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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 VALVE, HEATING SYS
BACKFLOW PREVENTER, HEATER WATER FEEDER
BACKUP HEAT for HEAT PUMPS
CARBON MONOXIDE - CO
CHECK VALVES, WATER SUPPLY
CHEMICAL CONTAMINANTS in WATER
CHIMNEY INSPECTION DIAGNOSIS REPAIR
CLOGGED DRAIN DIAGNOSIS & REPAIR
CLOGGED SUPPLY PIPING
CROSS CONNECTIONS, PLUMBING
DEBRIS in WATER SUPPLY, Water Heater
DRAIN a WATER HEATER TANK
ELECTRIC WATER HEATERS
FLOODED HEATING EQUIPMENT REPAIR
FLOODED WATER HEATER REPAIR
FREEZE-PROOF A BUILDING
FROST HEAVES, FOUNDATION, SLAB
GALVANIC SCALE & METAL CORROSION
GAS BURNER Flame & Noise Defects
GAS FIRED WATER HEATERS
GAS PIPING, VALVES, CONTROLS
HEAT TAPES, Heat, Insulation prevent Freeze-Up
HEATING COST FUEL & BTU Cost Table
HEATING COST SAVINGS METHODS
HOT WATER SUPPLY
HOT WATER IMPROVEMENTS
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
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
PLUMBING VENT DEFECTS & NOISES
PUMPS, HEAT PUMPS
PUMPS, OIL BURNER
PUMPS, PONY PUMPS
PUMPS, SEPTIC PUMPS
PUMPS, SEWAGE EJECTOR / GRINDER PUMPS
PUMPS, SUMP PUMPS
PUMPS, WATER PUMPS
PUMPS, WATER REPAIR
RELIEF VALVE LEAKS
RELIEF VALVES - TP Valves on Boilers
RELIEF VALVES - STEAM TP VALVES
RELIEF VALVES - Water Heaters
RELIEF VALVES - Water Tanks
SAFETY, HEATING INSPECTION
SCALE REMOVAL, WATER HEATERS
SEWER GAS ODORS
SOLAR HOT WATER HEATERS
SOOT on OIL FIRED HEATING EQUIPMENT
SPILL SWITCHES - Flue Gas Detection
TANKLESS WATER HEATERS
THERMOSTATS, HEATING / COOLING
THERMOSTATS, WATER HEATER
TIMERS for ELECTRIC WATER HEATERS
WATER CONTAMINANT LEVELS
WATER HAMMER NOISE DIAGNOSE & CURE
WATER HEATER ALTERNATIVES
WATER HEATER ANODES, DIP TUBES
WATER HEATER AIR INLET
WATER HEATER DEBRIS FLUSH
WATER HEATER EFFICIENCY
WATER HEATER FLUSH PROCEDURE
WATER HEATER NOISES
WATER HEATER PROBLEM DIAGNOSIS
WATER HEATER PROPERTIES
WATER HEATER SCALE - De-Liming Procedure
WATER HEATER SCALE PREVENTION
WATER HEATER SAFETY
WATER HEATERS for HOME HEATING USE?
WATER ODORS, CAUSE CURE
WATER PIPES, Clogs Leaks Types
WATER PRESSURE & FLOW MEASUREMENT
WATER PRESSURE GAUGE ACCURACY
WATER PRESSURE LOSS DIAGNOSIS & REPAIR
WATER PRESSURE REDUCER / REGULATOR
WATER PRESSURE PUMP REPAIR GUIDE
WATER PUMPS, TANKS, TESTS, WELLS, REPAIRS
WATER PUMP REPAIR GUIDE
WATER QUALITY TESTS, CONTAMINANTS, TREATMENT
WATER QUANTITY IMPROVEMENT
WATER SOFTENERS & CONDITIONERS
WINTERIZE A BUILDING
This article gives a definition of water heater anodes or dip tubes, explains what they are for, how they work, and what goes wrong with anodes and dip tubes. A corroded or damaged dip tube or water heater anode can cause loss of hot water, water heater odors, and even debris showing up in the building water supply. The articles at this website will answer most questions about residential and light commercial water heaters as well as many other building plumbing system inspection or defect topics. Page top water heater drawing showing the sacrificial anode on a water heater is provided courtesy Carson Dunlop Associates, used with permission.
Green links show where you are. © Copyright 2013 InspectAPedia.com, All Rights Reserved. Author Daniel Friedman.
Reduced hot water pressure and flow and also sulphur smells or similar water odors in the hot water supply as well as debris in the water supply system might all be traced to problems with a water heater anode or dip tube. Accumulated debris in a water heater, and debris from a corroded or disintegrating hot water tank dip tube or hot water tank sacrificial anode can also block the hot water outlet opening, resulting in low hot water pressure in a building.
Below we discuss the water heater anode and water heater dip tube in detail. Also see WATER HEATER DEBRIS FLUSH This article describes the diagnosis and cure of debris in the building water supply traced to a deteriorated water heater dip tube/anode. Also see Water pipe clog diagnosis and WATER HEATER SCALE - De-Liming Procedure for further diagnosis and repair procedures of bad hot water pressure and flow in a building. But if both cold water pressure/flow and hot water pressure/flow are slow or inadequate, readers should see WATER PRESSURE LOSS DIAGNOSIS & REPAIR.
Functions of a Water Heater Tank Dip Tube:
The water heater tank dip tube, often made of a special metal to combine its function with that of a water heater tank sacrificial anode (to reduce water tank corrosion and leaks) performs these functions:
Functions of the Water Heater Anode
By inserting into the water heater tank a rod made of a metal which is more readily corroded than the steel of a steel hot water tank, the sacrificial anode protects the hot water tank from early failure due to corrosion. An illustration of the water heater anode is shown at the top of this page.
Low Hot Water Temperature Traced to Depleted Combination Dip-Tube & Sacrificial Anode
Sulphur or Rotten Egg Smells in Hot Water Supply Traced to Water Heater Anode Problems
The role of the sacrificial anode is to protect a glass-lined steel water heater tank itself from corrosion - the water heater anode rod will gradually deteriorate or basically "dissolve" over the life of the water heater. The rate of water heater anode depletion depends on the chemistry of the water supply (more aggressive water is more corrosive), and the amount of usage of the water heater - how much hot water is used in the building.
Watch out: if the water heater sacrificial anode rod completely dissolves or depletes, the water tank itself is no longer protected from corrosion and the tank may be damaged and its life significantly reduced.
If your hot water smells like rotten eggs, and especially if it's only the hot water, not also the cold water supply, 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.
If the building water supply contains dissolved hydrogen sulfide gas (H2S), (also potentially explosive - see Hydrogen Sulfide Gas), then the combination of water chemistry and the presence of the sacrificial anode in the water heater tank can produce black debris in the water supply and an increased level of sulphur or rotten egg smells in the building hot water supply. In fact if there is significant H2S in the water supply even the cold water may smell like rotten eggs. In our experience with private well water that contained H2S, the odor level varied by time of year, level of the water table in the ground, and usage of the well. Often returning from a month of vacation the homeowner would notice a stronger rotten egg smell in the building water supply.
If your water supply contains high levels of hydrogen sulfide, enough to smell, you should check with your plumber or your water heater manufacturer about purchasing and installing a special sacrificial anode that can reduce this smell problem in the building hot water system. Additional water treatment to remove sulphur may also be needed.
Corrosive Water Supply Reduces Anode & Water Heater Tank Life
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.
Another cause of H2S odors in hot water may be traced to homes that use a water softener to treat their incoming water supply. Water that is high in salt ions (a water softener may replace calcium or magnesium with sodium or salt ions in the process of "softening" a hard water supply), can be extra corrosive in the water heater and can reduce the life of both the sacrificial anode and the water heater tank itself.
At Odors in Water we discuss the general problem of diagnosing and curing odors in water; also see Odors, Smells, Gases in buildings-Diagnosis & Cure.
We provide a detailed list of sewer and sulphur gas odor sources at Sources of Sulphur Odors in buildings. Also CHINESE DRYWALL HAZARDS discusses Chinese drywall odors, sulphur smells, and corrosive outgassing hazards in buildings. Major costs to remove this product, repair or replace electrical wiring, plumbing, and HVAC components may be involved, and there may be immediate safety hazards due to damaged smoke detectors or carbon monoxide detectors in buildings where Chinese drywall outgassing has caused damage.
Procedure to inspect a water heater Sacrificial Anode or Dip Tube
How Often Should the Water Heater Sacrificial Anode be Inspected?
How to Replace the Water Heater Anode Rod - step by step
A higher hose destination will prevent the water heater tank from draining. If your water heater drain valve happens to be high enough above the floor you can skip the hose hookup and just use a plastic pan or bucket as we show in our photo (below left).
How Long Should A Water Heater Last?
See AGE of WATER HEATERS for the answer as well as for our list of factors that affect water heater life.
Frequently Asked Questions (FAQs)
Questions & answers or comments about water heater anodes & dip tubes: water heater odors, corrosion, leaks, & tepid hot water troubleshooting.
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Technical Reviewers & References
Related Topics, found near the top of this page suggest articles closely related to this one.