The disadvantage of on-demand or instant hot water heaters is the upfront cost. Tankless units make up for the upfront cost by twice the longevity and less utility costs. Be careful not to be a sucker for plumbers selling cheap smaller units. They don’t produce enough hot water to serve most households. They’ll only do one faucet at a time. This is a problem if you want to shower while the dishwasher is running. For residential, we install medium-sized units. They will service several showers at a time.
Hot water heater manufacturers specify a life of about eight to 12 years for water heaters with tanks. Tankless water heaters last twice as long -- about 20 years.
Tankless water heaters cost most upfront but save on utility costs and last twice as long. A tankless water heater costs between $900 and $2,200 before installation.
Without installation costs, a hot water heater will costs between $500 and $1,400. This depends on the quality of the unit.