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WATER HEATERS

AGE of WATER HEATERS
AIRBOUND HEAT SYSTEM REPAIRS
ALTERNATIVE HOT WATER SOURCES
ANODES & DIP TUBES on WATER HEATERS
ANTIFREEZE for BOILERS
ANTI SCALD VALVES
APPLIANCE EFFICIENCY RATINGS
AQUASTAT CONTROL Functions

BACKDRAFTING HEATING EQUIPMENT
BACKFLOW PREVENTER, HEATER WATER FEEDER
BLEVE EXPLOSIONS
BOILERS, HEATING

CARBON MONOXIDE - CO
CHECK VALVES, WATER SUPPLY
CHEMICAL CONTAMINANTS in WATER
CHIMNEY INSPECTION DIAGNOSIS REPAIR
CLOGGED SUPPLY PIPING

DEBRIS in WATER SUPPLY, Water Heater
DRAIN a WATER HEATER TANK

ELECTRIC WATER HEATERS

FLOODED HEATING EQUIPMENT REPAIR
FLOODED WATER HEATER REPAIR

GALVANIC SCALE & METAL CORROSION
GAS BURNER Flame & Noise Defects
GAS FIRED WATER HEATERS
GAS PIPING, VALVES, CONTROLS

HOT WATER SUPPLY

INDIRECT FIRED WATER HEATERS

MANUALS & PARTS GUIDES - HVAC
MIXING / ANTI-SCALD VALVES

NO HEAT - NO HOT WATER: HEATER DIAGNOSIS
NOISE / SOUND DIAGNOSIS & CURE
NOISE CONTROL for HEATING SYSTEMS
NOISE, PLUMBING CHECKLIST
NOISE, WATER HEATER

ODORS GASES SMELLS, DIAGNOSIS & CURE
ODORS IN WATER

PIPING IN buildings, Clogs Leaks Types
PLASTIC HEATER VENT
PLUMBING FIXTURES, KITCHEN, BATH

RANGE BOILERS
RELIEF VALVE LEAKS
RELIEF VALVES - Water Heaters

SCALE REMOVAL, WATER HEATERS
SEWER GAS ODORS
SOLAR HOT WATER HEATERS
SOOT on OIL FIRED HEATING EQUIPMENT
SPILL SWITCHES - Flue Gas Detection

TANKLESS COILS
TANKLESS WATER HEATERS
Temperature Pressure Relief Valves - Water Heaters
THERMOSTATS, WATER HEATER
TIMERS for ELECTRIC WATER HEATERS

VALVES, PLUMBING

WATER CONTAMINANT LEVELS
WATER HAMMER NOISE DIAGNOSE & CURE
WATER HEATERS
WATER ODORS, CAUSE CURE
WATER PIPES, Clogs Leaks Types
WATER PRESSURE & FLOW MEASUREMENT
WATER PRESSURE LOSS DIAGNOSIS & REPAIR
WATER QUANTITY IMPROVEMENT
WATER SOFTENERS & CONDITIONERS
WINTERIZE A BUILDING


More Information

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
     

  • Electric Water heater controls & parts: how to find and use or repair parts & controls on water heaters: start by knowing what you're looking at
    • How to find & identify the parts & controls on an electric water heater
    • No Hot water? how to get more hot water flow, quantity, performance from your water heater
  • ELECTRIC WATER HEATERS
    • Electric, Gas, Oil Water Heater Efficiency
    • ELECTRIC SHOWER HEATERS
    • Electric Water Heater Checklist
    • ELECTRIC WATER HEATER CONTROLS
    • ELECTRIC WATER HEATER ELEMENT REPLACEMENT
    • ELECTRIC WATER HEATER ELEMENT TESTS
    • ELECTRIC WATER HEATER HIGH TEMP CUTOFF TEST
    • ELECTRIC WATER HEATER REPAIR GUIDE
    • Electric Water Heater Reset Switch
    • Electric Water Heater Thermostats
    • Electric Water Heater No Hot Water
    • ELECTRIC WATER HEATER PARTS ID
    • Electric Water Heater Reset & Temp Set
    • Hot Water Temperature & Pressure Valve
    • Water Heater Anode & Dip Tube Check
  • Questions & Answers about the name, location, & function of all of the controls on an electric water heater
  • References

Click to Show or Hide Related Topics

  • WATER HEATERS - home
  • AGE of WATER HEATERS
  • ALTERNATIVE HOT WATER SOURCES
  • ANODES & DIP TUBES on WATER HEATERS
  • ANTI SCALD VALVES / MIXING VALVES
  • BLEVE EXPLOSIONS
  • DRAIN a WATER HEATER TANK
  • ELECTRIC WATER HEATERS
  • FLOODED WATER HEATER REPAIR
  • GAS FIRED WATER HEATERS & GAS HEATERS, HIGH EFFICIENCY
  • HOT WATER IMPROVEMENTS - home
  • HOT WATER DELIVERY SPEED UP
  • HOT WATER EFFICIENCY IMPROVEMENT
  • HOT WATER PRESSURE EXPANSION RATE
  • HOT WATER PRESSURE LOSS
  • HOT WATER PROBLEM DIAGNOSIS
  • HOT WATER QUANTITY IMPROVEMENT
  • HYDROGEN SULFIDE GAS
  • INDIRECT FIRED WATER HEATERS
  • NOISE, WATER HEATER
  • ODORS IN WATER
  • OIL FIRED WATER HEATERS
  • RANGE BOILERS
  • RELIEF VALVE LEAKS
  • RELIEF VALVES - Water Heaters
  • SCALE REMOVAL, WATER HEATERS & SCALE PREVENTION
  • SOLAR HOT WATER HEATERS
  • TANKLESS COILS
  • TANKLESS WATER HEATERS
  • THERMOSTATS, WATER HEATER
  • TIMERS for ELECTRIC WATER HEATERS
  • WATER HEATER AIR INLET
  • WATER HEATER DEBRIS FLUSH
  • WATER HEATER EFFICIENCY
  • WATER HEATER FLUSH PROCEDURE
  • WATER HEATER PROBLEM DIAGNOSIS
  • WATER HEATER PROPERTIES
  • WATER HEATER SAFETY
  • WATER HEATERS for HOME HEATING USE?
  • WINTERIZE A BUILDING
InspectAPedia tolerates no conflicts of interest. We have no relationship with advertisers, products, or services discussed at this website.

Electric water heater controls, switches, & valves: This article describes the location, function, and troubleshooting of 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.

Green links show where you are. © Copyright 2013 InspectAPedia.com, All Rights Reserved. Author Daniel Friedman.

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

Page top sketch is courtesy Carson Dunlop Associates. Reproduction of this web page electronically at other websites is prohibited. Also see TIMERS for ELECTRIC WATER HEATERS. If you cannot find information you need here or if you have comments, questions, suggestions for inspecting and diagnosing water heaters Contact Us

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;
  • An energy-saving timer is installed on some electric water heaters - see TIMERS for ELECTRIC WATER HEATERS

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, including the water heater temperature thermostat next, beginning at Electric Water Heater Repair Guide.

...


Frequently Asked Questions (FAQs) about the controls & switches found on electric water heaters

Question: hot water tank connected to my central heating system is used as an immersion heater

I have a hot water tank which is connected into my central heating system. In the summer
I use it as an immersion heater using electricity. The problem is that the water is too
hot when I use the immersion heater. How can I adjust the water temperature. - John Newing 6/16/11

Reply:

For a water heater that is used for both domestic hot water and heating, I'd suggest adding an automatic mixing valve right at the water heater hot water outlet line. The valve can be set to the desired domestic water temperature for washing and bathing; the valve works by mixing cold in with the outgoing hot.

You can also permanently lower the electric water heater temperature setting by opening the access cover to the control and setting the temperature dial to a lower number.

Also take a look at ANTI SCALD VALVES

Question: water heater output is scalding even with our thermostats set to their lowest settings

With both thermastats set at the lowest setting the water is scalding hot. What is causing this? - Anon 8/12/11

Reply:

Sounds like a bad thermostat control, or two of them. See

  • ELECTRIC WATER HEATER HIGH TEMP CUTOFF TEST
  • Electric Water Heater Thermostats
  • Electric Water Heater Reset & Temp Set

Question: lose pressure when turning on hot water

I have pressure inthe bath tub when the cold water is running, but lose some pressure when turning on the hot water - Aaron 3/12/12

Reply:

Aaron,

Depending on several variables, particularly water piping layout and routing, in some buildings, turning on hot water will, by taking water off of a common cold supply line, cause a drop in cold pressure. Bosch warns of this problem in their installation instructions for their low pressure tankless water heaters, products sold currently mostly out of the U. S. but also sold in that country until about 2004.

Question: our water won't get hot

Water will not get hot when turn on hot water in house - Claude 11/29/12

Reply:

Claude

See ELECTRIC WATER HEATER ELEMENT TESTS - you may need to replace your water heater elements.

Question: can I re-wire my water heater controls to convert from sequential to simultaneous operation?

I understand residential HW heaters are usually sequentially wired.

I want to set up my ordinary 240vac, two-heater, water heater for maximum economy. I will use a 240ac DPST NO relay as a latching relay. One pole to hold the relay in until a thermostat opnes, the other to control the HW heater power. Press a button, the relay latches and stays latched until the HW heater thermostat shuts off the controlling element.

I would like to change the HWH from sequential to simultaneous operation. What are the advantages/disadvantages to this change and are there any dangers in this change.

Thanks,

Norm
Bandership@earthlink.net

Reply:

Norm,

I agree in concept that one could perhaps change all of the electrical components on a given water heater: elements, controls, safety devices, thermostats &c. to convert from one type of water heater operation (sequential) to another (simultaneous) heater element operation, connecting the heater also to a properly wired and sized electrical circuit.

But frankly I would not take a chance on re-wiring a water heater to operate in any manner other than that specified by the manufacturer for that particular heater and model. Doing so could be unsafe. If you're admant about proceeding, start by giving the manufacturer of your heater a call, ask to speak with a technical engineer, and let us know what is her response.

Daniel

...

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Questions & answers or comments about the name, location, & function of all of the controls on an electric water heater.

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Technical Reviewers & References

Related Topics, found near the top of this page suggest articles closely related to this one.

  • Mark Cramer Inspection Services Mark Cramer, Tampa Florida, Mr. Cramer is a past president of ASHI, the American Society of Home Inspectors and is a Florida home inspector and home inspection educator. Mr. Cramer serves on the ASHI Home Inspection Standards. Contact Mark Cramer at: 727-595-4211 mark@BestTampaInspector.com
  • John Cranor is an ASHI member and a home inspector (The House Whisperer) is located in Glen Allen, VA 23060. He is also a contributor to InspectApedia.com in several technical areas such as plumbing and appliances (dryer vents). Contact Mr. Cranor at 804-747-7747 or by Email: johncranor@verizon.net
  • Carson, Dunlop &
Associates Ltd., TorontoCarson, Dunlop & Associates Ltd., 120 Carlton Street Suite 407, Toronto ON M5A 4K2. (416) 964-9415 1-800-268-7070 info@carsondunlop.com. The firm provides professional home inspection services & home inspection education & publications. Alan Carson is a past president of ASHI, the American Society of Home Inspectors. Thanks to Alan Carson and Bob Dunlop, for permission for InspectAPedia to use text excerpts from The Home Reference Book & illustrations from The Illustrated Home. Carson Dunlop Associates' provides:
    • Commercial Building Inspection Courses - protocol ASTM Standard E 2018-08 for Property Condition Assessments
    • Home Inspection Education Courses including home study & live classes at eleven colleges & universities.
    • Home Inspection Education Home Study Courses - ASHI@Home Training 10-course program.
      Special Offer: Carson Dunlop Associates offers InspectAPedia readers in the U.S.A. a 5% discount on these courses: Enter INSPECTAHITP in the order payment page "Promo/Redemption" space. InspectAPedia.com editor Daniel Friedman is a contributing author.
    • The Home Reference Book, a reference & inspection report product for building owners & inspectors.
      Special Offer: For a 10% discount on any number of copies of the Home Reference Book purchased as a single order. Enter INSPECTAHRB in the order payment page "Promo/Redemption" space. InspectAPedia.com editor Daniel Friedman is a contributing author.
    • The Home Reference eBook, an electronic version for PCs, the iPad, iPhone, & Android smart phones.
      Special Offer: For a 5% discount on any number of copies of the Home Reference eBook purchased as a single order. Enter inspectaehrb in the order payment page "Promo/Redemption" space.
    • The Illustrated Home illustrates construction details and building components, a reference for owners & inspectors.
      Special Offer: For a 5% discount on any number of copies of the Illustrated Home purchased as a single order Enter INSPECTAILL in the order payment page "Promo/Redemption" space.
    • The Horizon Software System manages business operations,scheduling, & inspection report writing using Carson Dunlop's knowledge base & color images. The Horizon system runs on always-available cloud-based software for office computers, laptops, tablets, iPad, Android, & other smartphones.

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

  • Our recommended books about building & mechanical systems design, inspection, problem diagnosis, and repair, and about indoor environment and IAQ testing, diagnosis, and cleanup are at the InspectAPedia Bookstore. Also see our Book Reviews - InspectAPedia.
  • Home Reference Book - Carson DunlopThe Home Reference Book - the Encyclopedia of Homes, Carson Dunlop & Associates, Toronto, Ontario, 25th Ed., 2012, is a bound volume of more than 450 illustrated pages that assist home inspectors and home owners in the inspection and detection of problems on buildings. The text is intended as a reference guide to help building owners operate and maintain their home effectively. Field inspection worksheets are included at the back of the volume. Special Offer: For a 10% discount on any number of copies of the Home Reference Book purchased as a single order. Enter INSPECTAHRB in the order payment page "Promo/Redemption" space. InspectAPedia.com editor Daniel Friedman is a contributing author.

    Or choose the The Home Reference eBook for PCs, Macs, Kindle, iPad, iPhone, or Android Smart Phones. Special Offer: For a 5% discount on any number of copies of the Home Reference eBook purchased as a single order. Enter INSPECTAEHRB in the order payment page "Promo/Redemption" space.
  • Carbon Monoxide Gas Toxicity, exposure limits, poisoning symptoms, and inspecting buildings for CO hazards
  • ...

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