Which electric WH to buy?

[Mike141]

currently have an 80gal AO Smith in need of replacing for a family of 4 with 2.5 baths in northeast, WH in basement. Wondering if I go down to a 50 hybrid I’ll have enough hot water. We shower at different times of the day, tend to do regular amount of laundry. My state is offering a nice rebate now on these 50gal hybrids which would bring the cost of it under $600. If I stick with 80, it would be regular electric, I don’t want to do the 80 hybrid model, too much $$$. My question is, are these AO Smith hybrid models good or just making a simple procedure too complicated and introducing too many electronics?

 

[Master Plumber Mark]

Their are some good choices for you out there....

a 55 gallon elctric is available from Rheem, and the all others too.... that size seems to suffice to replace the big 80.....
and its only being slightly higher in $$ than a 50 in cost and you turn up the t-stats 7 degrees and everyone is happy and no one in the house will know you downsized to a 55 unless you open your mouth and tell them......

Rheem also makes Marathon life time heaters in 75 + 85 which is much more expensve but if you
have a whirlpool tub then it would be wise to think about getting that size...
the lifetime feature is sort of nice too

In my honest opinion, all the hybrids are trouble,,, way
too much technology just to heat up water and too much can go
wrong with them.... very few plumbers can actually service one .....
and I never have or will attempt it......

I see them all the time at the junk yard by the plumbing supply house...
they throw the whole thing away when one leaks and nothing is saved off them.....
rather wasteful but impossible to do anything with the compressor except strip the copper off of it..

I think that this one is a 75 Marathon from Rheem.....

 

[Sponsor]

 

[Phog]

Hi Mike 141, here are a couple things to think about as you consider downsizing the tank capacity.

1. What is the lowest incoming cold water temperature you see during the year? If you see 33F cold water in the dead of winter this means you need proportionally more hot water mixed in with the cold to give you the same warm shower. Therefore your hot water tank will deplete that much faster. In southern states you might get by with a 40 gallon tank with reserve to spare, while the exact same water usage with a 50 gallon tank in Northern NY or Northern NE might be inadequate.

2. Do you have a larger soaker tub anywhere in the house that you will ever want to fill up? If so you need to size the tank such that it is roughly the capacity in gallons of the tub. Or else your tub will be useless.

3. Finally regarding cost efficiency. With 4 people in a house, depending on the usage profile you might or might not see a big benefit from the hybrid unit. The big efficiency gain comes from times when only the heat pump is running, but recovery time in this mode after a draw is slow. If you then draw more hot water before the heat pump has a chance to do its job, the electric element will turn on & the unit will essentially become the same cost to operate as a "normal" (non-hybrid) electric tank. Since you're getting a big rebate which more than offsets the upfront cost difference, I don't think this matters much to your situation. But at least it's good to know.

4. You can also increase the usable hot water output of any tank by increasing the thermostat setting and installing a thermostatic mixing valve.

 

[Mike141]

Thanks for all the info here...I think I’m just going to stick with the 80 AO Smith electric (same as I have now). Since new regulations they say that this model is now considered commercial....does that mean anything different than the model I currently have that was made in 2012 or just a classification?

 

[Jadnashua]

Many of them now have more insulation in them, but other than that, not a huge amount.