American Water Heater 40 Gallon 42000 BTU UltraLow Nox Power Vent Natural Gas Water Heater PVUG6240T42NV User Manual

11
Vent Pipe System
This water heater must be properly vented for removal 
of exhaust gases to the outside atmosphere.  Correct 
installation of the vent pipe system is mandatory for the 
safe and efficient operation of this water heater and is an 
important factor in the life of the unit.
The vent pipe must be installed in accordance with state 
and local codes, or in the absence of such, the National 
Fuel Gas Code, NFPA 54, ANSI Z223.1-current edition.   
IMPORTANT: Check to make sure the vent pipe is...

12
Table 4 - Maximum Allowable Length in Feet of Exhaust Pipe - (42K BTU/Hr models only)
Pipe Size  (in)Number of 90° Elbows (medium or long sweep only)Termination  Options
0123456
2 40 35 30 25 20 15 10 Std. Horizontal
2 40 35 30 25 20 15 10 Vertical
3 120 115 110 105 100 95 90 Std. Horizontal
3 120 115 110 105 100 95 90 Vertical
Notes:
1. N/A - Not Applicable
2. The above maximum lengths are for outlet pipe systems. 
3. Maximum of 6 elbows may be used. Use only medium or long         
    sweep elbows....

13
Vertical Termination
The vertical exhaust outlet requires a return bend or two 
medium or long sweep radius 90° elbows to keep the 
exhaust outlet downward and prevent entry of rain. Do 
not include these elbows when calculating the maximum 
allowable vent pipe because they have already been 
considered in the vent tables. The vertical exhaust outlet 
termination is a 2 inch or 3 inch pipe which must be at 
least 12 inches above the roof line or anticipated snow 
levels. See Figure 11. 
Follow all...

14
WATER SYSTEM PIPING
FIGURE 13
Typical Mixing 
Valve Installation
Tempered Water
to fixtures
Cold
Water Inlet
Mixing Valve
(set to 120°F
 or lower)
Piping Installation
Piping, fittings, and valves should be installed according to 
the installation drawing (Figure 12). If the indoor installation 
area is subject to freezing temperatures, the water piping 
must be protected by insulation.
Water supply pressure should not exceed 80 psi. If this 
occurs, a pressure limiting valve with a bypass may need 
to...

15
Closed System/Thermal Expansion
CAUTION - PROPERTY DAMAGE HAZARD
As water is heated, it expands (thermal expansion). In a 
closed system, the volume of water will increase. As the 
volume of water increases, there will be a corresponding 
increase in water pressure due to thermal expansion. 
Thermal expansion can cause premature tank failure 
(leakage). This type of failure is not covered under the 
limited warranty. Thermal expansion can also cause 
intermittent temperature-pressure relief valve...

16
ELECTRICAL CONNECTIONS
Before plugging in the water heater, always make sure:
•  The voltage and frequency correspond to that specified on the water heater wiring diagram.
•  The electrical outlet has the proper overload fuse or  breaker protection.  IMPORTANT: Do not use an extension cord to connect the 
water heater to an electrical outlet.
•  The water heater and the outlet are properly grounded.
•  Installed in accordance with prevailing provisions of 
local codes, or in the absence of such,...

17
•  The domestic hot water line from the water heater 
should be vertical past any mixing valve or supply 
line to the air handler to remove air bubbles from the 
system. Otherwise, these bubbles will be trapped in the 
air handler heat exchanger coil, reducing the efficiency.
•  Do not connect the water heater to any system or    
  components previously used with non-potable water  
  heating appliances when used to supply potable water.
Some jurisdictions may require a backflow preventer in 
the...

18
INSTALLATION CHECKLIST
Water Heater Location
•  Centrally located with the water piping system.    
  Located as close to the gas piping and vent pipe    
  system as possible.
•  Located indoors and in a vertical position. Protected   
from freezing temperatures.
•  Proper clearances from combustible surfaces    
  maintained and not installed directly on a carpeted    
 fl oor.
•  Provisions made to protect the area from      
  water damage. Drain pan installed and piped to an    
 adequate drain.
•...

19
OPERATING YOUR WATER HEATER
Lighting Instructions
Read and understand these directions thoroughly before 
attempting to operate the water heater. Make sure the 
tank is completely filled with water before operating the 
water heater. Check the data plate near the gas control 
valve/thermostat for the correct gas. Do not use this 
water heater with any gas other than the one listed on 
the data plate. If you have any questions or doubts, 
consult your gas supplier or gas utility company.Explosion...

20
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 available.
WARNING
Water Heater Operation
Figure 15 below shows the water heater’s sequence of 
operation when a call for heat is initiated. The ignition con-
trol module will attempt to light the burner three times. If 
the ignition control does not detect ignition it will...