What To Consider Before Purchasing An Electric Tankless Water Heater

Unlike a gas tankless water heater, the electric models require no venting and have no combustion air requirements, however an electric tankless water heater must be hard wired and have minimum amperage requirements. The most important factor in installing an electric tankless water heater is ensuring you can meet the amperage requirements.  Some of the water heaters we carry such as the Ariston and AO Smith water brands are not tankless units but rather small tanks or mini-tanks that store a supply of hot water.

If you are needing to support more than one major water application at the same time such as 2 showers or a shower and a washing machine, then you should go with a gas tankless water heater as the electric models are not strong enough to support that type of water flow.

Lastly, please review the electrical requirements for each unit. All the Powerstar units require a 240 Volts and a minimum of 50 amps.  The larger units such as the AE125 require a minimum electrical service of 200 amps.  Please ensure that you have adequate electrical capacity to operate these units.

Electric Tankless Requirements

PowerStar AE115 – can support one major hot water application (i.e. shower) at a time in a warm environment.  To see where the AE115 can be used reference our climate map.  This model has two heating elements and each requires its own 40 amp breaker, so the AE115 requires 2 separate 40 amp breakers and a total minimum electrical service of 150 amps.

PowerStar AE125 – can support one major hot water application (i.e. shower) at a time in warm and cold environments.  This model has three heating elements and each requires its own 40 amp breaker, so the AE125 requires 3 separate 40 amp breakers and a total minimum electrical service of 200 amps.

Stiebel Tempra 24 – provides up to 4.10 gallons per minute (40 degree temp rise) for water usage at 105° F: 2 sinks or 1 shower.  Requires 2 independent 240V AC circuits protected by 2 separate and independent 60 amp double pole breakers. Minimum recommended electrical service is 180 amps.

Stiebel Tempra 36 - delivers up to 6.10 gallons per minute (40 degree temp rise) for water usage at 105° F: 2 showers & 1 sink.  Requires 3 independent 240V AC circuits protected by 3 separate and independent 60 amp double pole breakers. Minimum recommended electrical service is 300 amps.

Additional Information on Tankless Water Heaters? 

• What factors to consider when purchasing a tankless water heater?
• Important facts about natural gas and propane tankless water heaters?
• How does a tankless water heater work?