I just want a hot shower!
December 12, 2013 7:58 AM   Subscribe

We have a hot water problem and I would love to have an idea of what the problem and solution is before wasting a bunch of money on a plumber.

So we have a plumber, and he's good, but he's not cheap, so I was hoping you guys could trouble shoot with us before I call him. So we have hot water, it's just... not enough and inconsistent. So in the morning, the first shower is... not very warm. The second shower used to be nice and hot. This morning, alas, not so much. It was warm, but not hot. So basically, sometimes we have nice hot water but it seems to need to be primed to work correctly and it might be going downhill. We are assuming we need a new water heater. Are we right? And is that something we should buy before bringing the plumber in so we can only pay for one visit? Or are we going to want him to come by first?
posted by katers890 to Home & Garden (22 answers total) 1 user marked this as a favorite
What kind of hot water heater is this? Electric, gas?
posted by Monday, stony Monday at 8:04 AM on December 12, 2013

Are you finding the same problem with hot water from the taps?
posted by LN at 8:06 AM on December 12, 2013

Couple of things to check -

Any chance someone has played around with the thermostat on the water heater? The one on ours is kid-high, and the little dial is just the right size for playing around with. I duct-taped it in place and drew a scary frowny face on it to keep small hands away.

If it's a gas water heater, can you see the pilot light? Is it coming on and off like you'd expect?

As mentioned above - is it just the shower? Or are all the taps screwy w/r/t hot water?

If you live near a big-box store, you can buy a water heater and pay for installation. You may or may not get a better deal than you would from your plumber, but it's an option worth checking.
posted by jquinby at 8:07 AM on December 12, 2013

Do you have a traditional hot water heater with a tank or a tankless hot water heater?
posted by mskyle at 8:08 AM on December 12, 2013

Typical water heater lifespan is around 8 years.

For electrical water heaters, it's not uncommon for the heating elements to become corroded and degrade into uselessness; there are two elements, one at the top of the tank and one at the bottom, and they extend from the side of the tank into the water.

If you have gas, well, I know nothing about gas heaters specifically, but if replacement is the way to go, then this may be the time to upgrade to a high-efficiency gas heater, which heats water very rapidly and on-demand. Your plumber can advise you on whether you have the prerequisites (ventilation for the gas burner, electrical power for pumps and maybe ignition, and whether they are suitable for your water consumption needs.
posted by Sunburnt at 8:09 AM on December 12, 2013

I have had this problem before with an electric hot water heater that had two heating elements and one was out. You'll need to let us know what general type of hot water heater you have and how much access you have to it (because yeah I'd check the thermostat first and foremost) for people to give you other ideas. A plumber can bring along a new hot water heater but it might be cheaper to purchase one yourself if you need one.
posted by jessamyn at 8:10 AM on December 12, 2013

How old is the hot water heater? If it's relatively new, you may just need a new heating element. Pretty common if you have hard water.

Before you buy a new hot water heater, you'll want to see if there are any federal, state or utlity rebates. We bought a tankless hot water heater and by the time we got all the rebate money, it was pretty close to free.

You may need your plumber to come and diagnose the problem, then you can decide what to do from there.

Not a lot of pumbers will deal with a tankless hot water heater. I've heard from many of them that they're unreliable, or not as cheap as you'd think, etc.

What I found was that tankless is AWESOME, continuous hot water.
posted by Ruthless Bunny at 8:11 AM on December 12, 2013

Depending on the state and age of your house, and the state of your finances, it might also be an opportunity to consider an alternative water heating system, like the aforementioned a tankless water heater, or a heat pump water heater, especially if the heat pump can also give your cooling and heating.
posted by Monday, stony Monday at 8:17 AM on December 12, 2013

If it is your hot water heater, check to see if it is still under warranty. I had mine replaced last year simply for the cost of some bs stocking fee of $75. I did pick it up myself at the plumbing supply house so I could use my own plumber. It was easy as pie.
posted by JohnnyGunn at 8:25 AM on December 12, 2013

I had a similar problem a few years ago in my house. We had a tankless heater, and over the years, mineral deposits gradually built up on the interior of the heater, reducing the amount of heat that was transferred from the boiler to the hot water. We really noticed it when the outside temperature dropped, especially since our upstairs shower is on the opposite side of the house from the boiler.

Our solution was to replace the tankless heater with an external tank that's heated via a coil going to the boiler. With the new setup, the same water is recirculated between the boiler and the water heater, thus limiting the mineral deposits.
posted by brianogilvie at 8:36 AM on December 12, 2013

Answers to questions asked so far, sorry for the lack of detail in the original question.

1) It's a standard gas water heater (ie. not tankless)
2) It is not new, when we bought the house, the inspector did not that the pilot was a bit... less than perfect, and noted that we'd likely need a new heater eventually, but it was functioning fine at that time, which was... 5 years ago now.
3) Similar problems from the taps, though I notice it less being as it is not a shower : ) But my MIL, who lives downstairs, noted she didn't have great hot water for dish washing the other day.
4) Heater and temp everything is out of the way from little kids messing hands. And when we get hot (instead of warm) the temp is fine.
5) The heater is in the basement and vents into the house, not outside, which is not ideal, we know, but nothing that is going to change.
6) Finances not super great (hence desire to save some on plumber), but if it was worth it, I would consider changing out the system for something new and greater, but right now, I mostly just want a hot shower : )
posted by katers890 at 8:41 AM on December 12, 2013

Easy peasy (maybe...)

Hot water heaters get their cold water delivered to the bottom of the tank through a thing called the dip tube and they deliver their hot water from the top of the tank. Dip tubes are plastic and sometimes fail. They cost a couple bucks.

When they fail the cold water mingles with the hot at the point where the hot water exits the tank. The result is (usually) good hot water for a very short time and then warmish water.

Changing a dip tube is pretty simple. Here's a link to some DIY videos.
posted by bricksNmortar at 8:47 AM on December 12, 2013 [1 favorite]

5) The heater is in the basement and vents into the house, not outside, which is not ideal,...

What? That can't be right. That would be a potentially life threatening situation.
posted by bonobothegreat at 8:52 AM on December 12, 2013 [6 favorites]

Gas boiler venting inside the house sounds completely wrong.
At the very least get a carbon monoxide detector and put it in the basement. And if it goes off DO NOT GO INTO THE BASEMENT - the CO will have pooled down there.
posted by EndsOfInvention at 9:01 AM on December 12, 2013 [2 favorites]

I had an unvented gas water heater in my kitchen, and lived. ymmv.

I usually run the hot water before I take a shower, until I hear the furnace/ water heater kick in. If there's no demand for a while, it seems to go to sleep.

I'd ask the gas company about the payback period for a more efficient unit, 'cause it might be worth changing it out.
posted by theora55 at 9:05 AM on December 12, 2013

What? That can't be right. That would be a potentially life threatening situation.

There is a good chance that at the point you have to get this fixed (if it's not something that is simple) a plumber may not be able, legally, to replace your hot water heater with one that vents in this manner. This was the situation in a house I owned. Gas hot water heater vented to the barn which wasn't quite as dangerous but still a terrible idea. It eventually failed and my plumber would not replace it with one that vented the same way, basically couldn't, it wasn't legal. I wound up replacing it with an electric hot water heater (which is an option for you as well) which doesn't have the same venting requirements and was a pretty simple fix, though not cheap.
posted by jessamyn at 9:06 AM on December 12, 2013

If you end up being in the situation Jessamyn describes, there's a chance you could save a bit of hot water by installing the electric heater, which doesn't need a gas connection, to be more central relative to the outlets (showers and sinks), so you'd have less hot water cooling down when it's sitting in the pipes. It will depend on the layout of the house and piping, though.
posted by Monday, stony Monday at 9:15 AM on December 12, 2013

Re: the ventilation issue: It is legal, and we do have a CO detector there. Everything related to that was checked (by inspector, fire department, and plumber) when we bought the house and like I said, we know it isn't ideal, but it was standard when the house was built in the 70s and it is not something we want to change. Even if you don't believe me, just ignore this as a factor for now.

We can't move the location of the heater, it is where it will stay. Replacing it with electric is a possibility, but again, I'm generally looking for the lowest cost solution to the problem, and that cost includes longer term efficiency in terms of gas vs electric heating.

But it sounds like the general agreement is that the heater is the problem, and besides checking one or two things on our own, and deciding whether to do any major changes (eg. go tankless), just buying a water heater ourselves and having a plumber or the store install it is the answer. Thanks!
posted by katers890 at 10:07 AM on December 12, 2013

Re: the ventilation issue:

It may have been legal at the time, and the inspectors would all pass it under grandfather clauses. However, if you replace it, it may not be legal to keep it that way.
posted by tckma at 10:20 AM on December 12, 2013

It may have been legal at the time, and the inspectors would all pass it under grandfather clauses. However, if you replace it, it may not be legal to keep it that way.

Seconding this.

If you are going to replace it, you are going to have to take a punt on what relative gas/electricity prices are going to do over the life of the unit. You should look at heat pump electric as well as the usual immersion element heaters and of course gas.
posted by GeeEmm at 6:07 PM on December 12, 2013

Considering this is gas and your first shower at times is cold I'm seconding bricksNmortar that this is likely your dip tube. Some dip tubes are integrated into the heater anode and as they reach the end of their lives they'll get hole in them that will allow the cold water to mingle where it's not supposed to causing your symptoms.
posted by Mitheral at 7:39 PM on December 12, 2013

Another possibility is a faulty tempering valve. This is a little gadget that sits outside the heater, whose job is to mix a controlled amount of cold water with the hot water from the heater before it's delivered to the rest of the plumbing. The intent is to limit the maximum temperature you can get from any hot tap to a scalding-safe 50°C while still allowing hot water to be stored at a bacteria-unfriendly 65°C+.

Tempering valves are very simple thermo-mechanical devices, and if you have one that's built up an internal load of deposited crud, its thermostatic action might well have become sticky and unreliable. You might find that twisting its adjuster screw back and forth a few times and/or giving it a sharp rap with a small hammer is all you need to do.
posted by flabdablet at 8:28 PM on December 12, 2013

« Older Things are getting steamy - boiler exhaust safety?   |   I just got my masters in Biophysics and want to... Newer »
This thread is closed to new comments.