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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, HEATER WATER FEEDER
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
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 WATER HEATERS
Temperature Pressure Relief Valves - Water Heaters
THERMOSTATS, WATER HEATER
TIMERS for ELECTRIC WATER HEATERS
WATER CONTAMINANT LEVELS
WATER HAMMER NOISE DIAGNOSE & CURE
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
How to flush out a water heater - detailed procedure: this article explains in detail the procedure for flushing out a water heater to remove waterborne mud, dirt, or debris that can cause water heater noises and may shorten the life of the water heater or reduce the amount of hot water available.
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The articles at this website will answer most questions about diagnosing and curing noisy domestic water heaters and about the procedure to remove mineral deposits, lime, water scale, silicates, sulfates, aluminates, or silt and sand from a water heater tank.
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. And see WATER HEATER NOISES and WATER HEATER SAFETY. For the broad topic of controlling plumbing noises in buildings see Sound Control for Plumbing.
This article series starts at WATER HEATER NOISES.
Lime or scale in plumbing systems is caused by hard water as well as silicates, sulfates, and similar materials form water scale that coats the bottom of a hot water tank or the surface of the electrodes in an electric water heater, interfering with proper water heater operation, causing water heater noises, reduction in hot water quantity, increased water heater operating costs, and a shorter water heater life. Silt and soil debris can also collect in a water heater tank where it can cause similar problems even if the water supply is not hard.
Silt and debris can be easily removed from a hot water tank by periodic flushing. In fact if your water heater is quite noisy, it will probably be easier to remove un-wanted mineral deposits from the water tank than it will be later if you wait until the heater is no longer making much noise (because the mineral layer has solidified). Install a sediment filter on the incoming water supply to avoid this problem in the first place.
But lime or water scale are more difficult to remove from a water heater: manually scraping the tank bottom through the drain opening or use of a de-limer chemical will be needed. Below we describe these procedures. Readers should also see our discussion of mineral clogging of water piping, water heaters, and tankless coils, organized at HOT WATER IMPROVEMENTS. Other gas fired water heater noises are discussed at Gas Flame & Noise Defects.
Watch out: Safety Warnings: don't tackle this water heater cleanout project on a Sunday night when you can't call a plumber or buy a replacement part. Water heaters, their heating source (oil or gas burner or electricity or solar hot water), and particularly their relief valves include critical safety components. Do not modify or remove relief valves, chimney connections, draft hoods, etc. as you may create dangerous conditions.
Watch out: cleaning and de-liming chemicals such as rust or lime removers can be dangerous if not used according to the manufacturer's instructions. See Lime Out / Lime Out Extra, lime remover MSDS, a Summit Brands product and see Super Iron Out, MSDS Material Data Safety Sheet rust and stain remover, also from Summit Brands.
Our photo (left) shows scale deposits removed from a water heater tank. Here are the steps the plumber followed to get this mineral debris out of the tank bottom:
Additional tips on draining a water heater tank can be found at ELECTRIC WATER HEATERS
How to Let Air Into the Hot Water Tank to Speed the Tank Draining Process
This article explains using or removing temperature and pressure relief valves on residential water heaters to let air into the hot water tank during draining for cleaning or other purposes. For more details about water heater safety valves see RELIEF VALVES - Water Heaters and for a discussion of temperature and pressure relief valves used as safety devices on heating boilers please see Relief Valves - TP Valves on Boilers.
This article series continues at Water Heater Scale Removal Procedure.
After flushing out the water heater tank, the second step in curing water heater noise or insufficient hot water is to remove scale or lime from the water heater tank. If the unit is an electric water heater, you'll also need to remove scale from the electric water heater elements. See Water Heater Scale Removal Procedure for the full article on the detailed procedure for removing lime and water heater scale.
Frequently Asked Questions (FAQs)
Questions & answers or comments about how to flush out or clean out a water heater.
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Technical Reviewers & References
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