Boosting smaller tank or finding Commercial that fits?

[SteveNathan]

Time to replace our 21 year old tall skinny 80 gallon. Space is tight 24.5x24.5, and only "residential" tanks I see are to fat or only 50 gallon. I've read about the Tank boosters that have you raise temp to 140 or more and they mix cold to deliver back at 120. Seems like a tank life shortener to me. remaining options are pay more for a so-called "Commercial" (if I can find one that fits and is decent quality), or try the Rheem booster, which looks to me like it's essentially a third element.
Anyone have experience with the Rheem?
https://static.globalimageserver.co...2018/05/RHM4851_WaterBooster-Brochure_R31.pdf
I should mention that tankless is not an option. In a Condo building with no gas and insufficient electrical to be useable.

 

[Twowaxhack]

Just curious why you need so much hot water ?

50 gal wouldn’t work ? Big tub ?

 

[SteveNathan]

Big tub. My wife fills it twice a day, plus has allergies, so the washer is running most days. Throw in the dishwasher and my love of a good hot shower, and we're tapped out.

 

[Twowaxhack]

Stack two 40 low boy heaters on top of each other.

They’re 32” tall and 23” in diameter. Build a shelf 8” above the bottom heater to set the 2nd heater on.

Or use a 50 with the Rheem extender you posted. I’ve never installed one.

 

[Twowaxhack]

This one is 24.5” in diameter.

Jam it in there……..

https://www.homedepot.com/p/Richmon...lement-Electric-Water-Heater-S80U-1/202959691

 

[Mitchell-DIY-Guy]

Stack two 40 low boy heaters on top of each other.

They’re 32” tall and 23” in diameter. Build a shelf 8” above the bottom heater to set the 2nd heater on.

In a scenario like this, would you try to use both “plugged in” and heating, or use one as storage and the other to heat? May not be enough power available for both heating?

 

[wpns]

If you were going to kludge the plumbing to stack two short tanks together, you might as well kludge the electrical to do the same, in the same way the two heaters in a short tank can be wired to only allow one at a time to run.

 

[wpns]

The electric heater in a solar tank usually only heats the top half of the tank.

 

[Twowaxhack]

The electric heater in a solar tank usually only heats the top half of the tank.

You’re correct. But with that Rheem I believe it’s possible to modify it.

To the OP:

WPNS is correct but be aware that the water heater could be altered to operate as a normal water heater but you might have to order a few parts and add some wiring.

So straight out of the box it will not operate as a replacement double element heater. My mistake, sorry about that.

 

[Twowaxhack]

If you were going to kludge the plumbing to stack two short tanks together, you might as well kludge the electrical to do the same, in the same way the two heaters in a short tank can be wired to only allow one at a time to run.

It sure can be done but you’d probably have to do it yourself. I’ve done it before but I dont do it for the general public.

You replace the first heaters lower thermostat with an upper thermostat and add wiring from that thermostat to the next water heaters upper thermostat. You’d end up with 3 upper thermostats and one lower thermostat.

Then it’ll work like one big heater with 4 elements, non simultaneous operation.

 

[Twowaxhack]

If you have another closet available and access to the hot water piping, you could add another heater in series.

You’d need electrical 220 10 ga wire on a double pole 30 amp breaker to the 2nd heater.

Or buy this one and move on with life……
https://www.consumersplumbing.com/p...-commercial-water-heater-light-duty-eld80-tb/

 

[Twowaxhack]

A 4500 watt element takes an hour to raise the temperature of 27 gallons of water 70 degrees. @240 volts. You must de-rate the elements @220v or @208v.

Elements run non simultaneous, meaning only one heats at a time.

So It would take approximately 2 hours to heat a 50 gal. Tank from 60 degrees to 130 degrees.

If you had access to another 240v 30 amp circuit, you could convert a 50 gal electric to Simultaneous operation and both elements would run in unison. This would cut the time it takes to heat a 50 gal from 60 degrees to 130 degrees in approximately 1 hour.

You could improve this a little by installing 5500 watt elements knocking about 10 minutes off the total…..a tank would take approximately 50 minutes to raise the water temp 70 degrees.

This would cut your heating time down to an hour between full tanks in the winter. You’d have better performance when the incoming cold water temps improved in spring, summer, fall.


It comes down to how much money you want to spend and how much convenience you want.

However, completely depleting your tank is not good for it. It will cause premature failure. Getting hot then running completely cold causes condensation that will eat the tank from the outside in…..and it also puts stress on the welds from the expansion and contraction.

For these reasons you want to keep the tank warm rather than completely draining it of hot water

 

[Twowaxhack]

Right now with an 80 gal unit with 4500 watt elements non simultaneous operation it’s taking you approximately 3 hrs to heat 60 degree water to 130 degrees.

 

[Twowaxhack]

With a thermostat setting of 140 degrees ( yep it’s hot) and a cold water temp of 60 degrees and a bath water temp of 105 degrees……56% of your bath water will be hot water.

So, how much water does your wife run in the tub and how hot does she like it ?