Replacing 2 50 Gallon Electric Water Heaters (3 bath house)

[kamiller42]

The water heaters in my house in north Texas are the originals, installed in 2004. I noticed one with a slight trail of moist rust coming from behind the temperature panel at the bottom of the heater. I figure it's getting close to time to replace.

There are 2 50 gallon GE electric water heaters plumbed in series in the attic. (There is no gas to the house.) There is a recirculation pump to get hot water to the far side of house. Otherwise, it's a 3 or 4 minute wait to take a shower.

What is the best combination of water heaters should I use for my 4 bedroom, 3 full bath house?
a) Two standard electrics.
b) A tankless & an electric
c) Two heat pump heaters
d) One standard & one heat pump
e) Entirely tankless
f) A single 80 gallon
g) Something else

Should they continue to be run in series? Would parallel be better?

Thank you for your opinion & help.

 

[Fitter30]

Series piped the first heater collects most of the minerals plus the stored water doesn't add up to 100 hot gallons. Parallel get more stored hot water both get the same amount of minerals. Need to add up total usage in gpm that is normally used to size a tankless and coldest incoming water temp. Need to look at some utube videos about tankless. Hp heaters have the room for their footprint and cubic feet of space to make them work properly. Then compare the two 50 to a 80.

 

[Sponsor]

 

[WorthFlorida]

Electric tankless takes a lot of power to meet demand. There are charts for inlet water temperature vs outlet temperature plus flow rate. Most will need three circuits for three heaters and a larger wire than 10 gauge may be needed. Your electric panel may not have the capacity.

Hybrids are complex. It's a air conditioner wrapped around a standard electric water heater with an electronic control board. If the AC part goes the entire WH has to be replaced. In Hybrid mode only, it may not meet hot water demands. When set for both, the electric elements will kick to meet the demand. I've read on this forum some control boards are no longer avaialble. If under warranty the whole water heater will need to be replaced.

Because it is attic space changing one out is not an easy task as if it was in the garage. The old standard electric, tired and true has a long life, only for parts (2 elements and 2 thermostats). Since 2010 energy bill, the electrics insulation greatly increases so dimension wise they are a few inches larger. An empty tank can be easily handled by one or two guys to get it in the attic space.

I just replaced my WH, garage installed, with a 50 gallon standard WH. I would go with a 50 gallon standard heater with a Cash Acme Tank Booster (or any other thermostatic mixing valve). Set the WH heater to 140º or higher. The Tank booster mixes the hot with cold for a 120º water to the fixtures. It's equivalent to 90-100 gallon water heater. This model has a connection for a circulator.

https://www.supplyhouse.com/Cash-Acme-24644-Tank-Booster-Pro-w-Braided-Hose-Temperature-Gauge

https://www.southernpipe.com/ASSETS/DOCUMENTS/CMS/EN/SKB24644_Specification_Sheet.pdf

I installed one at my son's house along with a new WH. Three baths with two teenage daughters plus the wife. Because of the height, there was no room for the temperature gauge. A standard or short height WH would have been better. You do need to add an expansion tank unless your on a well.

 

[kamiller42]

Series piped the first heater collects most of the minerals plus the stored water doesn't add up to 100 hot gallons. Parallel get more stored hot water both get the same amount of minerals. Need to add up total usage in gpm that is normally used to size a tankless and coldest incoming water temp. Need to look at some utube videos about tankless. Hp heaters have the room for their footprint and cubic feet of space to make them work properly. Then compare the two 50 to a 80.

Correct on the series. It's the first heater in series that has the small leak.

My attic has tons of space. No issue with space. Getting through the attic door is biggest restriction. Standard drop down stairs door.

What is your opinion of 2 40G's in parallel vs 1 80G?

 

[kamiller42]

Electric tankless takes a lot of power to meet demand. There are charts for inlet water temperature vs outlet temperature plus flow rate. Most will need three circuits for three heaters and a larger wire than 10 gauge may be needed. Your electric panel may not have the capacity.

Hybrids are complex. It's a air conditioner wrapped around a standard electric water heater with an electronic control board. If the AC part goes the entire WH has to be replaced. In Hybrid mode only, it may not meet hot water demands. When set for both, the electric elements will kick to meet the demand. I've read on this forum some control boards are no longer avaialble. If under warranty the whole water heater will need to be replaced.

Because it is attic space changing one out is not an easy task as if it was in the garage. The old standard electric, tired and true has a long life, only for parts (2 elements and 2 thermostats). Since 2010 energy bill, the electrics insulation greatly increases so dimension wise they are a few inches larger. An empty tank can be easily handled by one or two guys to get it in the attic space.

I just replaced my WH, garage installed, with a 50 gallon standard WH. I would go with a 50 gallon standard heater with a Cash Acme Tank Booster (or any other thermostatic mixing valve). Set the WH heater to 140º or higher. The Tank booster mixes the hot with cold for a 120º water to the fixtures. It's equivalent to 90-100 gallon water heater. This model has a connection for a circulator.

https://www.supplyhouse.com/Cash-Acme-24644-Tank-Booster-Pro-w-Braided-Hose-Temperature-Gauge

https://www.southernpipe.com/ASSETS/DOCUMENTS/CMS/EN/SKB24644_Specification_Sheet.pdf

I installed one at my son's house along with a new WH. Three baths with two teenage daughters plus the wife. Because of the height, there was no room for the temperature gauge. A standard or short height WH would have been better. You do need to add an expansion tank unless your on a well.

View attachment 91860

My attic has lots of space. It is surprising the AC head couldn't be replaced without replacing whole tank. I thought heat pump WH would be pretty good for me since heaters in attic in Texas.

I saw one reviewer mentioning thermostatic mixing valve. Nice way to boost capacity.

Since the 2010 bill increased insulation in WH's, is wrapping no longer needed? I wrapped mine.

You have the Rheem. Rheem sells the Performance Platinum in the stores and Professional Prestige to wholesale & plumbers. Any advantages or disadvantages to each?

 

[WorthFlorida]

When you get into the higher priced WH's, it is usually electronics are added and it just becomes another source for failure. Warranty maybe 9 or 12 years but unless you know exactly how the tanks were manufactured, I think all your buying is warranty, not necessarily better quality. Electronic control usually is an attempt to control power consumption, some with WiFi so you can shut it down remotely such as for a vacation mode. I usually just power off the heater at the panel. A Wifi controlled WH might be good for a remote cabin or lake house.

Wrapping is no longer needed. Like Florida, the attics get pretty hot, therefore, trying to maintain 120º water in a 110º attic, there is virtually no gain. If the WH has electronic's, a wrap can increase heat on the components and shorten it's life. Some water heaters come with about a four foot length of pipe insulation since in certain parts of the country is required by code.

Another though on two tanks in parallel, getting equal water flow from both thanks can be difficult. Pipe location and directions makes a difference. Essentially one tanks plumbing needs to be nearly a mirror image of the other. Plenty of info on line if you want to go that route.

Another factor going on is insurance companies and now it looks like they're doing it with roofs. I had to replace my 15 year old WH before the renewal date of my home owners insurance policy. The WH is in the garage, no chance that it could do damage and absolutely no signs of corrosion or leaking. When you do change your water heater takes pictures of the label and inform the insurance company. Do change the drip pan. Old plastic ones get brittle and can crack.

 

[Jeff H Young]

I wonder what the differace is on a lot of parts including water heaters , The million dollar question I know that I got stuck paing 32 dollars for 1 inch l and right coupling this week at my freindly plumbing supply where I have an account instead of 2.17 from my online source or 9 dollars for a high quality domestic maker online both include shipping Im not sure if the 32 dollar one is made in USA . Some product is better at one place than another but Im not convinced that water heaters or anything is allways better at a professional warehouse over a big box , local hardware , or numerous online sources .
With specific referance to water heaters I think its sort of a toss up and think there could be some value getting the "pro series"
differance in price if only 10 percent or so might be worth the extra cost if its cheaper at the pluming supply go there dont pay more at home depot

 

[Sylvan]

Have you considered Propane as electric takes for ever to heat

 

[kamiller42]

Have you considered Propane as electric takes for ever to heat

Wouldn't I have to install a propane tank in the attic? Is that safe?

 

[kamiller42]

When you get into the higher priced WH's, it is usually electronics are added and it just becomes another source for failure. Warranty maybe 9 or 12 years but unless you know exactly how the tanks were manufactured, I think all your buying is warranty, not necessarily better quality. Electronic control usually is an attempt to control power consumption, some with WiFi so you can shut it down remotely such as for a vacation mode. I usually just power off the heater at the panel. A Wifi controlled WH might be good for a remote cabin or lake house.

Wrapping is no longer needed. Like Florida, the attics get pretty hot, therefore, trying to maintain 120º water in a 110º attic, there is virtually no gain. If the WH has electronic's, a wrap can increase heat on the components and shorten it's life. Some water heaters come with about a four foot length of pipe insulation since in certain parts of the country is required by code.

Another though on two tanks in parallel, getting equal water flow from both thanks can be difficult. Pipe location and directions makes a difference. Essentially one tanks plumbing needs to be nearly a mirror image of the other. Plenty of info on line if you want to go that route.

Another factor going on is insurance companies and now it looks like they're doing it with roofs. I had to replace my 15 year old WH before the renewal date of my home owners insurance policy. The WH is in the garage, no chance that it could do damage and absolutely no signs of corrosion or leaking. When you do change your water heater takes pictures of the label and inform the insurance company. Do change the drip pan. Old plastic ones get brittle and can crack.

The more I look at this, the more it looks like I am going your route. Any WH size above 50G will likely not fit through my attic door. "Misses by THAT much." Approx 23" is max width.

The thermo mixing valve sounds like a great idea. The WH heater will work harder though. Energy wise, it takes more to run, but I would need only 1 WH rather than two. What is the lifespan on the tank booster? One guy's review said the Cash Acme goes out every "few years."

Many WH's are 4500W. 5500W is an option. Is that better or is it overkill?

I notice many sellers on Facebook Marketplace sell WHs for nearly half the price of places like Home Depot. Some look like distro houses. Safe to buy from? I figure they are pulling from home builder supply or have overstock.

 

[Master Plumber Mark]

You should just put in another 2 50 electric water heaters and be happy...
They have worked well since 2004 so what more can you ask of them??..

Also, If you only have 2 bathrooms you can probably go with 2 40 gallon units .

2 50 gallon heaters is a whole lot of hot water , I assume you have a huge home...

Just hook them up in series like they originally were and be sure to install
new pans under the water heaters and some new thermal expansion tanks too....

Stay away from hybrid heaters for an attic situation.....
STAY AWAY from an electric tankless type of water heater...
they are nothing but trouble

Just do the simple easy thing and stop trying to overthink things...
With the heaters being in the attic they are, for at least 6 months,
in a very hot environment and are actually being heated just from the intense heat
and you are not going to gain anything installing fancy things that wont save a dime
in the attic.. ...

keep it simple.

 

[WorthFlorida]

I bought mine and one for my church from Ferguson, AO Smith Proline 50 gallon. You'll need a tall version because of width. My son bought one at Home Depot. Rheem, 50 gallon tall. 5500 watt element WH gets expensive at Ferguson and it may eliminate the need for a tank booster. The 5500 watt units have a faster recovery time. It really depends on your hot water demand. I always had 50 gallon 4500 watt heater even when my boys were teenagers. Now retire with the just the wife and I 50 gallon is more than needed. If you have teenage daughters, no chance, get all the heat you can muster.

I do not know what the lifespan is for the Cash Acme units. There are other thermostatic mixing valves on the market but the Cash Acme makes it simple. You can install a 5500 watt unit and if the water demand exceeds the WH, the mixing valve can be added later. To reduce the demand for HW is mostly with shower heads. They cannot be more than 2.5 gallons per minute at 60PSI but most are far less to meet codes for water reduction use.

Do not buy one online. Warranty could be a problem and if one should be bad, where do you do an exchange? I do like the AO Smith Proline if your looking for quality. Bradford White seems to be the best but Ferguson will not sell you one since you need to be a licensed plumber but they are available on line.

The theory on two tanks either parallel or in series is an never ending debate.

 

[kamiller42]

You should just put in another 2 50 electric water heaters and be happy...
They have worked well since 2004 so what more can you ask of them??..

Also, If you only have 2 bathrooms you can probably go with 2 40 gallon units .

2 50 gallon heaters is a whole lot of hot water , I assume you have a huge home...

Just hook them up in series like they originally were and be sure to install
new pans under the water heaters and some new thermal expansion tanks too....

Stay away from hybrid heaters for an attic situation.....
STAY AWAY from an electric tankless type of water heater...
they are nothing but trouble

Just do the simple easy thing and stop trying to overthink things...
With the heaters being in the attic they are, for at least 6 months,
in a very hot environment and are actually being heated just from the intense heat
and you are not going to gain anything installing fancy things that wont save a dime
in the attic.. ...

keep it simple.

The WHs were installed in 2004 and put into service in 2005. I'm the second home owner.

I have 3 full baths. I am guessing part of the reason for 2 50Gs is the full baths have those deep jet tubs.

I was thinking the attic would be the optimal place for a hybrid WH because of all the hot air it can pull in. And if not going with a hybrid WH, a standard 50G w/mixing valve sounds like an interesting compromise because it drops one WH.

100G is a lot of water, and I'm powering 2 WHs all the time even if most days, if not all, 50G is enough.

 

[Master Plumber Mark]

The WHs were installed in 2004 and put into service in 2005. I'm the second home owner.

I have 3 full baths. I am guessing part of the reason for 2 50Gs is the full baths have those deep jet tubs.

I was thinking the attic would be the optimal place for a hybrid WH because of all the hot air it can pull in. And if not going with a hybrid WH, a standard 50G w/mixing valve sounds like an interesting compromise because it drops one WH.

100G is a lot of water, and I'm powering 2 WHs all the time even if most days, if not all, 50G is enough.

it all depends on whether you actually use the whirlpool tubs or not.....
if you do then you would be wise to stay with 2 50 gallon electric heaters in series....
in reality you can always set them up with the final one in series to be set on hot
and the first one could be set on low or medium as a pre-heating unit......
Or you could make the first heater only a 40 gallon unit to pre-heat everything

Also, you could even lay a 100 foot roll of 3/4 pex
up stairs in the attic before it goes into the heaters and allow the
attic to pre-heat the water passively... I would probably do that myself if I lived in Texas..
----now thats the dirt cheap way to save money..just lay the 100 ft roll of pex in a washing machine pan
to collect any condensation that might happen and you are good

I have been told that The hybred heaters are really not meant to be installed in extremely hot areas
and the stress on the circuit boards and other computer components
will burn them out fast....

Now if you have a "throbbing hard on" to get a hybred heater and find out for yourself
dont let me stop you.....

 

[kamiller42]

it all depends on whether you actually use the whirlpool tubs or not.....
if you do then you would be wise to stay with 2 50 gallon electric heaters in series....
in reality you can always set them up with the final one in series to be set on hot
and the first one could be set on low or medium as a pre-heating unit......
Or you could make the first heater only a 40 gallon unit to pre-heat everything

Also, you could even lay a 100 foot roll of 3/4 pex
up stairs in the attic before it goes into the heaters and allow the
attic to pre-heat the water passively... I would probably do that myself if I lived in Texas..
----now thats the dirt cheap way to save money..just lay the 100 ft roll of pex in a washing machine pan
to collect any condensation that might happen and you are good

I have been told that The hybred heaters are really not meant to be installed in extremely hot areas
and the stress on the circuit boards and other computer components
will burn them out fast....

Now if you have a "throbbing hard on" to get a hybred heater and find out for yourself
dont let me stop you.....

The pex is an interesting idea. My only concern is when we get those hard freezes, like 18 degrees for 3 days. It'll freeze up. I guess the pex can be wrapped in insulation or keep a blanket on it. Yes?

 

[Jeff H Young]

it all depends on whether you actually use the whirlpool tubs or not.....
if you do then you would be wise to stay with 2 50 gallon electric heaters in series....
in reality you can always set them up with the final one in series to be set on hot
and the first one could be set on low or medium as a pre-heating unit......
Or you could make the first heater only a 40 gallon unit to pre-heat everything

Also, you could even lay a 100 foot roll of 3/4 pex
up stairs in the attic before it goes into the heaters and allow the
attic to pre-heat the water passively... I would probably do that myself if I lived in Texas..
----now thats the dirt cheap way to save money..just lay the 100 ft roll of pex in a washing machine pan
to collect any condensation that might happen and you are good

I have been told that The hybred heaters are really not meant to be installed in extremely hot areas
and the stress on the circuit boards and other computer components
will burn them out fast....

Now if you have a "throbbing hard on" to get a hybred heater and find out for yourself
dont let me stop you.....

But only if its throbing LOL!!

 

[Master Plumber Mark]

The pex is an interesting idea. My only concern is when we get those hard freezes, like 18 degrees for 3 days. It'll freeze up. I guess the pex can be wrapped in insulation or keep a blanket on it. Yes?

Your heaters are being passivly heated all the time up in that attic except for the cold winters

but if you are in Texas that should not be a concern or they would not have put the water heaters up in
the attic in the first place.... I guess the water lines are insulated in the attic??

I would suggest keeping the water slowly running if it actually gets down that cold..... or you would have issues with or
without the pex coil....

Also if you use Wirsbo Aquapex it will freeze but it will not break.......

 

[Master Plumber Mark]

But only if its throbing LOL!!

NEVER get in the way of a guy with a "Throbbing Hard On" to do something stupid..
because they will never thank you for helping them stay out of trouble..

Just ask my brother-in-law who is on his working on his third divorce......lol
they got to learn for themselves... .