Seeking Advice: Hot Water Supply

[rustic_philosopher]

So we have a large tub in our master bath and 50G electric tank heater that supplies the master bath, master shower and guest bath. I don't know the exact size of the tub but its large and the 50G is not able to fill it.

Points of note:

1. We are very rural, only have electric so gas is not a practical option in the house.
2. Plumbing is all PEX
3. The space for the water heater in question is basically 24"x24"
4. We are on a well that has a iron filter and water softener. Even so, there is still a decent amount of minerals in the water.

Options I have looked at / debating:

1. Increase the temp on the water heater and have a thermostatic mixer valve installed to try and get the 50G to behave more like a 70G which should suffice for filling the tub I think.
2. Add a tankless heater with input coming from the tank heater as a way to supplement the hot water when the tank water runs cold.
3. Perform major remodel work in the utility room where the water heater is to allow for a larger space so that I can install a larger tank.

Concerns / Questions:

1. Per option #1, my understanding is that increasing the temp on the tank heater shortens the life. Is there any idea of how much life is lost by doing this and are there any tanks / brands that are better suited to running hotter?
2. Per options #2, my understanding is that electric tankless should be avoided but in this use case of supplementing hot / warm water from the tank would an electric be fine? As a side note - this option is kind of a pain as it would require a lot of electrical work to add support for another 240v and my panels are almost full.
3. I initially leaned toward this idea from a simplicity aspect but my concern is losing space in the long run (tl;dr - we would have to lose some shelf space) to account for a now problem. From what I can tell, tankless is the future. Personally I think its still a little early given they only seem viable on gas but some day when electric is viable, I could see even on well (with additional water quality treatment) just having to switch over to more efficient tankless systems. When that days comes, the work to expand the tank area would be wasted as the equipment won't have the same footprint.

I am leaning toward option #1 mainly due to concern #3 I list in regards to future tankless use and space usage - but I know that I don't know what I don't know so here I am palms up asking for help

So does the stuff I call out make sense, am I going in the right direction or is there a solution that makes more sense that I am not seeing? Appreciate any feedback people can share.

 

[MicEd69]

You don't say what temperature you have your water heater set. Do you have small children in your home or that visit often? Do you have a thermostatic mixing valve on your tub?

Before changing out water heaters, or adding water heaters, the first approach is obviously to increase the temperature of the existing water heater. And if that didn't work, I would find the space somewhere and add a second regular electric water heater before I would ever consider a tankless electric water heater. But that is my opinion and others will probably disagree.

 

[havasu]

I agree. An electric tankless water heater is not worth the trouble to install.

 

[rustic_philosopher]

You don't say what temperature you have your water heater set. Do you have small children in your home or that visit often? Do you have a thermostatic mixing valve on your tub?

Before changing out water heaters, or adding water heaters, the first approach is obviously to increase the temperature of the existing water heater. And if that didn't work, I would find the space somewhere and add a second regular electric water heater before I would ever consider a tankless electric water heater. But that is my opinion and others will probably disagree.

• This may sound stupid (it does actually as I write it out) but I am unsure on the hot water temp as the tank has no real marking on the dial that I saw. I need to take a thermometer to the water in the nearby bathroom to check.
• I have an 8 month old but this water heater in question and tub is tied solely to the master bath and guest bath. The kids bath is on another tank but regardless I was thinking of putting the thermostatic mixer on there to make sure the water was still safe if that makes sense.
• I don't really have any space for another full size heater practically. I could makybe work in a tankless in the same place as the regular tank but as you say I was interested in avoiding that if at all possible.

In terms of increasing the temp on the tank though - does that shorten the life and are there tanks / brands that are better rated to operate in that manner?

 

[rustic_philosopher]

I agree. An electric tankless water heater is not worth the trouble to install.

You agree with just upping the temp? If so, do you have any opinion on tank life and brands / models that support that operational mode?

 

[lmcancu]

Have you checked whether you have burned out elements in your existing water heater? What is the wattage rating on it? Check first whether the water heater is actually working properly. If not, repair and replace it. I don't know how big your tub is but a 50G heater should be more than sufficient

 

[havasu]

You agree with just upping the temp? If so, do you have any opinion on tank life and brands / models that support that operational mode?

Electric W/H's in general suck. Get NG if at all possible.

 

[rustic_philosopher]

Have you checked whether you have burned out elements in your existing water heater? What is the wattage rating on it? Check first whether the water heater is actually working properly. If not, repair and replace it. I don't know how big your tub is but a 50G heater should be more than sufficient

I think its working correctly as we do have hot water in general - just only about enough for 2/3 of the tub (it is a pretty deep soaking tub).

I am still curious though as to the lifespan concern with the water heaters though and if any brands are suited to running hotter. I mean, maybe I am misunderstanding that but I thought it was a concern with higher temps?

 

[rustic_philosopher]

Electric W/H's in general suck. Get NG if at all possible.

NG isn't an option, only electric where I am at.

 

[havasu]

I figured as much. A tanked electric W/H has time to get hot, but have yet to see an electric tankless W/H that a customer is satisfied with.

 

[Mitchell-DIY-Guy]

NG isn't an option, only electric where I am at.

But like many people in rural areas you COULD go with propane.

If the life of the tank is shortened it’s probably the heating elements that MAY fail prematurely. Who cares? They are cheap and easy to replace. Learn how to diagnose element failures and replacement. Keep spares on hand.

A standard tub holds 50-70 gallons. A soaker tub even more than that. That’s ALL your hot water from a tankful.

Electric water heaters have slow recovery…

 

[rustic_philosopher]

I figured as much. A tanked electric W/H has time to get hot, but have yet to see an electric tankless W/H that a customer is satisfied with.

Well to be clear, I don't think the plan is to use a tankless right - more to just use an electric tank heater but jack the temp up right? Everything I have read agrees with your take on tankless electric so I would be very hesitant.

 

[rustic_philosopher]

But like many people in rural areas you COULD go with propane.

If the life of the tank is shortened it’s probably the heating elements that MAY fail prematurely. Who cares? They are cheap and easy to replace. Learn how to diagnose element failures and replacement. Keep spares on hand.

A standard tub holds 50-70 gallons. A soaker tub even more than that. That’s ALL your hot water from a tankful.

Electric water heaters have slow recovery…

1. I can't practically go with propane as A) I don't have a reasonable spot for a propane tank install outside with tear out and B) don't have the means to run gas lines into the house which would be a very major project. It would be more practical and cheaper to remodel the water heater closet area to support a 70 or 80 gallon electric than it would be to setup gas infrastructure at the house.
2. Ok, fair enough on the cheaper replacement of a tank heater but the thing I keep trying to understand is A) if anyone with plumbing expertise has any knowledge on how a higher temp impacts the life of a tank and B) do folks have any brand knowledge based on experience as professional plumbers around tank brands that tolerate higher temps better from a longevity perspective.
3. "A standard tub holds 50-70 gallons. A soaker tub even more than that. That’s ALL your hot water from a tankful." - I don't follow where your driving here? I mean I agree and it describes the problem I am trying to solve but I am not following the context I guess.

 

[Mitchell-DIY-Guy]

What I meant by the capacity of the tub is that you’re trying to solve a problem that really is not going to be solved electrically. You need too much hot water… and you can’t generate enough hot water with an electric tank to keep a tub hot enough or full enough. Look at ANY “first hour” rating, then the recovery rate… you may get 61 gallons in the first hour and 21 gallons each subsequent hour. I don’t think a 50 gallon electric water heater and a tub work well together…

I have a client now who lives in an apartment who is trying to do what you are trying to do. Basically, she heats water in pots on her stove because filling her tub drains the tank…and by the time the tank recovers the tub is already cold. She has no viable solution. She refuses to take showers.

In addition to the potential scald factor, operating the electric water heater at something beyond what the manufacturer recommends probably isn’t a good idea.

Good luck!

 

[havasu]

Bottom line is that you will need to up the temp on the electric tanked water heater and as they say, "that's all ya got Captain", or you increase the size of your electric water heater, so there is more stand by hot water.

Will increasing the temperature on a tanked electric water heater decrease its lifespan? Maybe, but just as a car....the more you drive it, the quicker it will break down.

 

[MicEd69]

As havasu said, you are stuck with electric, so crank it up to 140 and see if you can fill your tub with hot water. And as Mitchell-DIY-Guy said, the primary issue of setting the water temperature higher is failed elements. They are readily available, easy to change, and you can even get universal titanium heating elements that will likely fit your current water heater, which may help increase the life the elements.

IMHO, as long as you stick with a major brand, Rheem, AO Smith, Bradford White, etc., you will not see much difference in the life of the elements.

 

[rustic_philosopher]

Thanks for the feedback folks, much appreciated. I guess I will look closer at changing the element as needed and try and get stuff to make that painless as possible.

Any thoughts on a thermostatic mixer valve? My understanding is that this is kind of a must have for this approach given it will make the water unsafe in terms of temp. I know nothing about them beyond the brochure description and being told I need one.

 

[GReynolds929]

Thermostatic Mixing valve is the safest and best way to do this. Crank the tank to 150-160 and set the mixing valve to 120. When water is heated whatever is in solution falls out of solution, so there will be more scale and mineral buildup with higher temps. Flush the heater regularly and be ready to change elements sooner than normal. Tank life may be shortened, it may not. Doesn't seem like there's much choice either way.