Help troubleshooting hot water running out quickly (replaced dip tube already).

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Tireshark

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This is a rental and the tenants recently began reporting that the hot water was running out quickly when taking showers.

I inspected the dip tube and it had holes in it, and was extremely brittle... couldn't pull it out because it broke, so i just pushed it off to the side and installed a new dip tube (no threads on the new dip tube, it just slid down in the hole).

They are still reporting short showers, but they also say that it seems like they can use the hot water in the kitchen for forever... it's just that the hot water runs out fast in the bathroom.

I dont know how much attention they are paying to everything, so i'm going to go over there today while they are away for thanksgiving and try to do some troubleshooting.

The shower is controlled by two handles... it isn't a one handle type of deal.

Water heater is a 30 gallon gas heater, manufactured in 1992.

1. There dont appear to be any leaks, but i haven't inspected underneath the house yet. Still, if they have plenty of hot water in kitchen, that tells me that there probably arent any leaks. Is there anything screwy that could be going on with the pipes/assembly of the shower that could cause this issue?

2. The burner fires properly when you turn on the hot water. Could the thermostat be malfunctioning and causing it to turn off too quickly (I have it set to the highest setting at the moment)?

3. I plan to go over there and test it with a 5 gallon bucket at the tub. I want to make sure the tank is fully heated before i drain it... am i correct in assuming that the burner will stay lit until the tank is fully heated? If so, then i will wait for the burner to turn off, and then i will run only the hot water and see how much i get. Is this the appropriate way to do a test like this?

This really sounded like a dip tube issue, and when i saw that the old one had holes in it, i thought for sure that replacing it would fix this problem. I'm trying to think if i could have messed up that installation, but it just sits down in the hole... so i dont think i could have. I suppose a little water might seep around the lip of the tube and enter the top of the tank, if it wasn't a tight seal, but i wouldn't think that that would cause a big problem.

Any ideas are very much appreciated. I may have some more info once i go over there and test it out more thoroughly. I'm most interested to know if my method for testing the hot water output is correct (i.e. wait for the burner to turn off, and then start running the hot water).
 

Terry

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A twenty three year old water heater that's only 30 gallons?
It may be filling up with sludge and reduced to nowhere near that amount.
The smallest water heater I've seen installed for homes is 40 gallons.
I would at the least, pick up some shower heads that are 2 gallons or less a minute. They may have heads that are just dumping water.
 

Tireshark

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Thanks terry, i haven't done my test with a bucket yet, but they said that when they first moved in they had a lot more hot water than since this issue started happening. So it sounds like it might not be a sludge issue, unless it got really bad recently or shifted or something.

Here is a bit more info:

This is the handle setup for the tub/shower:

http://i.imgur.com/0izs5rr.jpg

Gerber handles with these stems:

http://i.imgur.com/2uBSQ5t.jpg

Now that i think about it, i recently replaced the packing and washer on the cold water stem because water was leaking from the handle. I also removed the hot water stem just to inspect, and re-installed it back. I also believe that the issue with cold showers started shortly after i did this repair. Is it possible that something with my repair affected the hot water at the shower?

One last note... when re-installing the nut that holds the packing in place on the cold water stem, that nut shattered (i guess because i was clamped down to hard with my vise grips). It was extremely tight when it shattered, though, so i just left it that way and reinstalled it. There were no leaks visible either at the handle or underneath the house, so i assumed that it was okay. I doubt this has anything to do with the hot water issue, but just providing the info.

This is the nut that shattered:

http://i.imgur.com/s0KJ7CS.png

Also, the only connections in the house are 1 kitchen sink, washer hookups, 1 bathroom sink, toilet, and tub/shower.
 

Tireshark

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Hmmm okay. I guess since they said they had plenty of hot water before, i thought the appearance of this problem might be unrelated to how much water they are using (as long as they haven't changed their habits drastically from a few weeks ago, of course). I'm about to go test it with a bucket.
 

Tireshark

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Went to the tub and only got about 16 gallons of hot water out, so definitely an issue somewhere. Might be the tank i guess, but i would hate to replace it and still have this issue if it is something else besides the tank. Will check the hot water output at kitchen sink next, just to see. Also will check meter to make sure there isnt a leak anywhere.

Could the thermostat be malfunctioning? Maybe not heating the entire tank up like it should? What puzzles me is that this problem seemed to just appear a week ago... but i guess parts have to fail at some point... but it seems a drastic difference in such a short time.
 

Gary Swart

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You have a 23 year old tank that has already lived at least twice as long as long as normal. It is almost certainly half or more filled with crud. How much longer do you think it should last? Maybe if it was in your own home you'd be willing to try to squeeze some more life out of this beast, but how can you expect renters to live with it? I'm sure you expect the rent to be paid on time, no excuses. Replace this tomorrow.
 

Jadnashua

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A possibility, but not a certainty, is if there's a defective valve somewhere (some single-handle valves can do this), the hot and cold are crossing over internally, diluting the hot output. The water will take the path of least resistance, and the kitchen or other points may not be affected (could be the problem in itself). Try turning off the hot supply at each fixture and run your test. IF you get more volume, then start opening up the hot supply one-by-one to isolate it to the culprit. You only need to do that with single handle faucets. This is an internal leak, and may not actually leak out.

Check the gpm out of the showerhead while you're at it. Someone may have removed the restrictor (some have that, some just have a hard restriction built-in but sometimes, people drill them out). Federal mandates are that it should not flow more than 2.5gpm, and there are some decent designs that will provide a nice shower at less than that.
 

Tireshark

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You have a 23 year old tank that has already lived at least twice as long as long as normal. It is almost certainly half or more filled with crud. How much longer do you think it should last? Maybe if it was in your own home you'd be willing to try to squeeze some more life out of this beast, but how can you expect renters to live with it? I'm sure you expect the rent to be paid on time, no excuses. Replace this tomorrow.



It's not about how long i 'think' it can last, it's about whether or not the issue is with the hot water heater or something else in the house. Did you know that some people replace their water heaters, when all that is wrong is a $10 dip tube? Did you know that sometimes plumbing issues in places unrelated to the water heater can cause hot water issues? So if i put a new water heater in, and it isn't the water heater, how has that resolved the issue? Sure i could immediately go out and buy a $500 water heater each time a tenant tells me that their hot water is acting up, but silly me, sometimes i'll spend a day or so troubleshooting the problem if it isn't a critical issue.

For example when one set of renters moved in, they told me that their oven (which probably has a good 20 years on it) wasnt working. I said, 'well maybe it's time to go get a new one, but let me check a few things first'. Would you believe it was just a $15 igniter, and after i replaced it they said it works great? How about that, huh?

As far as me 'expecting' renters to live with it, that's quite an assumption for you to make. My renters speak very highly of me, and they always have. I've been working on this as soon as they told me of the issue... today he told me there might still be a problem with it, and i bet he told me 5 or 6 times not to mess with it today and to wait till next week sometime. But i immediately started working on it and spent the better part of thanksgiving trying to troubleshoot it. This is on the heels of working till 3 in the morning last week repairing a busted water line so that his kids would be able to take showers before school the next day, even though he told me to wait until the next day. Also on the heels of spending 3 or 4 days cleaning out a 40 foot culvert under his driveway that had become entangled with roots, which was starting to cause a water backup.

And as far as your 'im sure you would expect the rent to be paid on time, no excuses' line... that couldn't be further from the truth. I have a habit of letting people pay the rent late because i guess im too soft to tell them to hit the bricks. Most of the time it works out ok, but it's cost me about $1000 over the past 2 years... thankfully some of which is slowly trickling in, but a good percentage of it will never be recovered. As a matter of fact, in this particular house the family currently owes me around $300 from the pro-rated move in fees because i told them i would wait until after the holidays if it would help them out... of which they were very appreciative.

Sorry, but after a very trying day of dealing with several issues, in addition to this mystery water heater problem, im really not in the mood for the implications you are making there. Stick it up around the corner, and save it for someone else.

Now if you'll excuse me im about to eat thanksgiving food for the first time today, and spend more time reading about plumbing problems.

Happy Holidays.
 
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Tireshark

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A possibility, but not a certainty, is if there's a defective valve somewhere (some single-handle valves can do this), the hot and cold are crossing over internally, diluting the hot output. The water will take the path of least resistance, and the kitchen or other points may not be affected (could be the problem in itself). Try turning off the hot supply at each fixture and run your test. IF you get more volume, then start opening up the hot supply one-by-one to isolate it to the culprit. You only need to do that with single handle faucets. This is an internal leak, and may not actually leak out.

Check the gpm out of the showerhead while you're at it. Someone may have removed the restrictor (some have that, some just have a hard restriction built-in but sometimes, people drill them out). Federal mandates are that it should not flow more than 2.5gpm, and there are some decent designs that will provide a nice shower at less than that.

Thanks jad. There are no single handled faucets in the house, so i'm assuming that would eliminate the possibility of what you are talking about.


I let the water heater fully heat back up after i did the bucket test at the tub, and i did the same test from the kitchen faucet. This time i got around 22 gallons of hot water before it started cooling down. Probably 24 gallons were delivered at what i would consider enough for a warm shower. This is more than the 15 or so gallons i got from the tub doing the same test.

I dont know the specifics of this, but i would imagine that if i only have a 30 gallon tank, and if I'm opening up the hot faucet at the kitchen all the way, that i wouldn't get a true 30 gallons of hot water anyway, because the new water entering the tank would be diluting it at that point. If that's true, then it would appear that the tank is operating at normal levels. Would be interested to hear if my assumption is correct here.

I'm probably going to repeat the test tomorrow at the tub, and at the kitchen faucet, just to confirm that that 10'ish gallon difference between those two locations is legitimate.

I'm just trying to make sense of things as i troubleshoot the issue.... and since im the biggest idiot i know, sometimes it takes a little longer. It's certainly possible that it will require a new water heater, and i have no problem if thats the case... but i want to exhaust as many of the possible causes as i can before i do that, in an appropriate timeframe.

If i end up having to replace it, then hey at least i gained some more knowledge about how these systems works Heck, a week ago i had never even heard of a dip tube before.
 

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It could be that a flush would help a crud problem. To flush, put the WH in vacation mode. Run a hose to a drain and drain the water heater. You need to open a hot water tap to let air in.

Then turn on the water back on to the WH for a few seconds. That way the dip tube will spray water at the bottom. Let it drain. Repeat.

Then restore the WH to normal.
 

Tireshark

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Thanks reach4, i'll probably do that tomorrow. I cant remember if i've flushed it in recent years... i think i drained it for something about 3 years ago, but cant remember for sure if i did or not... i know it hasn't had a proper flushing in 10 or more years, so it certainly wont hurt anything.
 

Terry

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Twenty two year old gas water heater.
I would not be spending too much on that. They typically fail in 10-15 years. Some go more than 20 years. Not many.
 

Tireshark

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Yeah i dont really plan on spending anything more than the $10 i dropped on the dip tube, just trying to make sure the problem is actually the water heater before i replace it. I hate spending money to replace functioning parts, haha.

One time one of my front brakes acted like it was locking up on my truck, and my buddy (who knows a lot more about cars than me) immediately said it was the caliper, so we went and bought a brand new one... a few days later it started locking up again... in the end it was just a kinked $10 brake line. That's what i get for not doing research on the web first, lesson learned.
 

Jadnashua

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You're lucky to get 75-80% of the tank capacity out as fully hot before noticing it dropping off in temperature. Depends on how hot you've set the thermostat, and how cold your incoming supply water is. Keep in mind that at the shower, you're not typically using 100% hot water, you've got some cold mixed in (less in the winter because it typically gets colder, sometimes frigid).

As far as I know, single handle valves are the more likely culprits of cross-overs, but a hot water recirculation system or possibly a washing machine hookup could cause it as well. Sounds like the tank is doing its job, but as winter approaches, the incoming cold water will cool things off faster than in the summer...that may be the effect they are noticing.
 

Master Plumber Mark

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If you just install a larger heater your problems will go away....
at the very least do a 40 gallon rheem heater.... 30 is just too small for 2
people to deal with especially if they are female roommates

Forgot to mention ....the water heater is 23 years old...
In human years that is like 85 .... so it is not gonna run any marathons
anytime soon

If you must squeeze a few more years out of it I suggest you flush it out,
install a new gas thermostat and burner assembly on it , change the anode
rod and maybe check the baffle in the chimmney for stoppage... You could also
throw a water heater blanket on it for better efficiency........

Doing all that is cheap
 

Tireshark

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If you just install a larger heater your problems will go away....
at the very least do a 40 gallon rheem heater.... 30 is just too small for 2
people to deal with especially if they are female roommates

That's interesting, considering that there hasn't been less than 4 people in that house in the last 7 years, and not a single family has complained about not having hot water to me. Heck i doubt that place has ever had more than a 30 gallon tank in it since it was built in the 60's, and a lot of happy families have grown up in it.

Look guys, i get that if you are running out of hot water too soon, a larger tank will fix that problem... i mean, that isn't exactly rocket science. But as i have pointed out several times in this discussion, a new water heater is not going to fix cross connected lines, or a bad mixing valve, or the washing machine screwing things up, or something else screwy going on.

I appreciate the extra advice im getting, and i would probably say some of the same stuff if i was in your shoes, but from my point of view i think there is a possibility that the problem might be something other than the water heater, or possibly in addition to having an old water heater. The biggest reason for that is because the tenants told me they had no problems with the hot water when they moved in, until about 2 weeks ago when all of a sudden they started running out. Also, the problem started only days after i replaced a handle cartridges, although i imagine that what i did would not have affected the hot water output.

Obviously a brand new, larger water heater would improve the amount of hot water delivered... but im still going to try and troubleshoot this thing... especially while all of their kids are gone to their grandparents houses.

If you must squeeze a few more years out of it I suggest you flush it out, install a new gas thermostat and burner assembly on it , change the anode
rod and maybe check the baffle in the chimmney for stoppage... You could also throw a water heater blanket on it for better efficiency........

Thanks for those tips. Baffle is clear, and i'm going to flush it out in a few minutes. To me it seems like the thermostat is working okay, because it comes on about 20 seconds after you start running the water, and it gets scalding hot on the highest setting. I assume that the entire tank is being heated properly before it shuts off, but i dont know if there is any way to actually test that or not.
 

Reach4

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Look guys, i get that if you are running out of hot water too soon, a larger tank will fix that problem... i mean, that isn't exactly rocket science. But as i have pointed out several times in this discussion, a new water heater is not going to fix cross connected lines, or a bad mixing valve, or the washing machine screwing things up, or something else screwy going on.
If you turn off the supply valve to the heater but you still get water out when you only turn on a hot valve, that would seem to me to tell you there is crossover.
 
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