Hot Water System Inspections

Heimer Engineering uses Professional Engineer Inspectors
to perform Home, Building, Condo, and Co-op Inspections in
Manhattan, Queens, Brooklyn, Bronx, Staten Island,
Nassau, Suffolk, Rockland, Putnam, and Westchester

Insight Only A Professional Engineer Inspector Offers


Gas fired hot water boiler In residences (including home, condos, and co-ops), the hot water is used for bathing and cleaning.  In some buildings, the hot water serves to sterilize equipment that is used by the general public.  Besides comfort, hot water serves a vital role in maintaining good health.  To serve this role, the hot water must be produced at an appropriate temperature.

Most homes, buildings, condo units, and co-op units have a tankless hot water heater, a hot water heater with a storage tank, a hot water booster tank, or an indirect-fired hot water heater.  A comparison of the different types of hot water systems is found later on this page.

The Licensed Professional Engineers of Heimer Engineering evaluate the hot water system in the home or building you are considering purchasing and advises you if it is sufficient.  You are also advised of the need to budget for upcoming replacement of the hot water heater.  The expense analysis in the engineering report helps you.

Hot Water Temperature

ThermometerIn homes, buildings, condos, and co-ops, the temperature of the hot water should be around 120 degrees Fahrenheit, although some dishwasher manufacturers recommend 130 degrees Fahrenheit to assure that the dishes will be properly cleaned and sterilized.  Lower temperatures are recommended by others to reduce the risk of scalding and reduce energy consumption.  A lower temperature, however, increases the risk of bacteria growth.

Hot water that would scald in seconds at 140 degrees Fahrenheit will take minutes to cause the same level of injury at less than 120 degrees Fahrenheit.  Many hot water systems produce hot water at well over 130 degrees Fahrenheit.

The risk of scalding or serious burns, especially to children and elderly people, is high.  When possible, Heimer Engineering's Engineers measure the hot water temperature and advises you of hazards.

Hot Water Heater Life Expectancy

Hot water heater life expectancy varies dramatically depending on the type of hot water heater.  A tankless hot water heater can last as long as the heating system in which it is mounted, although effectiveness may diminish over time.  An automatic storage hot water heater, hot water booster tank, or an indirect-fired hot water heater typically lasts from seven to 15 years.  Heimer Engineering evaluates the hot water system, and advises you of remaining life expectancy.

Tankless Hot Water Heaters

Tankless hot water heaterA tankless hot water heater heats the water by circulating it through coils inside a boiler.  As the water circulates through the coils, it is heated.

Tankless hot water heaters often suffer from performance problems, especially as they age.  Many systems start out at an initial temperature hot enough to scald.  After running for a short time, this hot temperature may fall to a relatively low temperature.  To help overcome this problem, many people install hot water booster tanks in conjunction with a tankless hot water heater.

A variation of the tankless hot water heater is the instant hot water heater, sometimes called the demand hot water heater.  In an instant hot water heater, water passes over a heat exchanger.  The heat exchanger is kept warm, usually by a gas flame or electric coil.  See the hot water heater comparison below for more information on tankless hot water heaters.

Hot Water Booster Tanks

Hot water faucetA hot water booster tank works in conjunction with a tankless hot water heater.  Most hot water booster tanks are small hot water heaters.  The water is pre-heated in the tankless hot water heater.  The heated water than circulates into the hot water booster tank.  The hot water booster tank stores the hot water, and warms it if necessary.  This increases the amount of available hot water, although at the cost of greater energy consumption.  Often, hot water boosted booster tanks are electric, which makes them expensive to operate.

See the hot water heater comparison below for more information on hot water booster tanks.

Hot Water Heaters With Storage Tanks

Gas fired hot water heaterWhen many people say hot water heater, they are typically referring to a single unit that both heats and stores the water.  This type of unit is sometimes called an automatic storage hot water heater.  This type of unit must have some method of heating the water (typically oil, gas, or electricity) along with a tank to store the heated water.

The size of the storage tank typically varies between 30 gallons and 120 gallons, depending on the type of fuel used and the amount of hot water needed. The Engineers of Heimer Engineering evaluate both the fuel and the hot water demands to determine if the hot water heater is sufficient in size.  See the hot water heater comparison below for more information on hot water heaters with storage tanks.

Indirect-Fired Hot Water Heaters

Indirect fired hot water heaterAn indirect-fired hot water heater consists of a storage tank, a circulator pump, and a boiler that serves as a heat source.  The boiler (and the water is contains) is kept hot.  When the storage tank of hot water falls below a certain temperature, an aquastat activates the circulator pump.  The boiler-heated water is circulated through coils in the hot water storage tank.

This process heats the water in the storage tank.  The water heated in the boiler never contacts the water in the storage tank.

In the Metro New York area (with its half-year heating season), an indirect-fired hot water heater might be less expensive to operate than a separate hot water heater.  See the hot water heater comparison below for more information on indirect-fired hot water heaters.

Comparison of Hot Water Heaters




Tankless Hot Water Heaters

Demand Hot Water Heaters
  • Quickly heats hot water
  • Unlimited hot water availability (at a slow flow rate)
  • Potential temperature fluctuations during use
  • Risk of scalding due to temperature fluctuations
  • Boiler must be on all year
  • Effectiveness deteriorates with age
  • Requires periodic cleaning to maintain performance
Hot Water Storage Tank (Used with a tankless hot water heater)
  • Can improve performance of a marginal tankless hot water heater
  • May be less expensive than replacing a tankless hot water heater
  • May be very slow to reheat when the hot water is depleted
  • Risk of scalding hot water
Hot Water Booster Tank
  • Can improve the performance of a marginal tankless hot water heater
  • Depending on design, may be slow to reheat when hot water is depleted
  • Risk of scalding hot water
  • Requires fuel or electricity, which increases the cost of operation
Oil-Fired Hot Water Heater with a storage tank
  • Hot water is heated quickly
  • Can be used in areas not served by gas
  • Highest cost of installation
  • Oil requires delivery
  • Oil price fluctuations
  • Older equipment can be noisy, dirty, and difficult to maintain
  • Risk of an oil leak and environmental contamination
  • Occasional odors
  • Risk of puffbacks
  • Electricity to run oil burner adds to cost of operation
Gas-Fired Hot Water Heater with a storage tank
  • Relatively low cost of installation
  • Requires minimal routine maintenance
  • Plentiful gas supply is assured by the local gas supplier
  • Equipment is quiet
  • Heats water much slower than oil
  • Gas may not be available in your area
Electric Hot Water Heater
  • Can be installed where no oil or gas is available, such as in an apartment
  • Plentiful supply of electricity is assured by local electricity supplier
  • Requires minimal routine maintenance
  • Does not require ventilation
  • Relatively low cost of installation
  • Equipment is quiet
  • Very high expense, especially in the Metro New York area
  • Hot water heating is extremely slow
Indirect-Fired Hot Water Heater
  • Produces ample hot water
  • Requires minimal routine maintenance
  • Can be located far from the boiler and in an unvented area
  • Relatively low cost of operation
  • Reduced hot water availability during the heating season

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Heimer Engineering's Engineer Inspectors perform pre-purchase home, building, condo, and co-op inspections, and provide other Engineering services in the State of New York. We do not provide contracting, construction, building, or repair services, and are not affiliated with or franchised by ay society, organization, other company, or the Department of Buildings.