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HEATING SYSTEMS

HOT WATER SUPPLY
MIXING VALVES
NO HEAT - BOILER / FURNACE DIAGNOSIS
PLASTIC HEATER VENT
PLUMBING TOPICS

SEWER GAS ODORS
WATER HEATERS
AGE of WATER HEATERS
ALTERNATIVE HOT WATER SOURCES
  Electric Shower Heaters
  High Efficiency Water Heaters
  Indirect-fired Water Heaters
  Instantaneous Water Heaters
  Multiple water heaters in parallel
  Multiple water heaters in series
  Range Boiler Water Heaters
  Side Arm Coil Water Heaters
  Solar Water Heaters
  Tankless Coil for Hot Water
HEATING SYSTEMS
AIRBOUND HEAT SYSTEM REPAIRS
ANODES & DIP TUBES on WATER HEATERS
ANTI SCALD VALVES
CHIMNEY INSPECTION DIAGNOSIS REPAIR
CLOGGED PIPING & Hot Water Flow
DRAIN a WATER HEATER TANK
ELECTRIC WATER HEATERS
  Identify Electric Water Heater Parts
  Electric Water Heater Checklist
  Electric Water Heater Controls List
  Water Heater Anode & Dip Tube Check
  Hot Water Temperature & Pressure Valve
  Electric Water Heater Repair Guide
  Electric Water Heater: No Hot Water
  Electric Water Heater Reset & Temp Set
  Test Electric Water Heater High Temp Cutoff
  Test Electric Water Heater Elements
  Replace Electric Water Heater Element
GAS FIRED WATER HEATERS
HOT WATER IMPROVEMENTS
HOT WATER QUANTITY IMPROVEMENT
  Alternative Hot Water Sources & Methods
  Anti-Scald Valves & Hot Water Quantity
  CLOGGED PIPING & Hot Water Flow
  Extra Tanks to Increase Hot Water
  Insulate Hot Water Piping
  Insulate Hot Water Tank?
  Larger Diameter Water Supply Piping
  Tankless Coil Hot Water Increase
  Temperature of Hot Water is Too Low
INDIRECT FIRED WATER HEATERS
ODORS IN WATER
OIL FIRED WATER HEATERS
MIXING VALVES
RANGE BOILERS
RELIEF VALVES - TP Valves on Boilers
Relief Valves - Water Heaters
SEWER GAS ODORS
SEWER LINE REPLACEMENT
SOLAR HOT WATER HEATERS
TANKLESS COILS
Water Heater Noises
WATER HEATER PROPERTIES
  Electric, Gas, Oil Water Heater Efficiency
  Water Heater Life Expectancy Comparisons
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  Water Heater Purchase & Maintenance Costs
  Water Heater Water Quantity Comparisons
  Water Heater Recovery Speed Comparisons
  Water Heater Safety Comparisons
Water Heater Scale - De-Liming Procedures
WATER SOFTENERS

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Schematic of a sacrificial anode on a hot water tank (C) Carson DunlopList of Key Controls & Parts for Electric Hot Water Heaters - Inspection, Diagnosis, & Repair
InspectAPedia®  -    

  • Electric Water heaters: how to inspect, test, adjust, repair a water heater
  • How to find & identify the parts & controls on an electric water heater
  • How to test and repair an electric hot water heater
  • How to replace the heating element on an electric water heater
  • Guide to inspection of electric water heaters
  • No Hot water? how to get more hot water flow, quantity, performance from your water heater
Our site offers impartial, unbiased advice without conflicts of interest. We will block advertisements which we discover or readers inform us are associated with bad business practices, false-advertising, or junk science. Our contact info is at InspectAPedia.com/appointment.htm.

Here we describe the key controls and parts in electric hot water heater operation. Additional "hidden" controls on an electric hot water heater include its thermostat, high temperature cutout. We address these under-the-covers water heater controls beginning at Electric Water Heater Repair Guide. The articles at this website will answer most questions about electrical water heaters as well as many other building plumbing system inspection or defect topics. Page top sketch is courtesy Carson Dunlop. Reproduction of this web page electronically at other websites is prohibited.

© Copyright 2009 Daniel Friedman, All Rights Reserved. Information Accuracy & Bias Pledge is at below-left. Use links at the left of each page to navigate this document or to view other topics at this website. Green links show where you are in our document or website.

But watch out: sometimes an electric water heater is installed as an additional or backup hot water source, so you'll also want to see if you have other hot water heating equipment installed, such as a Tankless Coil for Hot Water.

List of Electric Water Heater Controls & Operation

Sketch of electric water heater element operating details (C) Carson Dunlop

 

Carson Dunlop's sketch describes the sequence of operation that turns on the electric water heater's heating elements. If one of these heating elements has failed, the quantity or the temperature of hot water provided will be substantially reduced.

  • A pressure/temperature relief valve - See Relief Valves - TP Valves
  • Cold water in and hot water out supply piping
  • A cold water inlet shutoff valve
  • A water tank drain valve
  • A thermostat to set water temperature, located at one (or both) of the electric heating elements - Refer to our diagnosis of a failed electric water heater element at Temperature of Hot Water is Too Low.
  • An electrical switch to turn power off to the water heater;

Check the Sacrificial Anode & Dip Tube of Your Water Heater Tank

Schematic of a sacrificial anode on a hot water tank (C) Carson Dunlop

The dip tube on many water heaters functions as a sacrificial anode, as we show here. By constructing the dip tube of a metal which is more readily corroded than the steel of a steel hot water tank, the anode protects the hot water tank from early failure due to corrosion. Here Carson Dunlop's sketch shows the location of the sacrificial anode on an electric water heater.

If your water supply happens to be highly conductive or corrosive (see WATER TESTING GUIDE) then the dip tub/sacrificial anode in the water tank may indeed corrode away until it leaks (dropping the hot water temperature) or disappears entirely.

If your hot water smells like rotten eggs, you should definitely check the condition of the sacrificial anode on the hot water heater, no matter what kind of water tank you've got installed.

For details of how to inspect or replace the sacrificial anode or dip-tube on a water heater, please see Water Heater Anodes & Dip Tubes

Check the Hot Water Tank Temperature and Pressure Safety Relief Valve

Water heater temperature pressure relief valve (C) Daniel Friedman

Our photo (left) shows an unsafe extension tube on a water heater tank - the diameter of the extension(1/2") is less than the valve opening diameter (3/4").

This restriction could prevent proper valve operation should unsafe over pressure or over-temperature conditions occur at the water heater.

For details about water heater relief valves, please see Testing the Water Heater Temperature Pressure Relief Valve

Electric Water Heater Controls Behind the Removable Cover Panels on the Heater

Water  heater thermostast and reset switch (C) Daniel Friedman

Additional "hidden" controls on an electric hot water heater include its thermostat, high temperature cutout.

We address these under-the-covers water heater controls next, beginning at Electric Water Heater Repair Guide.

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Use links just below or at the left of each page to navigate this document or to view other topics at this website. Green links show where you are in our document or website.

WATER HEATERS
AGE of WATER HEATERS
ALTERNATIVE HOT WATER SOURCES
  Electric Shower Heaters
  High Efficiency Water Heaters
  Indirect-fired Water Heaters
  Instantaneous Water Heaters
  Multiple water heaters in parallel
  Multiple water heaters in series
  Range Boiler Water Heaters
  Side Arm Coil Water Heaters
  Solar Water Heaters
  Tankless Coil for Hot Water
  Tankless Water Heaters
ANODES & DIP TUBES on WATER HEATERS
ANTI SCALD VALVES
ELECTRIC WATER HEATERS
  Identify Electric Water Heater Parts
  Electric Water Heater Checklist
  Electric Water Heater Controls List
  Water Heater Anode & Dip Tube Check
  Hot Water Temperature & Pressure Valve
  Electric Water Heater Repair Guide
  Electric Water Heater: No Hot Water
  Electric Water Heater Reset & Temp Set
  Test Electric Water Heater High Temp Cutoff
  Test Electric Water Heater Elements
  Replace Electric Water Heater Element
  Drain a Hot Water Heater Tank
HOT WATER IMPROVEMENTS
HOT WATER QUANTITY IMPROVEMENT
INDIRECT FIRED WATER HEATERS
ODORS IN WATER
OIL FIRED WATER HEATERS
MIXING VALVES
RANGE BOILERS
RELIEF VALVES - TP Valves on Boilers
Relief Valves - Water Heaters
SOLAR HOT WATER HEATERS
TANKLESS COILS
Water Heater Noises
WATER HEATER PROPERTIES
  Electric, Gas, Oil Water Heater Efficiency
  Water Heater Life Expectancy Comparisons
  Water Heater Operating Cost Comparisons
  Water Heater Purchase & Maintenance Costs
  Water Heater Water Quantity Comparisons
  Water Heater Recovery Speed Comparisons
  Water Heater Safety Comparisons
Water Heater Scale - De-Liming Procedures
WATER SOFTENERS

  • Thanks to Alan Carson and Bob Dunlop, Carson Dunlop, Associates, Toronto, for permission to use illustrations from their publication, The Illustrated Home which illustrates construction details and building components. Carson Dunlop provides home inspection education, publications, report writing materials, and home inspection services. Alan Carson is a past president of ASHI, the American Society of Home Inspectors.

Books & Articles on Building & Environmental Inspection, Testing, Diagnosis, & Repair

  • Our recommended books about building design, inspection, and repair, and about indoor environment testing, diagnosis, and cleanup are at the InspectAPedia Bookstore.
  • ...
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05/28/2009 - 06/27/1995 - InspectAPedia.com/plumbing/Electric_Hot_Water2.htm - © 2009 - 1988 Copyright Daniel Friedman All Rights Reserved - InspectAPedia® is a Registered U.S. Trademark