.9°C)* 
(48
(54.4°C)* 
(60°C)*
.9°C)* 
(48
(54.4°C)* 
(60°C)*
*Temperatures shown are approximates and may vary.
Stacking
Stacking occurs when a series of short draws of hot water (3 gallons [11.3 liters] or less) are taken from the water heater tank. This causes increased cycling of the burner
occurrence of igniter failure due to excessive condensate.
Important: A mixing valve (provided) must be installed in the hot water outlet to reduce the risk of scald injury when setting the thermostat in excess of 120°F (48.9°C).
and can result in increased water temperatures at the hot water outlet. A mixing valve must be installed in the hot water supply line to reduce the risk of scald injury.
Water Temperature Regulation
Many home heating systems used with this water heater are designed for temperatures higher than 130°F (54.4°C). Refer to the manufacturer’s instruction manuals supplied with this type of equipment for recommended temperature settings.
Figure 22:
Temperature Dial
°C) .9 
(48
.4C) | |
(54 | ° |
| |
(60°C)
Water temperature over 125°F (51.6°C) can cause severe burns instantly or death from scalds.
Children, disabled and elderly are at highest risk of being scalded.
See instruction manual before setting temperature at water heater.
Feel water before bathing or showering. Temperature limiting valves are available.
The thermostat is adjusted to its lowest temperature setting 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 130°F (54.4°C); however, in some instances, setting the water heater higher than 130°F (54.4°C) can reduce the
Important: Adjusting the thermostat past the 120°F
(48.9°C) setting on the
temperature dial (see figure 22) will increase the risk of scald injury. Hot water can produce first degree burns within:
Table 4 |
| Time for 1st | Time for Permanent Burns |
Water | |||
Temperature | Degree Burn | 2nd & 3rd Degree | |
°F (°C) | (Less Severe Burns) | (Most Severe Burns) | |
110 (43.3) | (normal shower temp.) |
| |
116 (46.7) | (pain threshold) |
| |
116 (46.7) | 35 minutes | 45 minutes | |
122 | (50) | 1 minute | 5 minutes |
131 | (55) | 5 seconds | 25 seconds |
140 | (60) | 2 seconds | 5 seconds |
149 | (65) | 1 second | 2 seconds |
154 | (67.8) | instantaneous | 1 second |
(U.S. Government Memorandum, C.P.S.C., Peter L. Armstrong, Sept. 15,1978)
Emergency Shut Down
Important: If overheating occurs or the gas supply fails to shut off, close the manual gas supply valve. Turn off the electrical supply to the unit and close the cold water supply valve. Do not operate the water heater again until it has been thoroughly checked by an authorized service technician.
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