the hot water, it goes fast.

December 5, 2008 6:50 PM

Plenty of hot water for a shower in the summer, not so much in the winter. Can I do anything about it?

I'm guessing it's because the water coming in is colder, but I'd really like to do something, anything. The length of shower I can take is easily half the time I can when the weather is warmer. The water gets very hot, but just not a lot of it.

side note: I've been told I should be using a blanket/cover of some kind around the water heater for efficiency sake, will this help any with length of time? i can't imagine it would make much difference and I think the tank is too close to the wall to wrap around anyways.

Any suggestions!?

posted by striker to home & garden (20 answers total)

Tankless water heater?
posted by ZenMasterThis at 6:59 PM on December 5, 2008

You should consider the path the hot water takes through the house. We insulated the hot water pipes where they run through the basement and paid a little more attention to the heating of the first floor to greatly improve our upstairs hot water.

We have a tankless heater, so once the heat is right, it can go on as long as you care to shower.
posted by advicepig at 7:02 PM on December 5, 2008

Wrap it with reflective bubble wrap.
posted by hortense at 7:46 PM on December 5, 2008

Have you tried turning up the thermostat on your water heater? If your hot water is hotter, you will use less of it and thus it will last longer. If you have young children, this might not be a good idea, since the hottest water from a hot water heater can scald.
posted by marsha56 at 8:04 PM on December 5, 2008

2nding turning up the thermostat. We turn it up in the winter, down in the summer. Go in increments of 5 degrees until it seems right. (You could do this in combo with other things like better insulation.)
posted by jay dee bee at 8:21 PM on December 5, 2008

Insulate, insulate, insulate. You can get foam tube insulation, with sticky to make it stay where you want, in 6' lengths at Home Despot or Lowes.

Something else to consider: do your hot and cold pipes run right next to each other? Like, touching? THe colder "cold" water could be cooling off the hot water. We get it all the time in underground pipes in commercial buildings, especially those that have been built during the winter.
posted by notsnot at 8:29 PM on December 5, 2008

Yeah, insulate your pipes (that you can reach), and look for areas where they may be exposed to colder air and consider sticking a batt of insulation against the outside wall there. Many older houses have no insulation in the basement walls below the sole plate marking the first floor.

And there are water heater insulation blankets at any good hardware store.

But if you are noticing less hot water, there is always a chance that one of your heater elements has failed. There are two, and if the top one fails you get half as much hot water as usual, or if the bottom one fails you get water half as hot as usual (because the water circulates), or a spike in energy units if it can keep up with usage.

You can measure the temperature at the faucet and see how close it is to the thermostat setting (120 degrees is recommended for scalding safety and energy savings nowadays, but 140 is a common higher temp that they often come set to at the factory).
posted by dhartung at 11:52 PM on December 5, 2008

If your water heater is more than 5 years old, you could very well have a corroded fill pipe.

Cold water comes in from the top of the tank, but it passes down the length of the tank through a long pipe so that it comes out right at the bottom inside next to the lower heating element. As you take a shower, the cold and hot water don't mix very much inside the tank, and you can get nice hot shower until the boundary layer between the cold and hot reaches the top of the tank. Then you have to wait for the entire tank to get hot again. This means that the amount of hot water you get in your shower should be relatively insensitive to the temperature of the incoming water in a properly functioning tank.

But if your fill pipe is corroded, cold and hot water mix at the point of any hole in the fill pipe (it will come out there because the pressure is lower than at the bottom of the tank) and you only get really hot water until that layer reaches the top of the tank.

The fact that your water starts out very hot, and the tendency of the cold and hot water not to mix if the cold comes in at the bottom the way it's supposed to (cold water is denser, so once it's at the bottom it stays there) indicates to me that your fill pipe has problems.
posted by jamjam at 12:11 AM on December 6, 2008

2nding the check your heating elements - when I bought my current place there didn't seem to be a lot of hot water to go round but I figured there was two of us so maybe it was just a matter of too small a tank. But then the housemate left and there was still barely enough hot water for a shower and then that started to feel cooler and cooler. Turns out one heating element hadn't worked in the time I'd lived there and the other was about to die as well. Two new heating elements later I have enough hot water for self and any guests and to do the dishes and then some.......
posted by koahiatamadl at 1:43 AM on December 6, 2008

I second or fifth or whatever the recommendation to insulate your water heater as it will save you energy. However, I don't think it will do a thing to help your cold showers. The heater regulates itself to stay a constant temp and it will do this regardless of insulation. Heat loss through the sides is pretty low, but since it is occurring 24/7 those losses add up in dollars. The real key is to raise the temperature (but not if you have young kids about). Of course raising the temperature of the tank only increases your heat loss through its walls (the heat loss being proportional to the temperature difference between the water inside and the surrounding air) making that insulation blanket all the more useful. Many utility companies will do the wrapping for you for a small fee and sometimes for free.
posted by caddis at 4:15 AM on December 6, 2008

Have you also looked at the size of your tank? Maybe it is undersized?
posted by saucysault at 4:45 AM on December 6, 2008

Wow thanks for all the suggestions. I'm still reading through them all and going to investigate this with a thermometer and add lots of insulation.

My only thing to add is that we've noticed this pattern for two years - plenty of hot water in the summer, not nearly as much in the winter. If it functions fine in the summer after having the issue in the winter, could it still be a heating element or fill pipe problem?
posted by striker at 5:12 AM on December 6, 2008

If it functions fine in the summer after having the issue in the winter, could it still be a heating element or fill pipe problem?

Yes, as their effects might not be felt as drastically in the summer, but the more likely situation is just that you need hotter water in the winter because your cold water temperature has dropped. It's cheap and easy to turn up the heat in an attempt to solve the most likely problem and if that doesn't work then look into the other possible causes.
posted by caddis at 5:26 AM on December 6, 2008

Water heater blankets do work, but probably won't help your situation. They are money savers, keeping heat inside the tank and allowing it to cycle less often to maintain the set temperature of the tank.

In your case, I think the other posters are right- either it's an issue where colder water is coming in, and the heater can't keep up, or the heater is putting out hot enough water, but for some reason, it is getting colder as it travels up to the shower. Or a combination of the two.

Depending on the cause(s), the solutions are already listed- insulate the hot water pipes as best you can to keep hot water hot, and investigate whether the hot water heater is broken or simply doesn't have enough BTUs to do what you are asking.
posted by gjc at 6:07 AM on December 6, 2008

Regarding the "turn up the temp" suggestions.. be careful about this if you have small children that could burn themselves with too hot water....
posted by HuronBob at 7:40 AM on December 6, 2008

It's possible that you are losing heat between the heater and your shower, but that still is not likely the cause of your cold showers unless you have an extremely long run. How much water is stored in the pipes, a gallon or so at best, versus in the tanks, many, many gallons. You would quickly use the cold water, and even the cold pipes would only affect the next few gallons. To test, run only hot water, no cold at all and see what temperature you get from the faucet after a few minutes. If it is lukewarm then suspect the pipes etc. If the water comes out hot (and you seemed to indicate that in the post) then you are not losing temperature in between the tank and the shower. If it starts out hot (or gets hot within a minute or so) and then quickly gets lukewarm then I would suspect a cold fill problem. You should be able to use at least half of your tank without the water going lukewarm and if not then you likely have a cold fill problem. If you really wanted to be anal you can start measuring water volumes etc., but that seems like overkill.
posted by caddis at 7:47 AM on December 6, 2008

What's your heat? If you've got hot water radiators for heat, you could also have a problem with more hot water being needed by the system in the winter and not in the summer.

(We had/have problems like this, and one solution was to not have the heat turn down at night, because it was too hard on the system to have the large change in temperature to try to deal with.)
posted by leahwrenn at 8:30 AM on December 6, 2008

How old is your water heater? If it's more than 10 years old and you haven't been (most people don't) maintaining it yearly by having it inspected and serviced, it may just be old and need replacing. This was what happened to me a couple of years ago.
posted by kalessin at 9:24 AM on December 6, 2008

I would guess the lower heating element is possibly out in your water heater. After not using hot water for a while (an hour or so), go to your water heater with a small pan to catch some water. There will be a release valve on the bottom of the water heater, usually in the shape of a outside hose faucet. Open that faucet just a little to let some water out into the pan or tray, and feel that. It should be very hot. Not lukewarm, hot.

If the water at the bottom of your tank is cold, then you have a few steps to take.

1. Replace the bottom heating element. This means turning off power to the water heater (very important), turning off water coming into the water heater, and draining all water through that valve at the bottom. You can use a hose attached to the valve to drain it into a nearby tub, out a window, etc. Make sure you have an air gap - which means opening faucets in the house, and/or opening the safety release valve near the top of your water heater on the side. Once the water is drained out, you can unscrew the bottom heating element and replace it with a new one. It will likely be covered in nasty greenish flakes (hard water deposits), and the long term solution is to use a water softener.

2. Once the bottom element is replaced, fill it back up first, then turn on the power. Let it heat up for a while, at least a couple of hours, and then you can test the water at the bottom of the tank again. If it is the same problem, the thermostat might need replacing. For this, you just need to cut the power and replace the thermostat near the bottom element.

3. If these fixes together won't work, then your best bet is to call someone to come check it out (or if you don't feel comfortable doing the work yourself, make that call first - I don't blame anyone for not jumping at the chance to work with water and electricity at the same time). If you go to your local hardware or plumbing store with the company name and model number of your water heater, they should be able to find out what element and thermostat you need.
posted by shinynewnick at 12:12 PM on December 6, 2008 [1 favorite]

I know this is an old thread but FWIW, I had the same problem as the OP and assumed it was the cold winter plus uninsulated pipes. Then my gas water heater sprang a small leak, plumber came out to replace it commented did I know the existing heater was over 15 years old? Uhmmmm, no, didn't notice.

Now, same house, weather outside much colder, same uninsulated pipes, showers work fantastic. So I vote for leaks in the cold water fill pipe allowing for a mixture of hot/cold water higher in the tank (at least in my case).
posted by forthright at 12:39 PM on January 25, 2009