Best Instantaneous Hot Water Heaters

An instantaneous hot water heater is a hot water heater that does not use a large tank to store the hot water. An instantaneous hot water heater, or tankless hot water heater, instantly heats the water up to the desired temperature as it flows through it. This is one of the advantages of an instantaneous hot water, it can continue to supply hot water as long as there is demand for it. With the best instantaneous hot water heaters you can fill up a large garden tub for a relaxing bath and their will still be hot water for others to shower or other appliances.

Instantaneous hot water heaters are also more efficient than the traditional hot water heater with a tank. Depending on the type of tanked water heater they are being compared to, the best instantaneous hot water heaters can be up to 50% more efficient. This would likely be going from an electric hot water heater with a tank to a instantaneous hot water heater that uses natural gas. Instantaneous hot water heaters can use natural gas, propane or electricity as their power source.

One of the primary criteria used to rate an instantaneous hot water heaters is the gallons per minute that it can raise a certain temperature. When making this comparison be sure to consider the same fuel type, don’t compare a natural gas unit with an electric unit.

The Best Instantaneous Hot Water Heaters

Manufacturer & Model GPM up 35 degrees Warranty Apx Cost
Rinnai RL94iP Propane 9.4 12 years $1100
Bosch ProTankless 940 ES LP 9.2 15 years $1200

I would rate either one of the two listed above as the best instantaneous hot water heaters. When I built my house nine years ago I put in a, now older, model of the Rinnai instantaneous hot water heater and there have been no functional issues with it. Really the only downside that has appeared with it is that when my boys shower they don’t run it hot enough to have it continue to sense the demand for hot water so would go cold. Now they just turn on the hot water at the sink while they shower.

These would be whole house instantaneous hot water heaters as oposed to a small hot water heater unit that fits under the sink. With this being the case there will still be some delay until the hot water makes it to the sink or shower, but once it’s there it will continue to come as long as it’s run.

Most instantaneous hot water heaters will require a professional to install them to meet requirements of the warranty. This might cost a little more at installation, but the fact that a tankless hot water heater will last a lot longer than a traditional hot water heater. They can last up to twenty years. The initial cost of the unit may also be a little more than a traditional hot water heater but the cost savings over the life of the instantaneous hot water heater will make up the different, and more.