American Water Heater 40 Gallon 36000 BTU UltraLow Nox Direct Vent Natural Gas Water Heater DVUG6240S36NV user manual

11
Inner Wall 
PlateScrews 
& Sealant
Outer 
Wall
Plate
HOTScrews
Vent Cap
ScrewsSealantSlope down 1/4” 
per foot
Figure 7
Vertical Installation
9.  Position and fasten the inner wall plate to the inside 
wall using an appropriate fastener for the specific wall  
construction.  Apply silicone sealant between the inner  
wall plate and the inside wall.  
10.  Make certain the 5” telescoping pipe has been fully  
engaged onto the 5 inch elbow.  Drill two 1/8” holes 
180° apart at the junction of the two...

12
Vent Cap Termination
The termination of the vent cap must be in accordance 
with the local code or the authority having jurisdiction, or 
in the absence of such, the National Fuel Gas Code, ANSI 
Z223.1, NFPA 54, Current Edition.
Carbon Monoxide Hazard
Follow all instructions to locate and install 
vent cap terminal.
Instructions can be found in this manual, in 
state and local codes (or the authority 
having jurisdiction), or in the absence of 
such, the National Fuel Gas Code, ANSI 
Z223.1, NFPA 54,...

13
Water System Piping
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.
The water supply pressure should not exceed 80 psi. If this 
occurs, a pressure reducing valve with a bypass should be 
installed in the cold water inlet line. This should be placed 
on the supply to the entire house in order to maintain equal...

14 Please note the following: 
•  The system should be installed only with piping that is 
suitable for potable (drinkable) water such as copper, 
CPVC, or polybutylene. This water heater must not be 
installed using iron piping or PVC water piping.
•  Use only pumps, valves, or fittings that are compatible 
with potable water.
•  Use only full flow ball or gate valves. The use of valves 
that may cause excessive restriction to water flow is 
not recommended.  
•  Use only 95/5 tin-antimony or other...

15
Temperature and Pressure 
Relief Valve
For protection against excessive pressures and 
temperatures, a temperature and pressure relief valve must 
be installed in the opening marked “T & P RELIEF VALVE” 
(see Figure 14A). This valve must be design certified by 
a nationally recognized testing laboratory that maintains 
periodic inspection of the production of listed equipment or 
materials as meeting the requirements for Relief Valves and 
Automatic Shut-off Devices for Hot Water Supply Systems, 
ANSI...

16
Special Applications
Combination Space Heating/Potable 
Water System
Some water heater models are equipped with inlet/
outlet  tappings  for  use  with  space  heating  applications.          
Note: This water heater is suitable for combination water 
(potable) heating and space heating and not suitable for 
space heating applications only. If this water heater is to be 
used to supply both space heating and potable (drinking 
water), the instructions listed below must be followed.
•  Be sure to...

17
Water Heater Location
Water heater location is important and can affect system 
performance. Please check the following:
□   Installation area free of corrosive elements and 
flammable materials.
□   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...

18
OPERATING YOUR WATER HEATER
Lighting Instructions
Read and understand these directions thoroughly before 
attempting to light or re-light the pilot. Make sure the 
viewport is not missing or damaged. (See Figure 23) 
Make sure the tank is completely filled with water before 
lighting the pilot. 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,...

19
Burner Flames
Inspect the burner flames through the viewport. Flames 
should be very small with a blue haze and small amounts 
of yellow or orange at the edges. After several minutes 
of operation, the burner screen may glow red. If large 
flames are observed at any time, shut-off unit and call a 
qualified person.
Water Temperature 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...

20
Water Temperature Regulation
The thermostat is adjusted to the pilot position 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 at the “HOT” 
setting. Align the knob with the desired water temperature 
as shown in Figure 18. There is a hot water scald potential 
if the thermostat is set too high. 
NOTE: Temperatures shown on the gas control valve/
thermostat are approximates. The...