Hi all – I’m having a problem with a hot water heater in a rental house I own. I did a complete gut / rehab last year and had all the plumbing replaced, so this is less than a year old. It’s a 50 gallon electric unit in a small dug-out basement. These tenants have been there about 6 months and not the type to complain much, so I know they are not jerking me around.
A couple of weeks ago, they said that their 2nd shower in the morning was not warm enough and asked if I could do something – I cranked the temp up a little, and they reported that it was much improved.
Just now they sent this email: “We ran out of hot water last night and this morning, which has not happened before — last night for a bath, and this morning the first
shower was hot then luke warm and the second one was luke warm/cold, even after he waited about 30 minutes after mine. I’ve been getting hot water in the kitchen today, I think it’s just running out faster than usual, my guess from last nite and this morning is it starts to cool down after about 5-10 minutes.”
So my question: where do I start? I’ve never worked on these, but am willing to dive in. My uneducated guess is that one of the heating elements is burned out (they have 2, right?). How would I diagnose that, how hard are they to replace, should it be warranted by the manufacturer and/or the plumber who sold it to me? What else could it be?
Thanks!
Replies
If the electric water heater is actually making hot water, but it doesn't supply much of it, sounds like it could be either the lower heating element or the the dip tube. If you want to dive in, disconnect the water heater and remove the fitting at the top of the water heater where the cold water goes in. There should be a long tube connected to that fitting. If it's not there, it fell into the water heater (in which case it would be a warranty issue in my book -- I have no idea how you'd get it out of there and I wouldn't want it floating around in an electric water heater if it were me).
If the dip tube is there, I'd check the lower element. There should be some sort of access panel. Remove the wires connected to the element (you already disconnected the water heater, so it's not powered, right), and measure the resistance across the element. The resistance should be low. If it's very high or infinite, replace the lower heating element.
If all this sounds like giberish, you probably should call a plumber.
"A job well done is its own reward. Now would you prefer to make the final payment by cash, check or Master Card?"
Thanks for the quick reply - no, not gibberish at all. I don't know why I didn't think of checking the resistance ... Is it common for an element to burn out in 1 year?
>>Is it common for an element to burn out in 1 year?
Nope. It's also no longer common to have a problem with the dip tube. Stuff happens though.
Also, if you have really hard water, the element could be encrusted -- which actually reminds me of a final last-ditch thing you could check -- the lower heating element might be encrusted. If there's enough crap encrusted on it, its thermostat might make it think the water toward the bottom of the heater is hot when it's actually not (maybe heat transfer through the lime deposits from element to its thermostat is a heat transfer "short circuit").
"A job well done is its own reward. Now would you prefer to make the final payment by cash, check or Master Card?"
You have, by my estimation, five variables: Thermostats (2 each), heating elements (2 each), dip tube, installation, and operator malfunction.
The dip tube and installation possibilities are related -- bass akwards installation can look like a bad dip tube, and bad installation can cause the dip tube to fail. Either of these will cause water to go from hot to lukewarm real quickly, but one will be able to draw warm water for a long time.
Sorting out between heating elements and thermostats can also be a trick. On my unit I actually installed neon indicators on each element so I can tell when one's getting power -- makes diagnosis a tad easier.
But if you have a situation where the water gets real, real hot, and then 12 hours later is cold, that's almost always a bad thermostat.
Beyond that you have to get out a meter and check the voltage on each heating element. In normal operation when hot there should be no voltage on either element (measured between the terminals -- they will be "hot" if measured to ground/neutral). When cold there should be voltage on the hot element and not the bottom one.
If there's voltage on the top element and the unit remains cold then the top element is almost certainly burned out. If no voltage on the top element when the unit is cold (and there IS power from the breaker) then either the top thermostat is gone or its overtemp breaker has popped. Reset the overtemp breaker and see if you get juice. If the overtemp breaker keeps throwing (after the water gets real hot as mentioned earlier) then one of the thermostats is sticking -- just replace both vs messing with it.
If the heater warm so there's no voltage on the top element, check the bottom one. (The top thermostat turns off power to the bottom element when the top one is activated.) If the bottom element is getting juice and it doesn't seem to be heating the entire tank then likely the bottom element is burned out. (A clamp-on ammeter is real handy here.) If the top is warm (no voltage on the top element), the bottom cold, and no voltage to the bottom element then likely the bottom thermostat is gone.
And of course operator malfunction basically involves leaving the water running too long.
happy?
Thanks for the thorough response. This job turned out to be simple - I went over this AM, killed the power and removed the covers. The problem was instantly obvious - the end of the lower heating element was severely burned!
My theory: all of the wiring looked shoddy to me - the wires were 'stabbed' in under the screws on both the heating elements and thermostats - none were wrapped around the screws. I'm guessing that one worked itself loose and arced, creating a little fire. The phenolic insulator at the end of the heating element was toast. By the way, this explains the call I got from the tenant last week reporting that the smoke detectors had gone off in the middle of the night, then quit. I went over there and found nothing at that time - no smell or anything - thought maybe a spider had crawled into one or something.
I bugged everything out, and it was all fine electrically, but the one wire from the lower thermostat to heating element had vaporized. After draining the tank, I replaced the element (took about 2 minutes, once I realized there was a 'special' wrench), then fixed all of the wiring (took maybe 10 minutes).
I'm curious - are these shipped from the factory pre-wired or should I give my plumber a hard time the next time I run into him at the bar?
Thanks again!
Yeah, come to think of it I had that happen on our heater, though the element wasn't so badly charred that it needed to be replaced. Had to replace a length of wire, though.Was so long ago, I don't recall if it was a factory connection or one that the plumber had monkeyed with the first time we had an element replaced. (After that I started doing all my own service.)The units are shipped factory-wired, for the most part. They'd only be touched in the field if some special arrangement was wanted such as a timer on only the lower element.Re the element wrench, when I had to replace an element about 10 years ago I ended up renting an impact wrench as the element just wouldn't budge otherwise. The impact wrench only cost about $5 for two hours (and I only used it 30 seconds), but had to drop about $20 for the socket, IIRC.
If ignorance is bliss why aren't more people
happy?