I have an AO Smith 40 gal electric water heater. Model # ECT 40 200. My wife runs out of hot water in the shower after about 15 minutes in the winter. I have replaced upper and lower elements and thermostats, the anode rod, and flushed out the WH. Still no improvement. We don't have any kids yet, and live in a 3 bed 2 bath house built in 2014.

Anyone have any ideas why I continue to have this issue?

My follow up question is, are electric tankless water heaters any good? Anyone have good experience?

Is this a new/increasing problem or just something that happens every winter? What is the temperature setting?

BenTheGoodAg said:

---

Is this a new/increasing problem or just something that happens every winter? What is the temperature setting?

---

Happens every winter. Temperature is 125-130

Dang... Well in that case, it doesn't sound like there's anything wrong with the unit. It just doesn't meet your requirements...

But even if we use 40 gallons of hot water with a 40 gal water heater, I would have thought the recovery rate should keep up for a little bit and allow for 50 or so gallons.

I still don't understand exactly what this does or how it works. Any experience?

Quote:

---

It allows you to follow BenThe Good Ag's suggestion while avoiding the OP's scalding issue....

BenTheGoodAg said:
You could always increase the temperature setting and mix more cold water at the fixture. That would give you more capacity for showers. I don't know that I'd just max it so you don't scald yourself at your fixtures, but maybe increase 10 degrees and give it a try?

You're probably close to the end of life for that unit if it was new in 2014. Could keep running it, but a leak detector might be a good investment.

ETA - As to why - in the winters your cold water is at a colder ambient temperature. It takes more hot water to achieve the same mixed temperature at the fixture. 15 minutes sounds like a long shower to me. 2.5gpm fixture at 15 minutes is about 40 gallons if it's a hot shower.

---

I've played around with this and found that any higher of a temperature and I'm scalding myself at the sinks. And yes it's definitely due to the colder cold water temp in winter. I used to try to tell her to take shorter/not so hot showers then decided this was not the solution I wanted to pursue haha.

JP76 said:

---

Where is the water heater at ? Attic ? Garage ? Interior closet ?


Put this on it


https://www.homedepot.com/p/Cash-Acme-Water-Heater-Tank-Booster-24409/203721329


If it still is not enough hot water then go buy a 50 gallon rheem and put the above tank booster on it

---

Thanks for this suggestion! So excited to try it!

To reply to the person above saying they're not sure how this device works, the idea is to use less hot water out of the water heater, because you're mixing with 140F water instead of 120F. But then the device is basically a mixing valve that delivers 120F to the house, so you're not burning yourself at the sinks.

It's basically a big anti scald valve that works on the water heater. You can bump the heater up to 160 degrees if needed but the valve lets cold mix to get it back down to 120.
I have not personally had one but I know multiple people who have installed them and were happy with the increased supply of hot water.

That's a great device. I've seen one at the fixtures, but not at the supply. Thanks for sharing.

Good Bull Jones 17 said:

---

I have an AO Smith 40 gal electric water heater. Model # ECT 40 200. My wife runs out of hot water in the shower after about 15 minutes in the winter. I have replaced upper and lower elements and thermostats, the anode rod, and flushed out the WH. Still no improvement. We don't have any kids yet, and live in a 3 bed 2 bath house built in 2014.

Anyone have any ideas why I continue to have this issue?

---

There's part of the problem.

I just did the same thing. Got it installed last week. Wife is very happy.

You're not mixing cold water to the extent that you think you are. The Cold water enters at the bottom, and the hot water leaves off the top. With the two thermostats the unit gives preference to the upper one to maintain temp as the water leaves.

Thermally water does not like to mix and remains extremely well stratified.

How many shower heads do you have? Is your wife running a single rain head or 7 full body surround heads?

More than you ever wanted to know about your water heater.

Good Bull Jones 17 said:

---

JP76 said:

---

Where is the water heater at ? Attic ? Garage ? Interior closet ?


Put this on it


https://www.homedepot.com/p/Cash-Acme-Water-Heater-Tank-Booster-24409/203721329


If it still is not enough hot water then go buy a 50 gallon rheem and put the above tank booster on it

---

Thanks for this suggestion! So excited to try it!

To reply to the person above saying they're not sure how this device works, the idea is to use less hot water out of the water heater, because you're mixing with 140F water instead of 120F. But then the device is basically a mixing valve that delivers 120F to the house, so you're not burning yourself at the sinks.

---

Used in commercial applications quite a bit. Heat water to 140 to prevent legionella then temper back down.

It's just a regular single shower head.

Our water is extremely hard, and the first owner did not have a water softener (2014-2020). I put one in as soon as we moved in. I've flushed out the water heater multiple times, but maybe there's scale built up in in reducing the capacity.

JP76 said:

---

Where is the water heater at ? Attic ? Garage ? Interior closet ?


Put this on it


https://www.homedepot.com/p/Cash-Acme-Water-Heater-Tank-Booster-24409/203721329


If it still is not enough hot water then go buy a 50 gallon rheem and put the above tank booster on it

---

Interesting, do you use one?

I know you already said you are getting another heater.

One possible cause could be the inlet tube which takes the cold incoming water down to the bottom of the tank has broken off and is allowing the cold water to mix with the hot water. I've seen this in older heaters a couple of times.

Also, if you did not take heater out and vacuum or rinse out the lime (solids), there is till A LOT left in there.
You cannot get most of that out as the area cleared is the shortest path between the inlet and the drain valve.
You still have a pile of solids in the tank that will not move without further intervention. I always removed my heater and opened every port I could to be able to get solids out. Even removed the drain valve and replaced with a brass ball valve to increase flow. The factory plastic ones will not let larger lime chips out and the chips will usually keep that valve from sealing correctly.

I live with Edwards acquifer water and my experience has been a 40 gallon heater is at least 1/3 full of lime in 5 years.

Good luck with replacement.

Good Bull Jones 17 said:

---

JP76 said:

---

Where is the water heater at ? Attic ? Garage ? Interior closet ?


Put this on it


https://www.homedepot.com/p/Cash-Acme-Water-Heater-Tank-Booster-24409/203721329


If it still is not enough hot water then go buy a 50 gallon rheem and put the above tank booster on it

---

Thanks for this suggestion! So excited to try it!

To reply to the person above saying they're not sure how this device works, the idea is to use less hot water out of the water heater, because you're mixing with 140F water instead of 120F. But then the device is basically a mixing valve that delivers 120F to the house, so you're not burning yourself at the sinks.

---

Did you ever try the tank booster?

If you have the room, forget the 50 and replace your 40 with an 80........we did and have beau coup hot water.

What is she doing in the shower for 15 minutes ?

BCOBQ98 said:

---

Have some kids and she won't have time for a 15 minute shower.

---

or just let her take a shower which is only 12 minutes, then give her the best 3 minutes of your life in the bedroom afterwords.

texsn95 said:

---

JP76 said:

---

Where is the water heater at ? Attic ? Garage ? Interior closet ?


Put this on it


https://www.homedepot.com/p/Cash-Acme-Water-Heater-Tank-Booster-24409/203721329


If it still is not enough hot water then go buy a 50 gallon rheem and put the above tank booster on it

---

Interesting, do you use one?

---

Just installed it, on a 50gal gas heater, no leaks so far. We'll see if my twins ***** about each other using up all the hot water this coming week.

50gal/40 gal= 1.25
1.25 x 15 mins = 18 mins 45 seconds.
18 mins 45 seconds- 15 minutes = 3 mins 45 seconds

All for this for an extra 3 minutes and 45 seconds.