Water Heaters - New water heater problem

Hey all,

About a month ago I bought a new 50 gal electric water heater to replace an old one of the same size. From day 1 I've only gotten about 10 minutes of hot water in the shower compared to a good 20-25 minutes from the old water heater. So I called the company and the guy gave me a line about how, due to some new regulation, a new 50 gal water heater will only hold 35 gal of hot water so it was working perfectly well.

When the same thing happened with my old water heater, I replaced the bottom element and everything was fine, but I wouldn't think a brand new heater would have a bad element. Is this guy feeding me a line of bull or is 10 min of hot water the best I can hope for?

He's right about the 35 gallons. The incoming cold water mixes with the warm already in the tank, therefore you will get about 65 to 70 percent of the water heater's capacity.

It's possible your old heater was set to a higher temperature allowing you to use more cold water (and less hot water) at the shower.

The guy is a moron. A 50 gallon tank still hold 50 gallons. What has possibly changed is that for liability reasons, a new tank will come with the thermostat set fairly low.

Here is the 70% rule: Any water heater will deliver 70% of its gallon capacity at a temperature 20 degrees below the T-stat setting. SO for example, a 50 gallon tank set at 130 degrees will deliver 35 gallons at or above 110 degrees. Your new tank may be set at 120, so by the time you have used 35 gallons, the temp will jsut be 100 degrees.

You can increase your temperature, understanding the risks; especially if you do not have ant-scald type shower valve. The danger is especially significant for children and the elderly.

Ok, so I timed my shower the other day and I'm getting between 10 and 11 minutes before it goes completely cold.

The guy at the local plumbing store thought this sounded weird, too, so he had me check the elements and thermostats with a multimeter. The circuit seemed fine on both elements and both thermostats. But when I checked the voltage on the lower thermostat I couldn't get a reading. It seemed like there was power going to the bottom element, but not the thermostat. Is that even possible?

Keep in mind that most water heaters only power one element at a time. So, if you measure 240 volts at the upper, you will measure 0 at the lower. When the stat shuts off the upper, you should have 240 volts at the lower.

It's also possible that the dip tube has come loose. Instead of dumping cold water at the bottom of the tank, it's dumping it in the top of the tank, which is where the water is also drawn from.

Either you take really hot showers, have really cold incoming water, or the thermostat is set really low. I can take more than 45 minutes on my 50ga before I even have to touch the faucet.

My bet is on the dip tube.

I just installed a new 55 Gallon Kenmore heater on Sunday. I took a shower last night and the water got colder after about 10 minutes. The new heater must have a lower starting temp, than my old A.O smith heater. I turned it up to a hotter(B) setting(it has hot, then A, B, C, and hottest). This solved my problem.

Well, I thought it solved my problem. Turns out the water is just hot for a little bit then starts to get cold. I'm having Sears come out and inspect it.

Yeah, I got the same thing. I turned up the t-stat, but now I just get hotter water for 10 minutes. I tried to get to the dip tube, but it looks like it is beneath the heat trap and it's too far down to reach with a finger.

I had the Sears guy come out for my water softner that wasn't working and he inspected the water heater. Apparently there are two thermostats on the water heater and I'm an idiot for not noticing that. I turned up the bottom thermostat and magically I have hot water all the time..

>> Apparently there are two thermostats <<

That's why you should read the instruction manual :)