Tank less hot water heaters If you are thinking about replacing your standard tank type gas water heater or your tank type electric water heater with a tank less water heater also known as an on demand water heater or a point of use hot water heater, there are a few things to think about first, for example.
If you have hard water, the tubes inside your new tank less water heater will become clogged and greatly restrict the flow of hot water from your on demand water heater to your faucets. Also because of the design of the tank less water heaters there is a flow restriction on the hot water side of your water supply, meaning you may get less water flow to your faucets on the hot side because of a needed flow restrictor installed on the water line just before your on demand hot water heater.
The flow restrictor is necessary to prevent the water from flowing through your new tank less water heater too fast, If the water goes through your on demand water heater too fast in will not heat the water and you will have warm water or cold water coming from your on demand hot water heater.
Other problems I have come across, when more than two faucets are being used at the same time, the hot water flow from the tank less water heater is very low to each of the faucets.
This is because of the limited flow through the on demand water heater in the first place.
Point of use hot water heaters are small water heaters that supply hot water to 1 or 2 sinks at a time. Point of use water heaters should only be used for small jobs like washing hands. A point of use hot water heater should not be used to fill a bathtub or and high volume use fixture.
Some complaints I have received with some tankless hot water heaters were, (this only applies to some, not all on demand water heaters) if you are only using one faucet, the on demand water heater will not fire and you will not get any hot water, this is because there is not enough water flow through the tankless water heater to cause it to fire, opening another faucet at the same time will cause the on demand water heater to fire but this is a waste of water and energy. If you have these problems contact the manufacturer to see if they have a replacement part to correct the problem.