HTP CG300N65 - Manual (Page 14)

14
LP-436 REV. 3.21.14
Pressure Build-Up in a Water System
When the water heater operates, the heated water expands creating a pressure build-up. This is a natural function and is one of the
reasons for installing a temperature and pressure relief valve. If the cold water supply line has a built-in water meter, check valve, or
pressure-reducing valve, a suitable expansion tank must be installed to prevent pressure build-up or water hammer effect. Otherwise,
the warranty is void. See Figure 10. An indication of pressure build-up is frequent relief valve discharge. If the relief valve discharges
water on a continuous basis, it may indicate a malfunction of the relief valve and a qualified service technician must be called to have
the system checked and the problem corrected.
Filling the Water Heater
NEVER operate the water heater unless it is completely full of water. Failure to follow this instruction can result in premature failure of
the water heater. Such failure IS NOT covered by warranty.
Check that all the water piping connections have been made. To fill the water heater:
1. Make sure that the water heater drain valve is closed by turning the knob clockwise.
2. Open the cold water supply manual shut-off valve. This valve must remain open as long as the water heater is in use. NEVER
operate the water heater with the cold water supply manual shut-off valve closed.
3. To make sure the water heater is completely full of water, open hot water faucets to let the air out of the water heater and
plumbing system. Leave the faucets open until a constant flow of water is obtained.
4. Check all of the plumbing connections to make sure there are no leaks.
Gas Connections
DO NOT attempt to use this water heater with any gas other than the type shown on the water heater rating plate. Failure to follow this
instruction can result in property damage, personal injury, or death.
The gas piping must be installed as indicated in Figure 10. For the correct size of piping for this water heater, consult the National Fuel
Gas Code, ANSI Z223.1 / NFPA 54 in the United States, or CAN/CSA B149.1, National Gas and Propane Installation Code in Canada.
Only new piping with cleanly cut threads may be used, together with a suitable sealing compound that is approved for natural and
propane gases. It is mandatory that a readily accessible manual shut-off valve be installed in the gas supply line. The gas supply
manual shut-off valve must be close to the water heater. A drip leg (sediment trap) must be installed in the gas line ahead of the main
gas valve to prevent dirt from entering it. A union must be installed between the main gas valve and the gas supply manual shut-off
valve for easy maintenance of the water heater.
NEVER use an open flame to test for gas leaks. A fire or explosion could occur, resulting in property damage, personal injury, or death.
The water heater and its gas connection must be leak tested before placing the appliance into operation. To leak test the system:
1. Turn on the manual gas shut-off valve near the water heater.
2. Use a soapy water solution to test all connections and fittings for leaks. Bubbles indicate a gas leak.
3. Correct all leaks.
Make sure that the inlet pressure to the water heater does not exceed 14 inches of water column (3.5 kPa) for natural gases.
Pressures in excess of ½ pound per square inch (3.5 kPa) can damage the main gas valve, resulting in a fire or explosion from leaking
gas. For purposes of adjustment, the minimum inlet pressure is indicated on the water heater rating plate.
If any pressure testing of the gas line is undertaken at test pressures in excess of ½ psig (3.5 kPa), the water heater and its gas supply
manual shut-off valve must be disconnected from the gas supply piping system, and the end of the pipe sealed with a female cap. If the
testing is to be undertaken at a test pressure less than ½ psig (3.5 kPa), the gas supply manual shut-off valve must be closed.
NOTE: The input rating of the appliance is based on installation and operation at sea level up to elevations of 2,000 ft. Low NOx models
are certified to operate to 2,000 ft in altitude without adjustment.
High altitude orifices MUST BE installed for water heaters operating above 7,500 feet. Failure to follow this instruction can result in
property damage, personal injury, or death.
Installation Instructions for Water Heaters Approved for Combination Space Heating and Potable Water Heating
When using a water heater for combination space and potable water heating, the instructions provided in this manual and the air-
handling unit must be respected, with particular attention paid to the following: