Water Heaters - Hot Water Running Out

We recently purchased a condo unit with a 50 gallon water heater and a showerhead limited to 2.5 gpm. As a side note – if it matters, our inspector during walk through found our water heater was short-circuiting. The builder fixed the problem.

However, when taking two consecutive showers (not lasting 5 minutes each – 10 minutes total) the hot water runs out at the end of the second shower – starting to turn lukewarm. We have turned up the thermostat on the water heater and are not running the washer or dishwasher at the same time, or even beforehand, but this has not helped.

The builder told us that a 50-gallon water heater tank will only provide 32 gallons of hot water, and that once we deplete 32 gallons the water will start to recycle and become lukewarm. Is this true?

Welcome to the forums. It seems as if one of your elements, probably the bottom one is burned out. All you are getting is the water heated by the top element, and when the cold water rises, it is not heated by the bottom element first, so you get lukewarm water. Turn the thermostats back down! Once you fix the element, you will have too hot water and can scald someone. If you need help diagnosing the element, please post back and we can guide you through it.

You didn't say if this is a new WH or old...if its the right age, it could be a dip tube issue as well.

This is info about water heaters, tho a gas unit is shown. the plumbing is the same


http://homerepair.about.com/od/plumbingrepair/ss/hwh_tank_gas.htm

Thank you for the replies. It's a new water heater. Also, the builder had a plumber come in a change the lower thermostat - is that the same as a heating element?

Is it not typical for a 50 gallon water heater to only have 32 gallons of hot water – as the builder claims, or should it have 50 gallons? I’m new to home ownership and water heaters, so I don’t know if I’m being fed a line b/c they don’t want to give me another water heater.

Typical is about 80% of capacity before you start feeling a change in water temp.

If this is new construction, its all on the builder. If you have a 2.5 gal flow showerhead then 2.5 x 10min=25gal use. So even by your builders calc's you should not run out. Thats also considering running purely hot water, you aren't unless yer a lobster with a death wish...lol. But thats not taking into consideration that the water heater will be trying to heat water as it comes in.

I've never had bigger than a 40 gal (granted, they were gas) but it would take 3-4 people taking long showers to really run out.

You can also look at the WH manufacturers site, and normally be able to find charts with the available hot water and the recovery time for the WH. (recovery time is how long it takes to rewarm the tank to operational temp).

I'd invite the builder over for a nice long hot shower, then see how he feels. Something is not right.