General Information - Atwood OD50 Operating & Maintenance Instructions

GAS VALVE
WIRING
SCHEMATIC
MPD 90211
HOW TO OPerATe yOUr WATer HeATer
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• DO NOT smoke or have any flame near an open faucet.
If water heater has not been used for more than two weeks,
hydrogen gas may form in water line. Under these conditions
to reduce the risk of injury, open hot water faucet for several
minutes at kitchen sink before you use any electrical appliance
connected to hot water system.
If hydrogen gas is present, you will probably hear sounds like air
escaping through the pipe as water begins to flow.
1) Pressurize the water system by turning on pump or city
water pressure.
2) Purge all air from the system by turning on the faucets
until a steady stream of water flows.
3) Turn on the 12V DC power supply.
4) Turn on the LP supply at the tank and the manual gas
valve (if installed). The water heater will remain dormant
until a water tap is opened and the heater senses water
flow of at least 0.5 GPM.
5) Turn on the hot water tap to full open. The heater will fire
up within several seconds and hot water will flow from the
tap in the time it takes to traverse the lines from the heater
to the faucet. (If this is the first usage, you may have to
turn the water on and off several times to purge the LP
gas lines of air.) If the heater fails to light or the lockout
lamp (optional) illuminates, turn the power switch OFF,
then On to reset the ignition control.
6) To shut off the water heater, shut off the water.
7) Should overheating occur or the gas supply fail to shut off,
turn off the "On/OF" power switch.
a note about "navy showers" When Dry camping
It is recommended to take a shower just like you would at
home. That is, leave the water running through the entire
shower. The hot water system is designed to deliver a
continuous, comfortable flow of hot water and that's the way it
works best.
Shutting off the shower with the showerhead button wastes
water. Each time this is done, the showerhead "trickles", filling
the hot water line with cold water. This cold water has to be
purged from the line each time the showerhead is turned back
on. Tests have shown that this will not save water.
(BROWN)
(GREEN)
IGN. CONT
SPARK & SENSE
caution
FirE
(RED)
PRESSURE SWITCH
(RED)
ECO
RELAY
COLD PACK
(OPTIONAL)

General informaTion

• LP and Water system must be turned on.
• Have gas pressure tested periodically. Should be set at 11
inches of water column with three appliances running.
• Drain water heater at regular intervals (at least one time
during the year).
• Drain water heater before storing RV for the winter or when
the possibility of freezing exists.
• Keep vent and combustion air grill clear of any
obstructions.
elecTronic iGniTion mainTenance
• The water heater comes factory-equipped with an in line
fuse, which will protect the circuit board from wiring shorts.
If the fuse should blow, the water heater will not operate.
Before replacing the fuse, check for a short external to the
board. Once the short is corrected, replace the 3 amp fuse.
Do not install a fuse larger than 3 amps.
• If the fuse is good and the unit is inoperative, check for
excessively high voltage to the unit (more than 14 volts).
moDulaTinG valve aDJusTmenT:
The modulating water valve will have a factory preset setting
which is designed and tested for an approximate 65°F rise in
temperature for a hot water flow rate ranging from 1.00 GPM
to 1.25 GPM as measured at the water outlet (ie. faucet or
shower head). Pictures of this valve adjustment are on the
next page. The consumer is encouraged to set the modulating
valve to provide hot water in the 110°F-115°F range. The
consumer can then add cold water to achieve the desired
hot water temperature. Care must be taken to prevent higher
temperatures which may result in scalding.
The factory setting will satisfy most applications, however the
modulating water valve has been designed with flexibility in
mind to handle a wide range of diverse situations. For hotter
water temperatures the modulating valve can be adjusted
counter-clockwise toward the MAX position; for cooler hot
water temperatures, the modulating valve can be adjusted
clockwise toward the MIN position. One should use caution
not to force the valve adjustment beyond the MAX and MIN
points.
• Consult Owner's Manual before adjusting the Modulating
Valve.
4
(BLUE)
LOCKOUT
LAMP
(RED)
(OPTIONAL)
PROX
(PURPLE)
FREEZE
(RED)
+ 12V DC
FUSE
(BLUE)
GROUND
(GREEN)
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caution