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AGE of WATER HEATERS
ALTERNATIVE HOT WATER SOURCES
ANODES & DIP TUBES on WATER HEATERS
ANTI SCALD VALVES
APPLIANCE EFFICIENCY RATINGS
AQUASTAT CONTROL Functions
BACKDRAFTING HEATING EQUIPMENT
BACKFLOW PREVENTER, HEATER WATER FEEDER
CARBON MONOXIDE - CO
CHECK VALVES, WATER SUPPLY
CLOGGED SUPPLY PIPING
CROSS CONNECTIONS, PLUMBING
DEBRIS in WATER SUPPLY, Water Heater
DRAIN a WATER HEATER TANK
ELECTRIC WATER HEATERS
FLOODED WATER HEATER REPAIR
FREEZE-PROOF A BUILDING
GALVANIC SCALE & METAL CORROSION
GAS BURNER Flame & Noise Defects
GAS FIRED WATER HEATERS
GAS PIPING, VALVES, CONTROLS
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, WATER HEATER
ODORS IN WATER
PIPING IN buildings, Clogs Leaks Types
RELIEF VALVE LEAKS
RELIEF VALVES - Water Heaters
SCALE REMOVAL, WATER HEATERS
SEWER GAS ODORS
SOLAR HOT WATER HEATERS
TANKLESS WATER HEATERS
THERMAL EXPANSION of HOT WATER
THERMOSTATS, WATER HEATER
TIMERS for ELECTRIC WATER HEATERS
WATER HEATER ALTERNATIVES
WATER HEATER ANODES, DIP TUBES
WATER HEATER AIR INLET
WATER HEATER DEBRIS FLUSH
WATER HEATER DRAIN PROCEDURE
WATER HEATER EFFICIENCY
WATER HEATER FLUSH PROCEDURE
WATER HEATER NOISES
WATER HEATER PROBLEM DIAGNOSIS
WATER HEATER PROPERTIES
WATER HEATER SCALE
WATER HEATER SAFETY
WATER HEATERS for HOME HEATING USE?
WATER ODORS, CAUSE CURE
WATER PIPES, Clogs Leaks Types
WATER PRESSURE TOO HIGH: DANGERS
WATER PRESSURE LOSS DIAGNOSIS & REPAIR
WATER QUANTITY IMPROVEMENT
WATER SOFTENERS & CONDITIONERS
WINTERIZE A BUILDING
This article explains how to improve the total quantity of hot water available from your water heating system. We explain how to increase the total hot water quantity available from your water heater and how to improve the hot water flow rate if your hot water runs too slowly. We also discuss how much hot water to expect from your water heater. We make hot water quantity improvement suggestions here and we also give a list of detailed diagnostic articles to fix insufficient hot water quantity or flow.
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Thanks to Carson Dunlop, a Toronto Home Inspection Firm and Home Inspection Educator, for permission to use sketches shown in this article.
Before you start fixing or buying stuff to fix a hot water problem hot water problems and diagnostic guides for all kinds of hot water troubles are summarized at WATER HEATER PROBLEM DIAGNOSIS. You might want to check there to be sure you're fixing the right problem.
Question: My 40 gallon hot water tank is not giving me 40 gallons of really hot water. Why?
How much hot water should I expect from my new 50 gallon hot water heater? I'm getting 32 gallons before the next 4 gallon bucket starts cooling and runs cold. - J.
Reply: List of factors that determine how much hot water you get out of a water heater tank
You didn't indicate the type of water heater. If your heater is electric, and if the lower heating element has burned out, the total quantity of hot water from the heater would be significantly reduced. (By contrast if the upper element is burned out the total quantity may not be reduced but the temperature of the hot water will be lower).
Some other factors that determine just how much hot water you get out of a water heater of a given size (that is without changing the size of the water heater tank) are:
Having a greater quantity of hot water (more total hot water volume available) also opens the way to taking steps to improve hot water pressure and flow rate in a building. On the other hand, if we increase hot water pressure or flow but lack adequate hot water quantity, the result is we just run out of hot water faster than ever. The approach to improving hot water quantity itself involves these ideas:
Hot Water Quantity Diagnosis & Improvement Articles
As Carson Dunlop Associates' illustration (left) shows, one way to improve hot quantity in a building is by hooking up more than one water heater, in parallel or in series.
The articles listed below offer more details about steps one can take to increase hot water quantity, pressure, and flow in a building.
Below we list hot water quantity, pressure & flow problem diagnosis, repair, and improvement articles. For each item we decribe how the topic pertains to hot water quantity, pressure, or flow complaints.
The list below is in alphabetic order, not in order of priority of things to try. Diagnosis and repair for hot water temperature and more about hot water pressure are explained separately at HOT WATER IMPROVEMENTS. Please Contact Us if you think we should re-order or add to this list.
Active water pre-heating tank: install a water heater (oil, gas, solar, electric) on the water piping upstream, that is, before water enters the tankless coil (or primary water heating tank, whatever water heating method is used).
This water tank can be left off when there is not much demand for hot water, in which case it will function as a passive water pre-warming tank as we discussed above. When a greater quantity of hot water is going to be needed (say many weekend visitors to a building), turn on the water heater to permit it to "boost" hot water headed for the tankless coil.
As occupants in the building draw hot water out of the system, heat will be drawn from the heating boiler and tankless coil at a very low rate, possibly not at all, until we've exhausted the hot water that was stored in the separate water heater tank.
Some people install this system backwards: hot water is fed from the tankless coil into a water heater tank. This is a much less efficient way to make hot water as all of the water entering the water heater tank will always cause the heating boiler to run. We do not recommend this arrangement.
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Technical Reviewers & References
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