wackysue said:
I need to replace my hot water tank and the electric tankless hot water heaters are very appealing but different from what I have always grown up with. I need some help making the decision. I have a family of 5 to keep in hot water. Can you give me some advice?
Wackysue
Where do you live and how cold is the water supply in the winter?
5 GPM x 60 min per hour x 8.34 # per gallon x 70 degree temp rise / 3413 BTU/kWhr = 51.3 kiloWatts.
51,300 watts/240 Volts = 214 Amps. That's just for the water heater.
It is almost certainly more than the whole electrical service for your house.
Even 2.5 GPM for a minimal shower requires more than 100 Amps.
At 2.5 GPM it will take 16 minutes to put 40 gallons in a bathtub and cost about $1.00 for electricity at the rates in my part of the country.
You can adjust it for your own GPM requirements and temperature requirements.
I have been in showers supplied by electric instant water heaters in Europe where they are fairly common. I have NEVER had a satisfactory shower from one.