copyright 2013-2017 area ii plumbers jatc. all rights reserved. repairs, maintenance, and...

Copyright 2013-2017 Area II Plumbers JATC. All Rights Reserved.

Repairs, Maintenance, and Installation of Electric Residential Water Heaters

8 Hours of Continuing Education

Certified by Oregon Building Codes Division



INSTRUCTIONS FOR USING THIS CONTINUING EDUCATIONLEARNING MATERIAL

This course material is set up in way that maximizes the retention of the information provided. Each page may introduce a new idea, bullet point, etc. from the previous page. Introducing one idea at a time may help organize the information and help you assimilate it in the shorter period of time the continuing education courses take—as compared to full-length training.

When you have read the information offered on one page, simply advance to the next page by clicking the down arrow as seen here.

Before Continuing (IMPORTANT)

Locate the following button at the top of the screen and click it. This will allow you to view each full slide—without having to scroll up and down.

Alternatively, you can press the Page Down button on your keyboard to have the same effect.


COMPONENTS

Objective: After completion of this section, you will be able to identify the components of a residential electric water heater and know what each of their functions are.


Identification of Components


Identifying Components of a Residential Water Heater

Thermostat Protector

Thermostat

Diagram A illustrates where the upper thermostat and the upper thermostat protector are located on the residential water heater.

Diagram A

Diagram B

Diagram B is an up-close viewpoint of what the thermostat and thermostat protector actually look like when installed in the water heater.

Thermostat Mounting

Bracket

Thermostat



Cover Conduit/Ground

Junction Box Cover

Cover Conduit / Ground & Junction Box and Cover

Diagram C illustrates where the cover conduit/ground would be located on an upright electric water heater (and most other types.

On a wall hung electric water heater, the ground conduit/ground and junction box cover may be located on the bottom of (beneath) the water heater.

Diagram C


Elements

Here are two elements as they would commonly be placed in a Double-Element Water Heater.

Upper Element

Lower Element



Diagram D illustrates where the hot water outlet/anode and heat trap insert (outlet) would be located on an upright electric water heater (and most other types.

Diagram E is a close-up view of the hot water heat trap insert. Diagram F is what a hot water anode looks like.

Diagram D

Hot Water Outlet/Anode

Heat Trap Insert (Outlet)

Diagram E

Diagram F



Diagram G: Cold water inlet tube

Diagram H: Heat trap insert (inlet)

Diagram I:

Diagram G

Heat Trap Insert (Inlet)

Cold Water Inlet Dip

Tube

Diagram H

Diagram I

Illustrates dip tube immersed in water.



Diagram I.1

Sacrificial Anode

Diagram I.1 illustrates where the sacrificial anode might be located on a typical water heater. Not all water heaters have a sacrificial anode.



Diagram J illustrates one of the places a T&P Relief Valve may be installed on an upright residential water heater. In addition, an alternative place to install the relief valve is noted in red.

Diagram K illustrates what a T&P Relief Valve looks like.

Diagram J

T&P Relief Valve

Diagram K

Alternative Placement for the T&P Relief

Valve



Diagram K.1 illustrates an overflow pipe connected to a temperature / pressure relief valve.

Diagram K1

Overflow Pipe



Diagram K.2 illustrates the cold water shut-off valve, otherwise known as a water supply valve.

Diagram K2

Shut-Off Gate Valve (Water Supply Valve)

This shut-off valve is a screw-to-close, screw to open version.

Diagram K3

Diagram K.3 illustrates the ball valve version of the cold water shut-off valve, otherwise known as a water supply valve.

This shut-off valve utilizes a ball to block water flow.

Shut-Off Ball Valve (Water Supply Valve)



Drain Valve

Diagram K4


Function of Components


Thermostat Components

General DescriptionOf Thermostat


Understanding Functions of Components


Understanding Functions of ComponentsThermostat


General Introduction





Definition: A device that automatically regulates temperature, or that activates a device when the temperature reaches a certain point.




In an electric water heater, the function of the thermostat is to use energy (electricity) to heat the water in the tank. The voltage varies, depending on the brand, size, and type of water heater. The required voltage will be found on the water heater.





The thermostat monitors the temperature and averts an explosion by shutting off it’s energy source if the temperature exceeds safe temperatures.


Diagram A

Diagram B



Thermostat

Thermostat Mounting Bracket




More than one thermostat may be found on a water heater, which changes the way a single thermostat may function. The types of water heater systems that are most typical for residential electric water heaters are:



Thermostat

Diagram A

Diagram B










Thermostat

Diagram A

Diagram B




•Single Element (single thermostat)







Thermostat

Diagram A

Diagram B





•Double Element, Non-Simultaneous, Single Phase (two thermostats-working at opposite times)







Thermostat

Diagram A

Diagram B






•Double Element, Simultaneous, Single Phase, 4 Wire Service (two thermostats-working at the same time)







Thermostat

Diagram A

Diagram B






•Double Element, Simultaneous, Single Phase, 4 Wire Service (two thermostats-working at the same time)

•Double Element, Non-Simultaneously, Single Phase, Off Peak (two thermostats-working at opposite times)



Introduction to a Two Element System and the Electrical Diagram


Understanding Functions of ComponentsThermostat (cont.)

Introduction to a Two-Element System and the Electrical Diagram




Upper Thermostat




Upper Element




Lower Thermostat




Lower Element



Single Element (one thermostat)



Single Element (single thermostat)




Electricity (line voltage) is applied across terminal L1 and terminal L3 of the thermostat. The ECO (Energy Cut Off) is closed, so there is voltage at terminal L4 and to one side of the element.

DIAGRAM L





DIAGRAM L

When the tank is cold, the thermostat will be closed at terminal T2. When this happens, the circuit will be completed and will allow the current to flow through the element.

When water temperature is cold

DIAGRAM M




Thermostat (cont.)

When the tank is cold, the thermostat will be closed at terminal T2. When this happens, the circuit will be completed and will allow the current to flow through the element.



DIAGRAM L

DIAGRAM M

When the water temperature is within the acceptable heated range, the flow through the element will be interrupted. This happens because terminal T2 opens, preventing the current from flowing. As a result, the system will be in stand-by mode.

When water is heated

DIAGRAM N



Double Element, Non-Simultaneous, Single Phase (two thermostats / two elements)




Electricity (line voltage) is applied across terminal L1 and terminal L3 of the thermostat. The ECO (Energy Cut Off) is closed, so there is voltage at terminal L4 and to one side of the upper and lower elements.




Both thermostats will be closed at terminal T2 and terminal 2. The circuit will be complete through the upper thermostat only-allowing the current to flow through the upper element.


Thermostat (cont.)







Thermostat (cont.)


The upper thermostat will be satisfied, terminal T2 will be open, there will be no current to the upper element, and terminal T4 will be closed—allowing flow through the lower thermostat and the lower element.

When water in the tophalf is optimally heated








Thermostat (cont.)


Because the lower thermostat is satisfied, terminal 2 will open and the lower element will no longer heat – placing the system in stand-by mode.

When water in the bottom half is optimally heated








Because the lower thermostat is satisfied, terminal 2 will open and the lower element will no longer heat – placing the system in stand-by mode.


Thermostat (cont.)


When the tank is cold, and in times of high demand, the upper thermostat will engage before the lower thermostat has reached it’s optimal temperature. Terminal T4 will open and terminal T2 will close. As a result, only the upper element will heat.

On and Off Cycling



Double Element, Simultaneous, Single Phase, 4 Wire Service

(two thermostats / two elements)



Double Element, Simultaneous, Single Phase, 4 Wire Service (two thermostats / two elements)

Thermostat (cont.)




Thermostat (cont.)

Electricity (line voltage) for circuit one is applied across terminal L1 and terminal L3 of the lower thermostat. Voltage for circuit two is applied across terminal L1 and terminal L3 of the upper thermostat. The ECO (Energy Cut Off) in both thermostats is closed, so there is voltage at terminal L4 of each thermostat and to one side of the upper and lower elements.

DIAGRAM T





Thermostat (cont.)

DIAGRAM T

Both thermostats will be closed at terminal T2. The circuit will be complete through both thermostats-allowing the current to flow through both elements.


DIAGRAM U

DIAGRAM U





Both thermostats will be closed at terminal T2. The circuit will be complete through both thermostats-allowing the current to flow through both elements.

Thermostat (cont.)


DIAGRAM T DIAGRAM U

Once either thermostat is satisfied, terminal T2 will be open and there will be no current to the corresponding element. Once both thermostats are satisfied, the system will be in stand-by mode. Thermostats will operate independent of one another.

When water in either half is optimally heated

DIAGRAM V



Double Element, Non-Simultaneous, Single Phase, Off Peak

(two thermostats / two elements)



Double Element, Non-Simultaneous, Single Phase, Off Peak (two thermostats / two elements)

Thermostat (cont.)




Thermostat (cont.)

Electricity (line voltage) is applied across terminal L1 and terminal L3 of the upper thermostat. Line voltage from off peak meter is supplied to terminal L1 of lower thermostat. The ECO (Energy Cut Off) in the upper thermostat is closed, so there is voltage at terminal L4 of the upper thermostat and to one side of the upper element.




Thermostat (cont.)


Both thermostats will be closed at terminal T2. The circuit will be complete through the upper thermostat only - allowing the current to flow through the upper element.





Thermostat (cont.)


Both thermostats will be closed at terminal T2. The circuit will be complete through the upper thermostat only-allowing the current to flow through the upper element.


The upper thermostat will be satisfied, terminal T2 will be open, there will be no current to the upper element, and terminal T4 will be closed—allowing flow through one side of the lower thermostat. With the circuit through the lower thermostat and off peak meter now complete, there will be flow through the lower element.





Thermostat (cont.)


Both thermostats will be closed at terminal T2. The circuit will be complete through the upper thermostat only -allowing the current to flow through the upper element.




Because the lower thermostat is satisfied, terminal T2 will open and the lower element will no longer heat – placing the system in stand-by mode.





Thermostat (cont.)


Both thermostats will be closed at terminal T2. The circuit will be complete through the upper thermostat only -allowing the current to flow through the upper element.




Because the lower thermostat is satisfied, terminal T2 will open and the lower element will no longer heat – placing the system in stand-by mode.


The off peak meter will interrupt power to terminal L1 of the lower thermostat. Only the top thermostat / element combination is allowed to operate. Note: the local utility will determine high demand times.

Peak Power Demands


Electrical Components



Including knockout hole, flexible conduit, conduit connector, and grounding wire

Electrical Cover Plate / Junction Box Cover

The electrical cover plate serves as both the cover and as the ground.





The function of the flexible conduit is to hold and protect the electrical wiring between the electrical access point and incoming external electrical source.





The conduit connector is thread into the knockout hole. The conduit will be fitted into the conduit connector.





If there is no established hole (i.e., on the electrical cover plate), there should be a knockout hole available near the cover plate. Once the hole cover has been removed, the wires will eventually feed into this hole to provide the electrical source to the water heater.


Remaining Components


Understanding Functions of Remaining ComponentsHeating Elements



This is a screw in heating element for a residential water heater.




Electricity is supplied to the heating element when the thermostat registers a pre-determined drop in water temperature.





Electricity is supplied to the heating element when the thermostat registers a pre-determined drop in water temperature. The element(s) then heat the water until it reaches a pre-determined temperature. The thermostat will then prevent the electricity from reaching the element—until the water has become too cool again—when the cycle will repeat.





The screw in heating element is

A simple U-shape element. The ad-vantage of this element is cost-effectiveness.


connected to the water heaterwith a large thread and nut. The

Element pictured (lower left), is



Another heating elements design is the folded back version. Pictured below (side right). The advantage of this design is its ability to prevent mineral buildup. The cost is a disadvantage when compared to the more widely used, simple, U-shape element.



The screw in heating element is

A simple U-shape element. The ad-vantage of this element is cost-effectiveness.


connected to the water heaterwith a large thread and nut. The

Element pictured (lower left), is


Understanding Functions of Remaining ComponentsHot Water Outlet Components



Hot Water Outlet (also known as the heat-out pipe)




The hot water outlet carries the heated water to the household appliances. Because of the way hot water raises above cold water, the water that exits through the hot water outlet will be the hottest water available in the tank.







Heat Trap InsertHot Water

Outlet/Anode

Heat Trap Insert

(Outlet)




The heat trap insert prevents excessive heat loss through the outlet piping. A good heat trap insert would reduce standby heat loss up to 40% or more.



Outlet/Anode

Heat Trap Insert

(Outlet)


Understanding Functions of Remaining Components

The older version of heat trap inserts utilize a ball, which is prone to making noise. The newer versions are quieter.

Hot Water Outlet Components


The heat trap insert prevents excessive heat loss through the outlet piping. A good heat trap insert would reduce standby heat loss up to 40% or more.



Outlet/Anode

Heat Trap Insert

(Outlet)


Understanding Functions of Remaining ComponentsCold Water Inlet (Dip Tube) Components



Cold Water Inlet (also known as the Dip Tube)


Tube



The cold water inlet draws water into the water heater; Once in the tank, it travels to the bottom of the tank to be heated.


Tube






Tube



Heat Trap Inserts





Tube



The heat trap inserts prevent excessive heat loss through the outlet piping. A good set of heat trap inserts would reduce standby heat loss up to 40% or more.

Heat Trap Inserts





Tube



The older version of heat trap inserts utilize a ball, which is prone to making noise. The newer versions are quieter.

The heat trap inserts prevent excessive heat loss through the outlet piping. A good set of heat trap inserts would reduce standby heat loss up to 40% or more.

Heat Trap Inserts


Understanding Functions of Remaining ComponentsSacrificial Anode



Sacrificial Anode

The sacrificial anode rod draws to itself the harmful conductivity caused by oxygen, magnesium, fluoride, chlorine and suspended particles within the tank. In essence, it sacrifices itself by drawing this conductivity and allowing itself to be the focus of corrosion before the tank becomes deteriorated.

Sacrificial Anode



Sacrificial Anode


Sacrificial Anode

Not all water heaters have a sacrificial anode rod. Once the anode rod becomes corroded, it can cause a bad odor. The odor has been described as similar to rotten eggs.



Sacrificial Anode


Sacrificial Anode

Not all water heaters have a sacrificial anode rod. Once the anode rod becomes corroded, it can cause a bad odor. The odor has been described as similar to rotten eggs.

However, this odor can also be caused by having an anode made of the wrong type of material. Sometimes, switching from one type (magnesium, zinc aluminum) to another can solve the problem.



T&P Relief Valve

Alternative Placement for the T&P Relief Valve

Temperature & Pressure Relief Valve



The T&P Relief Valve (two devices in one) protects the water heater from damage and explosion by preventing high water temperatures and high pressure build up.

T&P Relief Valve






T&P Relief Valve



Not all water heaters have the combined T&P Relief Valve—it’s important to note that Oregon Law requires either:




T&P Relief Valve




A Temperature Relief Valve AND a Pressure Relief Valve

ORA T&P Relief Valve




T&P Relief Valve





ORA T&P Relief ValveThe T&P Relief Valve responds to

excessive pressure by opening at the set pressure point of the valve.



T&P Relief Valve



The T&P Relief Valve responds to excessive pressure by opening at the set pressure point of the valve.

When it senses a build up of pressure, it opens to relieve the thermal expansion and returns the pressure back to normal.




ORA T&P Relief Valve




T&P Relief Valve





ORA T&P Relief ValveThe T&P Relief Valve responds to

excessive pressure by opening at the set pressure point of the valve.

When it senses a build up of pressure, it opens to relieve the thermal expansion and returns the pressure back to normal.

When the temperature of the water reaches 210 degrees, the T&P Relief Valve discharges the overheated water, allowing the cooler water to enter the tank and bring temperatures back to normal.



Overflow Pipe

The overflow pipe, connected to the temperature / pressure relief valve, directs leaking water away from the tank and to the floor.

Diagram K1

Overflow Pipe

Overflow Pipe


Understanding Functions of Remaining ComponentsShut-Off Valve (Water Supply Valve)



Whether the cold water shut-off valve, otherwise known as a water supply valve, is the gate or ball style—its function is to stop the flow of water into the tank. The ball valve is the

more widely used of the two.

Shut-OffBall

Valve

Shut-Off Valve (Water Supply Valve)

Shut-OffGate

Valve


Understanding Functions of Remaining ComponentsDrain Valve



Drain Valve

The drain valve is available in several different designs. Regardless of the design, its purpose is the same.



Drain Valve

The drain valve is available in several different designs. Regardless of the design, its purpose is the same.

The drain valve will be opened to release water from the tank and closed to prevent water from exiting through the bottom of the tank.


Understanding Functions of Remaining ComponentsEarthquake Ties



In seismic design categories C, D, E, and F, water heaters shall be anchored or strapped to resist horizontal displacement due to earthquake motion.

Return to Installing the Residential Hot Water Heater




Exception: Water heaters in residential structures in seismic design category C

are not required to be strapped or anchored to resist horizontal

displacement due to earthquake motion.




EarthquakeTies








EarthquakeTies


Strapping shall be at points within the upper one-third (1/3) and lower one-third (1/3) of its vertical dimensions.







EarthquakeTies


At the lower point, a distance of not less than four (4) inches (102 mm) shall be maintained above the controls with the strapping.

Strapping shall be at points within the upper one-third (1/3) and lower one-third (1/3) of its vertical dimensions.





copyright 2013-2017 area ii plumbers jatc. all rights reserved. repairs, maintenance, and...

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