Melting element wire on new WH

[Devino]

My father recently installed a Westinghouse 80 Gallon 5500w water heater. The following day when he was turning up the temperature on the thermostats he noticed plastic on the lower element and nylon on the attached wire was melted. This melting continued to get worse that morning until he turned off the power. I replaced that wire with a slightly larger #10 wire (imaged below) and the overheating has stopped. Everything seems to be working correctly now. Notice the discoloration on the thermostat temperature set screw and label. The wire got hot.

Here is the old wire and thermostat cover.

Has anyone seen a problem like this or know what could be the cause?
I have sent Westinghouse an email with these images and a description.

 

[Bannerman]

Are you able to measure the incoming voltage to compare against the WH rating plate?

 

[Sponsor]

 

[Phog]

You can get melting like this if the wires are not secured properly to the terminal screws. Not tightened well or else bad contact from foreign material getting in the way. For example if the screw is tightened down onto an insulated part of the wire instead of bare stripped copper. When this happens the junction heats up and conducts heat a few inches down the wire, scorching the wire insulation over that length.

 

[Fitter30]

The pic of the bottom element needs to be replaced because the terminals have been over heated that is why there is that dark discoloration. Wire has to nice and shiny for a good connection. All terminals should be checked for tightness after heater is up to temp.

 

[Devino]

Thanks for the replies.

Are you able to measure the incoming voltage to compare against the WH rating plate?

I have only measured current flow (240v light tester) on both elements. I can measure the voltage tomorrow. Are you suggesting a possible reduced voltage might cause the wires to overheat?

You can get melting like this if the wires are not secured properly....

Maybe the connection on the left side of the element had some resistance that caused the overheating yet I cannot confirm this due to the damage. The screw seemed tight enough when I removed it yet it could have been loose or otherwise had poor contact to have been the cause of the problem.

The pic of the bottom element needs to be replaced...

I received a reply from Westinghouse this morning requesting information for processing a warranty claim to replace this unit. It is quite scary considering what could have happened if this was left unchecked. In my opinion it appears to be resistance on that element screw that caused overheating. I think I will put a small smoke detector in that closet just to be safe.

 

[Phog]

Maybe the connection on the left side of the element had some resistance that caused the overheating yet I cannot confirm this due to the damage. The screw seemed tight enough when I removed it yet it could have been loose or otherwise had poor contact to have been the cause of the problem.

It's also possible that there was poor electrical contact internally somewhere within that heater element, that then caused heat to be conducted out through the terminal into the wire. In my opinion that's less likely than a simple case of bad terminal contact but it's hard to say for sure. Anyway I agree that it's scary and hopefully Westinghouse goes above and beyond to get this fixed for you.

 

[Jadnashua]

You really want the wire to be at least 180-degrees wrapped around the screw - a bit more doesn't hurt, but makes it more of a pain when you ever try to remove it at some later time. It needs to be shaped well, too, so that it is pushing done on the wire and not trying to push it out because it's rounded. If you have some solder eyelet or spade terminals, that's even better, but not required. WIth either of those, you're trying to clamp a flat surface underneath the screw.

 

[Devino]

I wanted to follow up that Westinghouse has sent a new water heater. It arrived on Wednesday and was installed that day. Everything is functioning properly and my father is very pleased. He was convinced that the warranty was void since he installed it himself and was delighted at the fast response I received after my initial email to the company and particularity that they honored the warranty.

We would also like to thank everyone here for their advice. The Terry Love plumbing website, and this forum, has been a valuable asset for us over the years. Thank you everybody, keep up the good work.

 

[Fitter30]

It's nice to hear when a company does the right thing.

 

[Onokai]

#10 wire is the right size to use and wrap it more around the screw so the contact area is larger. Looks like the wire was a#12 and was barely contacting the screw.