Hot water not what it used to be

[Banjo Bud]

lately I’ve noticted I need my shower mix valve turned more to the hot side to get the same heat I used to. I have a 12 year old, 40 gal, electric tank. I also have a water softener system and an acid neutralizing tank. My PH is 7-7.2 consistently. I checked both elements and they are good. 13 ohms. I drain water from the tank every other month. I’ve never gotten any crap though. Just clean water. I replaced the anode rod about 4 months ago. The original was 80% gone. I did a test today. I got the shower adjusted to a good temp at about 1/2 full on volume. The I pulled the knob straight out, which in theory gives me more water without changing the mix ratio. The water went cold. I needed to turn the knob more toward the hot side to get the same temp I had at 1/2 volume. I’m wondering if it’s posdible that the output pipe from the hot water tank is built up with junk and not allowing enough water through it. If that’s the case, I guess it’s new tank time?

 

[Phog]

It could be that the dip tube is broken. The dip tube sends incoming cold water way down to the bottom of your tank. This way water near the top of the tank stays hotter, longer. If the dip tube gets cracked or falls off the incoming cold nipple, then the cold water can come in and go straight back out the hot line before it heats up. This isn't something that's typically repaired, it's a sign that you need a new tank. Sorry for the bad news.

 

[Sponsor]

 

[Banjo Bud]

That makes more sense than a corroded pipe because it happened suddenly. Either way, it’s new tank time. I was really hoping that with a softener and acid neutralizer that my hot water tanks would last longer.

 

[Phog]

Yeah unfortunately there's no magic way to preserve a water heater for 100% certain, you can do everything right and still only get average life. In fact it's even possible that frequently draining & flushing out the system actually contributed to a dip tube failure. Damned if you do, damned if you don't!

12yrs isn't bad though, i wouldn't say you got cheated. Even though i know you were hoping for more.

 

[Jadnashua]

If it's not leaking, a new dip tube might help. Generally, you'd replace the WH when it leaks, or if it's in a place where leaking could damage things, maybe on a schedule. A WH can last anywhere from a few years, to over 20, but 7-8 is more common. An electric one can last longer than a gas one, but that's not guaranteed, either. There's a reason most have about a 6-year warranty on them.

 

[Banjo Bud]

How does one replace a dip tube? And where do I get one? I’m a huge DIYer so I’m not afraid to try. If it costs less than $50, I’d say I’d do it.

 

[Reach4]

How does one replace a dip tube? And where do I get one? I’m a huge DIYer so I’m not afraid to try. If it costs less than $50, I’d say I’d do it.

Way less than $50. You could call the maker and get the tube, but they are common enough in your big box store or plumbing supply.

What WH? Search for "dip tube" with the quotes on the website of your favorite seller.

 

[Phog]

You could give it a shot if you're comfortable, the parts are cheap. The reason this isn't a super common repair is due to the labor involved. Often all the connections on the water heater have to come off, to allow it to drain and flip on its side, due to inadequate clearance above for changing the tube. It's more involved if you have a gas unit than an electric, due to the additional connections. By the time you pay a plumber to take everything apart and put it back together, you might as well put a new WH in. It's good that you have electric & if you're not scared of the job maybe you can get some more mileage. I'm not a pro, maybe someone else here could give you a pointer or two on choosing a "universal" dip tube vs manufacturer genuine.

 

[Banjo Bud]

I’ll check for an OEM tube when I get back home next week.

 

[Reach4]

Often all the connections on the water heater have to come off, to allow it to drain and flip on its side, due to inadequate clearance above for changing the tube.

I don't think that you would usually have to move the WH, especially if the WH were in a basement.

https://terrylove.com/forums/index.php?threads/where-to-buy-a-dip-tube.30473/ #4 has some comments including

I believe dip tubes are generic. This is why there were so many problems in the mid 1990s with many brands of heaters having dip tube failures. They were all, or nearly all, made by one manufacturer.​

 

[Phog]

I don't think that you would usually have to move the WH, especially if the WH were in a basement.

It's the same issue that people often run into when they're replacing the anode rod. Often there isn't enough clearance between the ceiling & the top of the water tank to install the new one. They make the segmented style anode rods for this purpose. I'm not aware of an equivalent product for dip tubes.

 

[Banjo Bud]

I thought the dip tubes were plastic?

 

[Phog]

I thought the dip tubes were plastic?

They are, you still need a couple feet of head room above the heater to work with, or else the tank needs to be drained and tipped at an angle (or moved to somewhere with adequate clearance). If you successfully replaced the anode rod in place with a solid non- segmented rod then you should be able to do the dip tube in place too. Perhaps some of the pros here can chip in with advice, I've never seen one replaced.

 

[Banjo Bud]

I did a solid anode so I should be good.

 

[Jadnashua]

The dip tube is fairly rigid and long, and you can't get a lot of angle on it trying to install one, so it needs to come up fairly straight.

Back a number of years ago, there was a rash of dip tubes that degenerated and fell into pieces. That caused rapid dilution of the existing hot water. While that problem doesn't seem to be around anymore, anything's possible. The part is cheap. If you're willing, you may see an improvement, but you'll probably know when you try to pull the old one out. IF it's intact, there won't be any improvement with a new one.

If the lower element is not working, you may not have a full tank of hot water. What normally happens is that the top one turns on first, then, once it is satisfied, the lower one comes on to finish up the job. That gives you some hot at both the beginning and end of the hot water supply, but without the lower one coming on, the whole tank won't evenly come up to temperature. That could be a thermostat issue, and the element could be fine.

 

[Banjo Bud]

I know there’s a way to check voltage drop on an element because I’ve done it before, but don’t remember how. I checked the resistance and it was good at 13 ohms. But maybe I need to check voltage. Can anyone tell me how?

 

[Phog]

I know there’s a way to check voltage drop on an element because I’ve done it before, but don’t remember how. I checked the resistance and it was good at 13 ohms. But maybe I need to check voltage. Can anyone tell me how?

Voltage drop is proportional to resistance, so you already made this measurement. You can also check the isolation resistance -- aka the resistance between the element & the chassis (any exposed, non-painted section of the water heater will do). Usually if there is a problem here your breaker will trip so I'd be surprised if you found a problem, but it's not impossible. Based on your initial description I still think it's most likely the dip tube, but jadnashua is right that you should rule out the thermostats in addition to the heater elements.

I also just wanted to point out that new 40gal electric water heaters are pretty cheap. I got one from Home Depot for $329 last year. Your time is worth something!

 

[Banjo Bud]

Yes. Time is money.

 

[Reach4]

Yes. Time is money.

I would be pretty slow installing a new WH and getting the old one up out of the basement. A dip tube sounds a whole lot faster to me. But I am slow.

 

[Jadnashua]

The best way to test the operation of an electrical load is a clamp-on ammeter. Voltage readings can be misleading.