleum gas is over 50% heavier than air
and in the occurrence of a leak in the system, the gas
will settle at fl oor level. Basements, crawl spaces, skirted
areas under mobile homes (even when ventilated), closets
and areas below ground level will serve as pockets for
the accumulation of gas. Before lighting an L.P. gas water
heater, smell all around the appliance at fl oor level. If you
smell gas, follow the instructions as given in the warning on
the front page.
When your L.P. tank runs out of fuel, turn off the gas at
all gas appliances including pilot lights. After the tank is
refi lled, all appliances must be re-lit according to their
manufacturer’s instructions.
