Water Heater Repair Help

[jrossano]

I just moved into a house with two 2003 GE GE50M6A water heaters. I tested them with a multimeter and the first one (with the cold water intake) had a bad thermostat. So, just to be safe (and because they are beyond their service life), I changed the upper and lower thermostats and both elements on both of the water heaters.

I checked the voltage and continuity of everything again, and everything checked out ok - power, thermostat, limit switch, elements. I set all the thermostats to 125 last night. We have hot water at the faucets, however, when I open the bottom drain valve of the first water heater the water that comes out is ice cold. The water coming out of the second water heater bottom drain valve is nice and hot. Any ideas what might be wrong?

 

[Vance R]

Are these water heater plumbed in series or separate?  Generally the way water heaters work is cold goes to the bottom of the tank and hot water goes out the top of the tank. The heating elements are usually setup to have the upper element common and heat top portion of the tank, when water get hot enough the upper thermostat turns off upper element and sends power to lower element/ thermostat. When the water in the bottom of the tank gets hot enough the lower thermostat cut power to the lower element. 

From your description of the first tank water temp the lower element should have power.  Check for 220 vac at lower element and/or amp draw.

[tech7]

When calling for water the incoming water should be directed to the bottom of the tank through what is called the dip tube. If the dip tube is defective, which has been very common. The dip tubes fall apart and have to be replaced. You can do a draw test on the water heater from the bath tub into a 5 gallon bucket and see how much hot water their is. If you pull the aerator off you faucet  you will find white or blue plastic material that if you rub between your fingers it will dissolve . A tell tell sign the dip tube is defective.