Water Heaters

water heaters    

Most people don't give much thought to their water heater - they just turn on the faucet and expect hot water to come out. Well, it's not that easy. There's maintenance to perform on your water heater if you would like continue receiving hot water. I recommend keeping your water heater in peak operating condition by performing some very simple maintenance tasks.

1.) Once every six months (when you turn your clocks back or forward), drain one or two gallons of water from the tank. The valve for draining is located at the lower portion of your water heater. If you have hard water, drain a gallon every month. This reduces the amount of sediment collecting in the bottom of the tank, which can make the burner or heating coils work harder. Which, in turn, will give your water heater a shorter life expectancy.

2.) Once every two years, have your water heater inspected by a licensed Plumber. This will help keep it in peak operating condition, and will prevent dangerous carbon monoxide problems.

And don't forget: Before doing any maintenance on your water heater, shut off power at the service panel and read your owner's manual. Some repair attempts you make could void the warranty.



As a rule of thumb, the least expensive water heater is the most expensive to operate. With this in mind, lets examine the various considerations you should take before purchasing your next water heater. I'm going to suggest what size or capacity water heater you will need for your home.


Small to Medium Home with 1-2 people (1 bath, Clothes Washer)

You will need a 40 gallon electric or 30 gallon gas/propane/oil water heater or an on-demand tankless water heater.


Medium Home with 3 people (1.5 baths, Clothes Washer, Dishwasher)

You will need a 50 gallon electric or a 40 gallon gas/propane/oil water heater or an on-demand tankless water heater.


Medium/Large Home with 4 people (2 baths, Clothes Washer and Dishwasher)

You will need a 75 gallon electric or a 50 gallon gas/propane/oil water heater or an on-demand tankless water heater.


Large Home with 5 people (2+ baths, Heavy-duty Clothes Washer and Dishwasher)

You will need an 80 gallon electric or a 50 gallon (or more) gas/propane/oil water heater or an on-demand tankless water heater.


This scale is simply my personal opinion from home inspection experience. Factors such as whirlpools and hot tubs should also factor in and be weighed in when making your decision to purchase your new water heater. Check with your local Licensed Plumbing professionals for more accurate sizing.




The most popular for residential water heating. They operate by releasing hot water from the top of the tank when a hot water tap is on. Cold water is introduced to the bottom of the tank as hot water is drawn. These tanks operate on electric, gas, propane, and oil. Because the water is constantly heated with this system, energy can be wasted even when not being used. This is referred to as "standby heat loss". Consider tanks with at least 1.5 inches (3.8 centimeters) of foam insulation and energy efficiency rating shown on the Energy Guide labels. Insulation is instrumental in the prevention of standby heat loss.



Also commonly known as "Instantaneous" water heating. This system significantly reduces standby heat loss and reduces energy consumption by 20-30%. With these systems you never run out of hot water. Cold water travels through a heat exchanger within the unit, and either a gas burner or electric element heats the water on demand. The biggest drawback to this system is limited flow rate. Demand heaters provide hot water at a rate of 2 to 5 gallons per minute. More than adequate if operating hot water at one location at a time. However inadequate if two or more are operating at the same time (i.e. shower and clothes washer). For additional costs, demand heaters can be installed in parallel sequence allowing or meeting hot water demands for multiple faucets operating at the same time. Gas fired demand heaters tend to have higher flow rates than electric.

How to maintain a DEMAND TYPE water heater


Electric systems that move heat from one place to another instead of generating heat directly in one spot. They operate in the same manner as refrigerators only in reverse. They can act alone with built-in storage tanks or as add-ons to existing water heaters. They have a high initial cost and require installation in locations they maintain a 40 degree or higher temperature yearlong. To operate most efficiently, they should be placed in areas having excess heat, such as a furnace room. They will not function properly in a cold space.


TANKLESS COIL/INDIRECT TYPES (They operate off your home heating system.)

Tankless Coil - No separate storage tank is needed in the tank less coil water heater system. Water is heated directly inside the boiler in a hydronic (i.e. hot water) heating system unit. Water flows through a heat exchanger in the boiler whenever a hot water tap is turned on. During the heating season, the tank less coil works well because the heating system is used regularly. The system is less efficient during warmer clients when the boiler is used less frequently.

Indirect - Requires a separate storage tank. Uses the same method of heating water (through a heat exchanger) as the tank less coil system. However, this heated water then flows to an insulated storage tank (most carry a lifetime warranty.). This system is more efficient than the tank less coil because the boiler does not need to operate frequently. When an indirect water heater is used with a highly efficient boiler they combine for one of the least expensive methods of water heating.



Strongly dependent on the sun, solar water heaters if properly designed, installed and maintained can satisfy half to nearly all of a home's hot water demand. System designs are either classified as passive, active or direct. The initial costs are high but overall operating costs are significantly lower.

Passive systems operate without pumps and controls and can be more reliable, durable, less maintenance, longer lasting, and less expensive to operate than active systems. Active solar water heaters require pumps and controls to move heat-transfer fluids from collectors to storage tanks. Both systems often require conventional water heaters as back-ups.

A direct solar water heating system circulates water through collectors and is not appropriate or recommended in climates in which freezing temperatures occur.




Things that you should be aware of especially if you are:

- Converting to a gas or oil-fired water heater in an electrically heated home.

In this instance, since no chimney will be available, you have the option of installing a direct vent or power vented gas or oil water heater. Flue gases are extracted through the sidewall of the home.


- Converting from an oil-fired water heater to a propane or gas model.

May require that your existing chimney or vent to be re-sized and the liner changed to maintain adequate draft to avoid condensation in the vent system. Alternatively, a direct vent or power vented unit could be installed.


- Replacing an existing gas, propane or oil-fired water heater with a more efficient model.

Sidewall venting may be the only practical option because of the potential increase in condensation formed in the venting system.


- Replacing an existing gas, propane, or oil-fired water heater with an electric water heater.

Electric water heaters require no venting. They are simple to install and can be located in many areas of the home.



Most municipalities require permits, etc. prior to installation/replacement of water heater systems. Consult your local code officials for details. As always if you feel uncomfortable performing any of these tasks, please consult a licensed Plumber.



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Hi Dave,

I just wanted to write a quick thank you for your work inspecting 43 1/2 Bartholomew Street in Peabody yesterday. As a buyer in the process of trying to purchase my first home, it's been difficult to know who to trust. I honestly cannot believe some of the stuff I've run into, so I had to write & let you know that I found you professional, competent, & all around above par. In all of the people I've had to deal with up to this point, you were one of the few that actually took the time to explain things in a way that an inexperienced first time home buyer would understand. I never once felt rushed or talked down to.

Based on your inspection, I've decided not to purchase the home at 43 1/2 Bartholomew Street. I will however, continue to look & will hopefully find a house more suited to my needs in the near future. When that happens I will be calling on your expertise once again. In the meantime, I will certainly recommend you to any of my family & friends that may need a home inspection.

Thanks again,

Lisa G.


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Last updated on  May 13, 2020