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RESIDENTIAL ELECTRIC AND LIGHT DUTY
COMMERCIAL ELECTRIC WATER HEATERS
SERVICE
MANUAL
Troubleshooting Guide
and Instructions for Service
(To be performed ONLY by
qualified service providers)
Models Covered
by This Manual:
Residential Energy Saver:
M1& M2(HE) UprightModels.
M1& M2 Lowboy Models.
M1& M2 UtilityModels.
M1& M2 Wall HungModels.
Light DutyEnergy Saver:
LD Upright Models.
LD Utility Models.
LD Lowboy.
LD WallHung.
Dairy Barn Deluxe Energy Saver:
DB Models.
Photo is of
M-2-50T6DS
Manual
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Residential and Light Duty Commercial Electric Water Heaters Table of Contents Page Service Procedure Introduction ………………………………………………………………………. 2 Tools……………………………………………………………………………… 2 General Information ……………………………………………………………… 3 - - - Sequence of Operation …………………………………………………………… 6 - - - Single Element Operation ……………………………………................... 6 - - - Double Element, Non-Simultaneous, Single Phase………………………. 7 - - - Double Element, Simultaneous, Single Phase, 4 wire Service …............... 8
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GENERAL INFORMATION Commonly Used Formulas Amps = Watts (for single phase units) Example 4500W/240V = 18.75A Volts Amps = Watts (for balanced 3 phase units) Example 4500W/240V x 1.732 = 10.82A Volts x 1.732 Watts = Amps x Volts Example 18.75A x 240V = 4500W 2 2 Ohms = Volts Example (240V) / 4500W = 12.8 Ohms Watts Common Service Wire Configurations 120 VOLT 240 VOLT WHITE Grounded BLACK GREEN BLACK GREEN RED (Neutral) Grounding Ungrounded Grounding Ungrounded Ungrounded 120 0 240 12
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GENERAL INFORMATION Wattage Limitations at Various Voltages Residential Electric Upright M1 & M2 Series (Non-Simultaneous operation) Residential High Efficiency Upright M2HE Series (Non-Simultaneous operation) Residential Electric Lowboy M1 & M2 Series (Non-Simultaneous Operation) Dairy Barn Deluxe DB Series (Non-Simultaneous Operation) Voltage Maximum Element Wattage Upper/Lower 3,000/3,000 120 3,000 6,000 6,000/6,000 208, 240 277, 480 6,000 6,000/6,000 Residential Electric Upright M1 & M2 Seri
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GENERAL INFORMATION Surface Mounted Thermostats Surface mounted thermostats are mounted into a bracket which holds the thermostat against the side of the tank. Surface mounted thermostats respond to tank surface temperatures to sense a call for heat, set point temperature settings and high limit (ECO) activation. It is import that the entire back surface of the thermostat is in full contact or flush with the tank. Improperly mounted thermostat will lead to improper heater operation. Manual ECO (
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SEQUENCE OF OPERATION Residential and light duty commercial electric water heaters are designed to operate using several different operating modes. The common modes and sequence of operation are as follows: 1. Single Element Operation. 2. Double Element Non-Simultaneous Operation (single phase). 3. Double Element Non-Simultaneous Operation (3 phase). 4. Double Element Simultaneous Operation (single phase). 5. Double Element Simultaneous Operation (3 phase). Sequence of Operation- Single Element
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SEQUENCE OF OPERATION Non-Simultaneous and Simultaneous Operation Double element electric water heaters are designed to operate in a Non-Simultaneous or Simultaneous mode. Non-Simultaneous Mode: Allows only one heating element to operate at a time. For example, when the tank is cold, the upper element is energized first, heating the top of the tank. Only when the upper thermostat is satisfied, the upper element is de-energized and power is directed to the lower thermostat, energizing the lower e
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SEQUENCE OF OPERATION A 4 wire, double element heater wired for simultaneous operation is essentially two single element systems operating independently. The heaters are wired internally with two independent circuits, one circuit for each thermostat/element combination. When installed using a two wire service, the blue and red (or white) wires will be connected together, likewise black and yellow wires will be connected together. Sequence of Operation- Double Element, Simultaneous Operation, Sin
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SEQUENCE OF OPERATION Sequence of Operation- Double Element, Non-Simultaneous Operation, 3 Phase. 1 2 1 Line voltage is applied across terminals L1 ECO Thermostat closed Closed & L3 of upper thermostat. Likewise, Line at terminal T2 voltage is applied to terminal L3 of lower thermostat. ECO in both upper & lower thermostat is closed, so there is voltage at terminal L4 of both thermostats and to one side of both upper & lower elements. 2 Tank is cold therefore both thermostats ECO Closed Thermost
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SEQUENCE OF OPERATION Sequence of Operation- Double Element, Simultaneous Operation, 3 Phase. 1 1 2 Line voltage is applied across terminals L1 & L3 of upper thermostat. Line voltage also extends to terminal L1 of lower thermostat. ECO Also, line voltage is applied to terminal L3 Closed Thermostat closed at terminal T2 of lower thermostat. ECO in both upper & lower thermostat is closed, so there is voltage at terminal L4 of both thermostats and to one side of both upper & lower elements. 2 Tank
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SEQUENCE OF OPERATION Some electric utility companies will offer discounts for using electricity during “Off Peak” Times of the day. The system allows the use of an “Off Peak” meter, which interrupts power to the lower element during high power demand periods. Sequence of Operation- Double Element, Non-Simultaneous Operation, Single Phase, Off Peak. 1 Line voltage is applied across terminals L1 & L3 of the upper thermostat. Line voltage from off peak meter is supplied to terminal L1 of lower the
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TROUBLESHOOTING Most common cause for improper electric water heater operation can be linked to heating element failure. When troubleshooting an electric water heater with the incidence of “No Hot Water” or “Insufficient Amount of Hot Water” Its always a good idea to check the heating elements first following the procedure on page 15. Common Heating Element Failures Are: 1. Dry Firing. Element may be partially submerged in water or most likely, completely exposed with no water in tank. In some
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TROUBLESHOOTING Quick Step Plan to Hot Water WARNING High voltage exposure. Use caution when 1. TURN OFF power to water heater and check all wire making voltage checks to avoid personal connections to insure they are tight and corrosion free. injury. 2. Turn power “ON” and determine that service voltage is present, and the high limit (ECO) has not actuated (see procedure on page 14). 3. Check for inoperative heating element (see procedure on page 15). 4. Check for proper thermostat operation
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SERVICE PROCEDURE RE-I Line Voltage & High Limit (ECO) Testing Line Voltage Testing WARNING High voltage exposure. Use caution when making voltage checks to avoid personal injury. 1. Turn “OFF” power to water heater. 2. Remove access cover(s) from front of water heater. Remove insulation and plastic cover from thermostat. ECO reset button 3. Set multi-meter to volts AC. 4. Turn power “ON” to water heater. 5. Check voltage across terminals L1 & L3 of upper thermostat (see illustration 2). A) R
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SERVICE PROCEDURE RE-II Heating Element Testing Testing For Open Or Burned Out Element. WARNING High voltage exposure. Be sure power is turned OFF to water heater prior to performing this Step 1. TURN OFF POWER TO WATER HEATER. procedure. Step 2. Remove access cover(s) from front of water heater. Remove insulation and plastic cover from thermostat. Step 3. Disconnect wires from heating element. Step 4. Set multi-meter to “ohms” setting. Step 5. Touch probes of multi-meter to screw terminals of h
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SERVICE PROCEDURE RE-III Residential Thermostat Testing WARNING Single Element Operation or High voltage exposure. Use caution to avoid Double Element, 4 Wire, Simultaneous, Single Phase Operation. personal injury during this procedure. Water In Tank Is Cold With Power ON. 1. This procedure assumes line voltage, ECO and elements are in working order. 2. Turn power “ON” to water heater. 3. Set multi-meter to “Volts AC”. 4. Check across terminals L4 and T2 of thermostat (see illustration 6). A
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SERVICE PROCEDURE RE-III Residential Thermostat Testing WARNING Double Element, Non-Simultaneous, Single Phase High voltage exposure. Use caution to avoid Operation. personal injury during this procedure. Water In Tank Is Cold With Power ON. 1. This procedure assumes line voltage, ECO and elements are in working order. 2. Turn power “ON” to water heater. 3. Set multi-meter to “Volts AC”. 4. Check across terminals L4 and T2 of upper thermostat (see illustration 8). A) Rated voltage NOT presen
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SERVICE PROCEDURE RE-III Residential Thermostat Testing WARNING Double Element, Non-Simultaneous, Single Phase High voltage exposure. Use caution to avoid Operation (continued). personal injury during this procedure. Not Enough Hot Water (continued). 7. Check voltage across terminal L4 of upper thermostat and terminal 1 of lower thermostat (see illustration 11). A) Rated voltage NOT present, - check wire connection between thermostats. B) Rated voltage IS present, okay, go to step 8. 8
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SERVICE PROCEDURE RE-III Residential Thermostat Testing WARNING Double Element, Non-Simultaneous, Three Phase High voltage exposure. Use caution to avoid Operation. personal injury during this procedure. Water In Tank Is Cold With Power ON. 1. This procedure assumes line voltage, ECO and elements are in working order. 2. Turn power “ON” to water heater. 3. Set multi-meter to “Volts AC”. 4. Check across terminals L4 and T2 of upper thermostat (see illustration 13). A) Rated voltage NOT presen
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SERVICE PROCEDURE RE-III Residential Thermostat Testing Double Element, Non-Simultaneous, WARNING Three Phase Operation (continued). High voltage exposure. Use caution to avoid personal injury during this procedure. Tank Does Not Deliver Enough Hot Water (continued) 7. Check voltage across terminal L1 & L3 of lower thermostat (see illustration 16). A) Rated voltage NOT present, check wire connection between thermostats. B) Rated voltage is present, okay, go to step 8. 8. Adjust lower thermostat
