Warm water condition in house

[Jomo1]

My friend put in an electric hot water heater for me five years and all has been fine until this past week. I did take my friend's advice and I drained out the water from the tank once a year.

Recently we are not getting very hot water in our house.

Here is what I have done so far.
1) I confirmed that the upper heating element is getting voltage ( I forget if it is 120v or 240 v)
2) Same voltage for the lower heating element.
Note: Only one heating element had voltage at a time
3) I checked the ohms reading across the heating element with wires disconnected and got a reading of 13 for both the upper and lower heating element.

That is all I did. Any ideas as to what else I should check?

Thank you,
Jomo

 

[Reach4]

You should have turned off the power before draining the tank. You should have filled the tank with water, opening a hot water faucet to let air out. Only after the tank was full of water, and water was coming freely out of that open faucet, should you have turned the power back on.

One of your elements is probably bad. You can measure the current to the WH. If the element is good, and there is voltage across the heating element, then there should be a lot of current flowing.

 

[Sponsor]

 

[Jomo1]

Thanks for your reply.
I actually did do everything that you said in that order. Any other ideas?

 

[Bannerman]

The lower thermostat is powered through the upper T'stat. The lower T'stat is likely single pole as shown in the link below. If the lower T'stat is not allowing power to flow to the lower element, the voltage you measured at the lower element would be supplied by the non-switched conductor with voltage flowing through the element to the non-powered side of the element so voltage will be measured.

https://images.app.goo.gl/7iKeJCs926seCEDCA

 

[Jomo1]

Bannerman, thanks for your reply.
So you are saying that it is possible that the lower heating element can have voltage measured across it but the element still is not powered. That makes no sense to me but that does not matter. How can I tell if the lower element is in fact getting power?

 

[Bannerman]

possible that the lower heating element can have voltage measured across it but the element still is not powered

You were not specific on how you measured voltage. A large WH with 2 heating elements will operate using 240 volts but you mentioned 120 volts which would be correct if measuring the voltage from each 'hot' conductor to ground.

If you did measure across both of the 240 volt lower heating element terminals, there would be no voltage reading if one of the conductors was not powered, but if you measured each terminal in reference to ground, then voltage would be seen on both terminals.

Reach4 suggested measuring current flow. The video below shows how that. Although the video discusses 120 volts, the procedure is identical for measuring the current through your 240 volt heating elements.

 

[Phog]

You can buy a kit with all parts for a complete rebuild (elements, o-rings, and thermostats) for cheap, like $35 at the big box home center. Installing everything in the kit takes maybe an hour. Rather than trying to guess and spending time troubleshooting, sometimes that's the best option.

 

[Jomo1]

You were not specific on how you measured voltage. A large WH with 2 heating elements will operate using 240 volts but you mentioned 120 volts which would be correct if measuring the voltage from each 'hot' conductor to ground.

If you did measure across both of the 240 volt lower heating element terminals, there would be no voltage reading if one of the conductors was not powered, but if you measured each terminal in reference to ground, then voltage would be seen on both terminals.

Reach4 suggested measuring current flow. The video below shows how that. Although the video discusses 120 volts, the procedure is identical for measuring the current through your 240 volt heating elements.

I measured the voltage with my leads touching both wires and got voltage, so it must have been 240v

 

[Jomo1]

You can buy a kit with all parts for a complete rebuild (elements, o-rings, and thermostats) for cheap, like $35 at the big box home center. Installing everything in the kit takes maybe an hour. Rather than trying to guess and spending time troubleshooting, sometimes that's the best option.

I will look into that and keep you updated. Thanks!

 

[Sarg]

With your heater being 5 years in service .... study up on replacing the anode rod. If you want your tank to last the anode rod must be replaced if it has deteriorated............ otherwise your tank will rust out in a short time.

 

[Phog]

I will look into that and keep you updated. Thanks!

The other golden rule (as Reach4 mentioned), keep electric power OFF to the tank if there's any air inside it. Only flip the breaker back on after all the trapped air is gone. Good luck.