A point of use water heater can not only save energy and water but also aggravation. No more waiting for the water to get hot so you can wash your hands.
Point of use water heaters are ideal for remote sinks, work shops, campers, out door kitchens, kitchenettes, anywhere you need hot water fast.
They can be installed independently or inline with your existing water heater.
Check small water heater prices on our electric water heater parts page.
About point of use water heaters
They are also known as under sink or inline water heaters. Most units are electric to eliminate the need for venting.
They come in tankless or storage (tank). The smaller storage water heaters can be
mounted under the sink, hung on the wall or sit on the floor.
The smaller tankless water heaters can be mounted under the sink also.
A larger unit can supply a shower or two to three sinks depending on your needs.
Electric Tankless Water Heaters
Tankless water heaters are rated as gallons per minute (gpm). Smaller units come with low flow aerators to install on the faucet.
The gallon per minute is based on 70 degree incoming or ground water temperature and 120 degree hot water temperature.
If you live in an area with cold winters and have an incoming water temperature of 40 degrees the gallons per minute will be reduced significantly.
Two gallons per minute should do fine for hand washing. Anything more than that, figure how much hot water you'll need and buy a unit that will supply that amount plus a little more.
Small tankless water heaters will come with a flow restriction device, some
units also include a low flow aerator for your faucet.
Their are 120 volt systems on the market but their capabilities are minimal.
A 240 volt system has enough power to give you hot water without slowing it to a trickle.
Before you purchase a tankless water heater be sure that your
breaker box can handle the extra load.
If you live in an area with hard water you should also install an inline water softener.
Small Electric Water Heater (Storage)
Most small storage waters heaters are rated as gallons per hour (gph) at
a 90 degree rise.
If a water heater thermostat is sat at 140 degrees and the incoming water temperature is 50 degrees the water heater could heat this water to 140 degrees and give you x gph.
Of course if the incoming water temperature is 70 degrees instead of 40 degrees you will have more than the rated gph.
Some water heaters are rated as recovery time. Recovery time is the time it would take to heat a tank of water if it has been deleted of hot water.
The heating element wattage and tank size will determine the recovery rate. Most small compact water heaters will have an element range from 1200 to 1500 watts.
The smallest tank point of use water heater is 2.5 gallons. This water heater would be large enough for a hand washing sink.
You should get 60 to 70 percent of the water heater's capacity in usable hot water. A 2.5 gallon water heater would produce about 1.7 gallons of hot water.
A small electric water heater should be flushed out once a year and the anode rod check/replaced every 3-5 years.
Installing a Storage Point of Use Water Heater
When installing a small capacity water heater use flexible supply lines or flex lines as they are called. This will make installation easy and the unit will be easy to remove for cleaning.
Most small water heaters will have a 1/2 inch nipple to connect
to. A standard shut off valve under the sink is 3/8 inch. You would
need a flex line 1/2 inch X 3/8 inch (stainless steel is best).
The water heater nipple size will increase with capacity size. Buy a flex line to match your water heater and the shut off valve.
To installed a small water heater under a remote sink in your house you would remove the old supply line from the hot side shut-off valve. Screw the new flex line on to the shut-off valve and connect it to the cold side of the new water heater.
Next you would attach a flex line from the hot water outlet on the small water heater to the hot side of the faucet.
If you plan to install a unit somewhere other than under the sink add a nipple onto the plumbing pipe and connect the water heater with flex lines.
Be sure to fill the tank and run the water until all the air is out of the tank before you plug the unit up. Energizing the tank without water or air in the tank will damage the heating element
A point of use water heater will come with installation instruction.These water heaters are simple to install.