When choosing a water heater, several options come in to play; space, connectivity and the overall need for hot water in the household. A tank water heater is great for the storage of hot water if the power goes out, and they have been used for decades. The tankless or instantaneous water heater is growing in popularity but the expense is holding the popularity back. I personally prefer an instant water heater for several reasons- space is an issue, a tank needs a 5x5 foot area of clear space for the overflow and drain, the thermostats need adjustment and regardless of the attempts to preserve hot water, it will eventually run out.
I bought a heavy duty in line water heater for the purpose of heating my house, taking long showers and doing the dishes all at the same time. Sure the initial investment was high, but my electric bill was reduced by twenty percent and there's not a huge metal monolith in my basement. The inline water heater can be installed by the homeowner and used immediately. The tank style has to be leveled, filled and adjusted while the unit heats water. The operative words are heats. The tank style is continuously running to maintain the selected temperature and when the tank is used for showers, it will spike the electric to keep up with the demand. An inline heater only uses electric when the hot water is needed.
I installed an inline heater for a client who always ran out of hot water for their commercial dishwasher. The tank style heater was re-routed to the bathrooms and the basic utility sinks. The client used both heaters for about a month but now has in line heaters attached to every sink in the facility. The space where the tank was is now a storage closet and the client saved over three hundred dollars on their power bill so far.
An in line electric water heater comes in a variety of sizes, rated by cubic feet per minute (CFM), and voltages 120 or 240. If you connect one to a guest bathroom sink, go with a low CFM low voltage unit. Go with a dual pole (240) volt high CFM if you want to use hot water in every area of your house.
Ultimately, only your preferred local plumbing expert can tell you which heater fit your needs best. If you need a water heater installation in Berkeley, CA, contact Albert Nahman Plumbing at (510) 843-6904.