Lochinvar SNA285-125 Manual Do Utilizador

1.  Read and follow the Operating instructions in FIG.’s 9-2 and 

9-3, pages 49 and 50.

1.  Check for loose connections, blown fuse or service switch 

off.

2.  Is external limit control (if used) open?  Is water temperature 

above 200°F?

3.  Is tank set point set below tank temperature?

4.  Is gas turned on at meter and water heater?

5.  Is incoming gas pressure less than 4 inches w.c.?

If none of the above corrects the problem, refer to the 
Troubleshooting section of this manual.

  Check water piping

1.  Check system piping for leaks. If found, shut down the water 

heater and repair immediately. (See WARNINGS on pages 
47 and 48 (startup) regarding failure to repair leaks.)

2.  Check Delta T.  Ensure Delta T is less than 25°F.

3.  Vent any remaining air from the system using manual vents.  

Air in the system will interfere with circulation and cause 
hot water distribution problems and noise.

  Check vent piping and air piping

1.  Check for gastight seal at every connection, seam of air 

piping, and vent piping.

Venting system must be sealed gastight 
to prevent flue gas spillage and carbon 
monoxide emissions, which will result in 
severe personal injury or death.

  Check gas piping

1.  Check around the water heater for gas odor following 

the procedure on page 39 of this manual (Connecting Gas 
Supply Piping).

If you discover evidence of any gas leak, 
shut down the water heater at once.  Find 
the leak source with a bubble test and repair 
immediately. Do not start the water heater 
again until corrected. Failure to comply 
could result in severe personal injury, death, 
or substantial property damage.

1.  Press the SHUTDOWN button on the display until 

appears in the display window. 

2.  Remove the screws securing the top panel to the unit.  

Remove the panel from the unit to gain access to the flue 
sensor.

3.  Locate the flue sensor in the top of the vent connection.  

Remove the flue sensor and grommet from the unit.  
Note:  Combustion measurements will be made at this 
point.

4.  Press the SHUTDOWN button on the display until 

appears in the display window. 

5.  Locate the pinhole button above the “r” in the Lochinvar 

logo on the display board (FIG. 10-1).  Insert a thin wire 
(such as a paper clip) into the hole and press the button 
once and hold for 5 seconds to place the water heater 
into Service Mode.  In Service Mode the water heater will 
fire at ignition speed and will then modulate up to full 
fire.

6.  Insert the probe from a combustion analyzer into the 

hole left by the removal of the flue temperature sensor.

7.  Once the water heater has modulated up to full fire, 

measure the combustion. The values should be in the 
range listed in Table 9A. The CO levels should be less 
than 150 ppm for a properly installed unit.

 

If the combustion is not within the specified range, 
reference the Troubleshooting section of this manual for 
possible causes and corrective actions.

 WARNING

 WARNING

8.  Once the combustion analysis is complete, press the 
 

SHUTDOWN button on the display board (FIG. 10-1) 

 

to take the water heater out of Service Mode. The 

 

water heater will go to shutdown and the display will 

 show 

.

9.  Replace the flue sensor and grommet into the vent 
 connection.

10.  Replace the top panel on the unit.

11.  Place the Shield water heater back into normal operation.

You must replace the flue sensor to 
prevent flue gas spillage into the room.  
Failure to comply could result in severe 
personal injury, death, or substantial 
property damage.

 WARNING

8.0% - 10%

3.0% - 6.5%

9.0% - 11%

4.1% - 6.9%

       

Installation & Service Manual

TM