Water Heater Elements, Can I Make This Replacement?

[Bill]

Please bear with me, this explanation man take some time.

I purchased a water heater from a large retailer. After it was installed, I read the owners manual and found out the recovery rate was not 25 gal/hr as stated when it was sold, but 17 gal/hr. It was spec'd out incorrectly by the retailer. The retailer has offered me a really great incentive to keep the water heater. The water heater came with two 3800 watt elements. The water heater it replaced was on a 220 line with 12 guage and a 20 amp breaker and had two 4500 watt elements. I live in a warm climate and the two 3800 watt elements are fine in the summer, but I'm not certain about the winter months. I'm just wondering if I might be able to replace the two 3800 watt elements with two 4500 watt elements if I need the extra heating in the future? At the price I'm getting the heater and installation, I'd still be way ahead if I replaced the elements.

Bill

[Bill]

Some additional information. On the new water heater, the bottom element is dual wattage 3800/5500. I'd have to upgrade my electrical service to run it at 5500 watts. I'm not sure if this matters, but it might lend some clue about the water heater handling dual 4500 watt elements.

[Speedy Jim]

OK, I'll weigh in on this.

Your old heater has 4500W elements and has branch ckt conductors of #12. Right? Only one element runs at a time. So, 4500 / 240V = 18.75 Amps

For continuous loads, such as this, the 20A ckt can only be loaded to 80% of rating = 16 Amps. The #12 conductors are inadequate (IMHO). Run #10 and use a 30 Amp CB.

I assume the new heater has a dual-rated element on the bottom to provide faster heting from a cold start. 5500 / 240V = 22.9 Amps. The 30 Amp ckt, which you would need anyway, will support (30 x 80%) 24 Amps so it would be adequate for the new water heater without altering anything in the heater.

Jim

[RBM]

Water heater elements can be replaced easily enough although some require a large wrench. First of all the 4500 watt unit that you had was wired incorrectly as by NEC it requires a thirty amp circuit, not 20 amp. The current unit you have can be run on a 20 amp circuit if used at 3800 watts, but if you wanted to use the higher wattage, you'd need to run the 30 amp circuit as well