Jump to content

Overly-hot water heater


Bain
 Share

Recommended Posts

I woke up to mostly cold water this morning. I checked the 4-year-old heater and the hi-limit reset button had popped. I reset it, and moved the temperature-control dials to "A", but when I came home for lunch later, the water temperature was nearly 150 degrees. I disconnected power, figuring one or both of the thermostats was shot.

When I got home from work, I checked the thermostats for voltage, and didn't find any at the terminals. Since I second-guess myself about stuff like this, I downloaded the manual--see page 32--and realized I'd remembered correctly how to determine if the thermostats were faulty.

I suppose I'll replace both thermostats and hope that solves the problem, but I was wondering if there was anything else I should investigate before I spend the $$ on thermostats.

http://www.bradfordwhite.com/images/sha ... 04-00A.pdf

Link to comment
Share on other sites

You might check the appliance for shorts to ground. I do this by first clamping my amp meter on the grounding conductor leading to the appliance, then double chk it by checking for voltage between some other grounded connection (other than the grounded conductor) and the tank. The thermostats are single pole switches, meaning that when a thermo is in the open position (temperature has been satisfied) there is still voltage on the element, so if there's a short to ground on the element or element wiring that isn't a dead short, current can still flow and heat the water (or something).

Marc

Link to comment
Share on other sites

You might check the appliance for shorts to ground. I do this by first clamping my amp meter on the grounding conductor leading to the appliance, then double chk it by checking for voltage between some other grounded connection (other than the grounded conductor) and the tank. The thermostats are single pole switches, meaning that when a thermo is in the open position (temperature has been satisfied) there is still voltage on the element, so if there's a short to ground on the element or element wiring that isn't a dead short, current can still flow and heat the water (or something).

Marc

Thank you. I followed your advice and didn't see anything out of whack.

I won't have time for a trip to the plumbing supply jolnt till Monday. My new note beside the coffee pot will read, "Turn on the water heater so you can take a WARM shower."

Link to comment
Share on other sites

John, do you have a link for an online manual - more to the point a wiring diagram?

No, I just Googled Bradford-White manual, and found the service guide. The heater's been problem-free since I installed it a few years ago. I read something somewhere during my Google search that high-lime areas can screw up the lower element and cause it to overheat, but that doesn't really make sense. If replacing the thermostats doesn't cure the problem, though, I'll probably switch out the element.

Link to comment
Share on other sites

Pull the elements and look at them. If they are covered with heavy mineral deposits you might be able to clean them with CLR or white vinegar. They can overheat so to speak and trip the thermostat.

My bet is on the lower thermostat and that is has gone bad. I replaced one on my WH and I think it cost around $12 or so.

Link to comment
Share on other sites

Pull the elements and look at them. If they are covered with heavy mineral deposits you might be able to clean them with CLR or white vinegar. They can overheat so to speak and trip the thermostat.

My bet is on the lower thermostat and that is has gone bad. I replaced one on my WH and I think it cost around $12 or so.

I called a plumber friend, this morning, and he also said the lower thermostat is the one that usually fails. But, he also said he always replaces both the upper and the lower to avoid callbacks.

Link to comment
Share on other sites

I made it to the plumbing supply joint, after all. The counter guy said the upper thermostat hardly ever goes bad, and that I really only needed the lower one. Nine dollars, three minutes of time, and voila! Problem solved.

Click to Enlarge
tn_2010820193726_DSC05624.jpg

29.97 KB

Link to comment
Share on other sites

There's always the big orange box. I used to go there so much that they once asked if I'd like to set up a bedroom in the back of the store to move in.

Marc

That occured to me on a trip to Big Blue not long ago.

I thought if I'm going to be coming to the home center so often, might it not make better sense to just move into one of the aisles at the home center?

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

×
×
  • Create New...