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

21
Operating the Temperature Control System
Figure 19: Status Codes
VAC
List of status codes are shown
at top of gas control valve/thermostat.
Water Temperature Adjustment
The water temperature can be adjusted from 55°F to 155°F. 
Turn the Gas Control/Temperature Knob to the desired 
setting/temperature.
Operating Modes and Settings
• Standard Mode - The controller adjusts the water 
heater to maintain the temperature set by the user.
• Vacation Setting - The controller adjusts the water 
temperature to...

22
Operational Conditions
Condensation
Moisture from the products of combustion condenses on the 
tank surface and the outside jacket of the water heater and 
forms drops of water which may fall onto the burner or other 
hot surfaces. This will produce a “sizzling” or “frying” noise. 
NOTE: This condensation is normal and should not be 
confused with a leaking tank. Condensation may increase or 
decrease at different times of the year.
High efficient energy saver water heaters will produce 
larger...

23
MAINTENANCE OF YOUR WATER HEATER
Draining and Flushing
It is recommended that the tank be drained and flushed 
every 6 months to remove sediment which may build up 
during operation. The water heater should be drained if 
being shut down during freezing temperatures. To drain the 
tank, perform the following steps:
1.  Turn off the gas to the water heater at the manual gas 
shut-off valve.
2.  Open a nearby hot water faucet until the water is no 
longer hot.
3.  Close the cold water inlet valve.
4....

24
Replacement Parts
Replacement parts may be ordered through your plumber 
or the local distributor. Parts will be shipped at prevailing 
prices and billed accordingly. When ordering replacement 
parts, always have the following information ready:
1.  model, serial, and product number
2.  type of gas
3. item number
4. parts description
See pages 30-31 for a list of available repair parts.
Removing the Burner Door Assembly
1.  Turn off the gas to the water heater at the manual 
shut-off valve (Figure...

25
Replacing the Pilot/Thermopile Assembly
1.  Remove the burner door assembly as directed previously.
2. 
Lift the retainer clip straight up from the back of 
the manifold component block (using a flat-blade 
screwdriver), then remove the manifold component 
block from the burner door assembly
 (Figure 25).
3.  Locate and remove the phillips screw attaching the pilot to 
the pilot bracket, 
then pull the pilot/thermopile assembly 
(including the igniter wire) out of the burner door assembly.
  
4....

26 1.  Check the door gasket for damage or imbedded debris 
prior to installation.
2.  Inspect the viewport for damage and replace as required.
3.  Insert the burner door assembly into the burner 
compartment. 
4.  Inspect the door gasket and make sure there is no 
fiberglass insulation between the gasket and the 
combustion chamber.
5.  Replace the four screws which secure the burner door 
assembly to the combustion chamber and tighten 
securely. There should be no space between the 
gasket part of the...

27
Removing and Replacing the Gas 
Control Valve/Thermostat
IMPORTANT: The gas control valve/thermostat is a standard 
valve with wire leads that connect to the thermopile. 
Removing the Gas Control Valve/Thermostat:
1.  Turn the gas control/temperature knob  to the “OFF” 
position (Figure 18).
2.  Turn off the gas at the manual shut-off valve on the gas 
supply pipe (Figure 3).
3.  Drain the water heater. Refer to the section of “Draining 
and Flushing” and follow the procedure.
4.  Disconnect the...

28
PROBLEM POSSIBLE CAUSE(S) CORRECTIVE ACTION
HIGH OPERATION COSTS 1.  Thermostat set too high
2.  Sediment or lime in tank
3.  Water heater too small for job
4.  Wrong piping connections
5. Leaking faucets
6. Gas leaks
7.  Wasted hot water
8.  Long runs of exposed piping
9.  Hot water piping in exposed wall1.  Set temperature dial to lower setting
2.  Drain/flush-provide water treatment if needed
3.  Install adequate heater
4.  Correct piping-dip tube must be in cold inlet
5. Repair faucets
6.  Check...

29
STATUS LIGHT CODE TROUBLESHOOTING CHART 
LED STATUS PROBLEM CORRECTIVE ACTION
0 FLASHES (LED NOT LIT) Pilot light is not lit. Not enough 
power (millivolts) to keep it lit.Follow the lighting instructions on the front of the 
water heater and record any diagnostic codes. 
See Diagnostic Status Light Code section.
1 FLASH (EVERY 3 SECONDS) Normal operation. No corrective action necessary.
2 FLASHES Insufficient power (millivolts) to the 
gas control valve/thermostat.1.  Check all wiring connections. If...

30
REPAIR PARTS ILLUSTRATION
Item
 No.Parts Description
1 VENT CAP ASSEMBLY
2 OUTER WALL PLATE
3 INNER WALL PLATE
4 FLEX VENT PIPE (WITH CLAMPS)
5 UPPER AIR  BOX
6 4” TO 3” REDUCER
7 DRAIN VALVE
8 FLUE BAFFLE
9 DIP TUBE
10 LOWER AIR  BOX
11 SNAP IN PLUG
12 TEMPERATURE & PRESSURE RELIEF VALVE
13 GAS CONTROL VALVE/THERMOSTAT
14* MANIFOLD DOOR GASKET
15 FLANGE
16 DRAIN VALVE
17 ANODE ROD
18* VIEWPORT
19 DOOR SCREW
20* BURNER DOOR ASSEMBLY (NAT. GAS)
21* MANIFOLD COMPONENT BLOCK
22 OUTER DOOR
23 OPTIONAL...