6 720 607 909
6
Appliance details
To remove combustion cover (service only)
B
Open the four clips and remove the combustion
cover.
Fig. 4
Remove the combustion cover
The GWH-345/450-ESR is not approved or
designed for:
• Manufactured (mobile) homes, RV's or boats.
(Modular homes are acceptable for installation).
• Outdoor installation
• Combination venting with other appliances
• Closed loop heating applications
• Use above 8,000 ft A.S.L. altitude.
2.4
General rules to follow for safe
operation
1. You must follow these instructions when you install
your heater. In the United States: The installation
must conform with local codes or, in the absence of
local codes, the National Fuel Gas Code ANSI
Z223.1/NFPA 54.
In Canada: The Installation must conform with CGA
B149.(1,2) INSTALLATION CODES and /or local
installation codes.
2. Carefully plan where you install the heater. Correct
combustion air supply and vent pipe installation are
very important. If not installed correctly, fatal
accidents can be caused by lack of air, carbon
monoxide poisoning or fire.
3. When the unit is installed indoors with ROOM
SEALED (twin pipe) combustion air and venting, it is
permitted to be located in bathrooms, bedrooms and
occupied rooms that are normally kept closed. See
chapter 3.6. If the unit will be installed indoors and
use indoor combustion air, the place where you
install the heater must have enough ventilation. The
National Fire Codes do not allow UNSEALED gas
fired water heater installations in bathrooms,
bedrooms or any occupied rooms normally kept
closed. See chapter 3.2 and 3.5.
4. You must vent your heater. See chapter 3.6 Venting.
5. The appliance and its gas connection must be leak
tested before placing the appliance in operation. The
appliance must be isolated from the gas supply
piping system by closing its individual manual gas
shutoff valve (not supplied with heater) during any
pressure testing at pressures in excess of ½ Psig
(3.5 kPa).
6. Keep water heater area clear and free from
combustibles and flammable liquids. Do not locate
the heater over any material which might burn.
7. Correct gas pressure is critical for the optimum
operation of this heater. Gas piping must be sized to
provide the required pressure at the maximum output
of the heater, while all the other gas appliances are in
operation. Check with your local gas supplier, and
see the section on connecting the gas supply.
8. Should overheating occur or the gas supply fails to
shut off, turn off the gas supply at the manual gas
shut off valve, on the gas line. Note: manual gas
shutoff valve is not supplied with the heater.
9. Do not use this appliance if any part has been
underwater. Immediately call a qualified service
technician to inspect the appliance and to replace
any part of the control system and any gas control
which has been underwater.
10. Failure to install heater correctly may lead to unsafe
operation and void the warranty.
11. If the heater is installed in an area where
temperatures are below 42°F, the heater will activate
to prevent freezing.
The piping outside the
appliance will not be protected.
See Chapter 4.7
for additional freeze prevention information.
12. In areas where water supply has a high mineral
content, a water softener is strongly recommended.
A water softener is required if the water hardness
exceeds 6 grains/gal (103 mg/l) calcium carbonate.
Damage to the water heater resulting from hard
water/scale deposits will not be covered under
warranty.
