I have a 460v 3 phase water heater I need to replace, I want to go back with a 208v 1 phase. The question is, Are there any drawbacks as far as utility cost to operate the 208v 1 phase vs the 460v 3 phase?

No, just the recovery rate is likely less with the 208V unit.

You pay for wattage so check to see what the wattage is between the units.

If I may ask, why would you bother to run a new circuit for the 208V unit when you already have the wiring in place for the 460V?

No, just the recovery rate is likely less with the 208V unit.

You pay for wattage so check to see what the wattage is between the units.




If I may ask, why would you bother to run a new circuit for the 208V unit when you already have the wiring in place for the 460V?


The cost of the 3 phase water heaters is really expensive, thousands vs hundreds. We no longer need a heater the size of the old one and the heater is close to the electrical panel, so the cost of running a new circuit is minimal. This is in a 4 story office building and only serves the restrooms (8) for hand washing, there is also a recirculating pump we will continue to use. The old one is 18 kw and I would think the new one would be less than that, probably quite a bit. I know we are billed by kw usage but in a brief conversation with my electrician, he mentioned the 208v may be less efficient but he may have been referring to recovery time. Thanks for your response.

Well then your idea makes a huge amount of sense. And you are right, a new smaller unit will likely be only 6000/4500/3380 watts, as opposed to 18,000(!! ).