Hot Water Shortage: Possible Causes
LESLIE: Taking a call from Alice in Florida who listens in to The Money Pit on WCOA. What can we help you with?
ALICE: Hi. I’ve got a – two water heaters in our home. They’re both 40 gallons. And one of them, which is on the master bath side of the house, does not fill up our master bath tub. And it has Jacuzzi jets but it fills the water up to, say, the level right below the jets and then it runs out of hot water.
TOM: Hmm. Is it a gas water heater or electric, Alice?
ALICE: It’s electric.
TOM: Alright. And is it a 40 or 50-gallon electric water heater?
ALICE: Yes, 40.
TOM: Did it ever fill up the whole tub or is this a new problem?
ALICE: No, well we just bought the house, so …
ALICE: … ever since we’ve moved in …
ALICE: And we turned up the – we turned it up to 140 degrees.
TOM: That’s way too hot.
TOM: Here’s what I want you to check. Is this one of the tall water heaters?
ALICE: No, it’s a short.
TOM: Short, squatty one?
TOM: Does it have – do you know if it has one coil or two coils?
ALICE: It has two, which we checked.
TOM: So do you know that both coils are working?
ALICE: Yeah, they both work.
TOM: How do you know that?
ALICE: Our neighbor had a little instrument and he tested it.
TOM: He did a continuity test? That’s what has to be done. Because what you’re describing is a typical failure of one coil or the other. You’re only getting half of the hot water that the unit is designed to put out. And so you need to make sure that both coils are truly functioning. That doesn’t just mean they’re getting power. It means that the coils have not broken down. And the way to test that is with a continuity tester and, frankly …
LESLIE: Do you hire a plumber to do that or is it something you can do on your own?
TOM: (overlapping voices) Well, I was going to say it’s not really a do-it-yourself project because you have to be comfortable working amongst 240-volt electricity to do this. If your neighbor knows how to do that you can confidently turn off the circuit to the water heater and disconnect one of the leads and test it; then that’s fine. But if you don’t have that level of expertise then don’t do it because it’s dangerous.
But that’s what this sounds like to me. It sounds like one of the coils is not working and therefore you’re only getting half of the hot water. And once you get it fixed you’re going to be in good shape. Because I seriously doubt that they put in a water heater that was undersized from the get-go because there would have been a lot of complaints by now. So it sounds like one coil is burned out. And that’s actually an easy thing to fix.
ALICE: So it’s called a continuity tester?
TOM: Yes. You have to check the coil with a continuity tester. It basically tells you if the coil is working. There’s two heating coils in a water heater; usually one higher, one lower. And if one gives out then it’s just not doing the job. OK?
TOM: Alice, thanks so much for calling us at 888-MONEY-PIT.