Ferguson JWSH100250 warranty Installation Instructions, High Limit Switch E.C.O, Circulating Pump

temperature be set for the lowest temperature which satisfies your hot water needs. This will also provide the most energy efficient operation of the water heater and minimize scale formation.

SETTING THE WATER HEATER TEMPERATURE AT 120°F/49°C WILL REDUCE THE RISK OF SCALDS.

Figure 1 shows the approximate time-to-burn relationship for normal adult skin. Short repeated heating cycles caused by small hot water uses can cause temperatures at the point of use to exceed the thermostat setting by up to 20°F/11°C. If you experience this type of use, you should consider using lower temperature settings to reduce scald hazards.

Water	Time to Produce 2nd & 3rd
Temperature	Degree Burns on Adult Skin
180°F / 82°C	Nearly instantaneous
170°F / 77°C	Nearly instantaneous
160°F / 71°C	About 1/2 second
150°F / 66°C	About 1-1/2 seconds
140°F / 60°C	Less than 5 seconds
130°F / 54°C	About 30 seconds
120°F / 49°C	More than 5 minutes
	FIGURE 1.

Valves for reducing point-of-use temperature by mixing cold and hot water are available (see Figure 2). Also available are inexpensive devices that attach to faucets to limit hot water temperatures. Contact a licensed plumber or the local plumbing authority.

FIGURE 2.

HIGH LIMIT SWITCH (E.C.O.)

The top immersion well of the dual bulb controller also contains the high limit (energy cutoff) sensor. The high limit switch interrupts the main burner gas flow should the water temperature reach approximately 202°F/94°C.

Should the high limit switch activate, the control system will automatically reset the unit once the water temperature in the tank falls below 140°F/60°C. If the unit is manually shut down and restarted, as long as the temperature in the tank is lower than 160°F/71°C, the unit will reset and initiate operation.

High limit switch operation is the likely cause when higher than normal water temperatures occur with a recurring need to restart the water heater. This could be due to a malfunctioning thermostat allowing the gas valve to remain open and the burner to continue firing even after water temperature in the tank has already reached the set point. Contact your dealer or servicer if continued high limit switch operation occurs.

DISHWASHING MACHINE REQUIREMENT

All dishwashing machines meeting the National Sanitation Foundation

requirements are designed to operate with water flow pressures between

15 and 25 pounds per square inch (103 Kpa and 173 Kpa). Flow pressures above 25 pounds per square inch (173 Kpa), or below 15 pounds per square inch (103 Kpa), will result in improperly sanitized dishes. Where pressures

are high, a water pressure reducing or flow regulating control valve should

be used in the 180°F (82°C) line to the dishwashing machine, and should be adjusted to deliver water between these limits.

The National Sanitation Foundation also recommends circulation of 180°F (82°C) water. Where this is done, the circulation should be very gentle so that it does not cause any unnecessary turbulence inside the water heater. The circulation should be just enough to provide 180°F (82°C) water at the

point of take-off to the dishwashing machine. Adjust flow by means of the

plug cock in the circulating line. (See installation diagrams.)

CIRCULATING PUMP

A circulating pump is used when a system requires a circulating loop or there is a storage tank used in conjunction with the heater. Refer to the piping diagrams at rear of manual for electrical hookup information and install in accordance with the current edition of the National Electrical Code, NFPA 70 or the Canadian Electrical Code, CSA C22.1.

All bronze circulating pumps are recommended for used with commercial water heaters.

Although circulating pumps are oiled and operated by the manufacturer some circulating pumps must be oiled again before operated. Please refer to manufacturer's instructions.

INSTALLATION INSTRUCTIONS

REQUIRED ABILITY

INSTALLATION OR SERVICE OF THIS WATER HEATER REQUIRES ABILITY EQUIVALENT TO THAT OF A LICENSED TRADESMAN IN THE FIELD INVOLVED. PLUMBING, AIR SUPPLY, VENTING, GAS SUPPLY AND ELECTRICAL WORK ARE REQUIRED.

INSULATION BLANKETS

Insulation blankets available to the general public for external use on gas water heaters are not approved for use on your water heater. The purpose of an insulation blanket is to reduce the standby heat loss encountered with storage tank water heaters. Your water heater meets or exceeds the ASHRAE/IES 90.1 1999 standards with respect to insulation and standby loss requirements, making an insulation blanket unnecessary.

WARNING

Should you choose to apply an insulation blanket to this heater, you should follow these instructions. Failure to follow these instructions can result in

fire, asphyxiation, serious personal injury or death.

•Do not apply insulation to the top, or the upper 15" (38 cm) of the water heater, as this will interfere with safe operation.

•Do not cover the temperature & pressure relief valve.

•Do not cover the instruction manual. Keep it on the side of the water heater or nearby for future reference.

•Do obtain new labels from John Wood for placement on the blanket directly over the existing labels.

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