First off, I live in Phoenix, AZ. This is desert here. I live in an area where people mostly have natural desert landscaping rather than lawns.

Now, this will sound really odd to folks who live elsewhere, but the house I'm in now does not get "cold" water in the summer. I can literally shut off my hot water heater and take a shower just from the cold water coming in from the city water line. The so-called "cold" water temp is somewhere over 110 for most of the summer. It's fine for most of the rest of the year, just not from May thru Sept.

I've lived in different parts of the city throughout my life, and this is the hottest "cold" water I've ever had to deal with. I think a big part of it is because the ground in this area is quite rocky and sandy, not much solid dirt. And it's dry as a bone.

Where you've got a water main running under yards that have lawns that are watered regularly, the water seeps into the ground and cools the ground and whatever pipes are there. Hardly anybody in this area has lawns, certainly nobody along the route where my water main comes from.

Short of putting a 50 gallon water cooler into a fridge (the opposite of a water heater), I'm wondering if anybody has any ideas about how I might rig up something that could cool the water coming into the house by 20-30 degrees?

  • How much cooled water do you need to have available? How quickly does it need to replenish itself? (Think about recover time of hot water heaters—you use too much and have to wait for more) It seems like most in-home uses for colder water involve drinking (and brushing teeth). Just thinking about this, I personally turn on the hot far more often than the cold. – Tyson May 6 '18 at 10:51
  • Well, it's just plain annoying not being able to get "room temperature" water out of the tap. If it's a hot day and you want to splash some cool water on your face, or put some cool water on a washcloth to wipe your face or take off a layer of sweat, or just jump in the shower to cool down, you can't! I don't like "cold showers" but when it's 110+ outside, "room temperature" water is quite refreshing. Water coming out of the fridge at 38 degrees would require hot water to warm it up. But if the water out of the tap was even 80 degrees, it would be nice. – DPS May 6 '18 at 17:07
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    Are you sure that you do not have a cross-over problem? Do you have any older single handle Moen Faucets in the house? If you do replace all the cartridges. This may be the issue. – Paul Logan May 6 '18 at 17:41
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    Also just remembered another item that’s horrible for creating crossover, awhile back (15 years) in our area there was a plumbing company actively pushing (selling) hot water recirculation systems that didn’t require a return. Instead they put a valve under the sink to use cold pipe. The valve was thermal actuated and was supposed to close when it got hot.... those valves failed A LOT however, leaving both hot and cold hot everywhere even the toilet. Also can you ask your next door neighbor if they have a hot city water problem? – Tyson May 6 '18 at 18:50
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    As I said, the cold water temp is fine until the outside temp starts pushing 100, as it is right now. If there was a crossover problem, it would happen year-round, right? And I don't have any kind of recirculation. I kept the hot water heater on its lowest setting all last summer, and the gas bill was ridiculously low. – DPS May 7 '18 at 3:27

Very common in tropical Australia, not a big deal. The ground gets hot in summer and even though the street pipes are six feet underground the water can scald. Every summer we turn off the power to the hot water storage tank, it then becomes the cold water supply. If we use too much "cold" water the tank warms up. The house has an evaporative cooler and the tank is positioned inside the house and is cooled.

  • This technique could be enhanced with a very basic flat plate solar water heater -- if water is pumped through that heater at night it becomes a night sky radiant cooler instead! – Greg Hill Jul 31 '19 at 20:47

So I also live here in Phoenix since 2006. I always tell anyone back home, home being San Diego that the heat actually doesn't bother that much since if it wasn't so hot in the summer, then we'd be another California....Anyways what does really bother me is no cold water to rinse off at night before bed...My friends and family are always dumbfounded....But here's a solution I found....Get a large metal colander….Get a rubber/plastic bowl about half the size of the colander then freeze water in that bowl...find a way to hang the colander under the shower head...place the chunk of ice in that colander and let that really warm to hot water run over the ice and sprinkle through the colander down on you....with that cold water....It actually works...

  • Hello, and welcome to Home Improvement. Thanks for the answer; keep 'em coming. And, you should probably take our tour so you'll know how best to contribute here. – Daniel Griscom Jul 31 '19 at 15:41
  1. Exclude a crossover problem in the shower valve as described by @Paul Logan above. Test the temperature of the incoming city water say at an outside faucet.

  2. If the incoming city water really is 110 F, then make your own cool water (say 80 F) by the batch by putting enough ice into a bucket with 1 or 2 gal of water. Take a quick shower using a low flow shower head say 1 gal/min using the house (hot) cold water to get clean (less volume of water means less heating by the water). Then as a final cooling rinse repeatedly dip a small bowl into the cool water and pour it over yourself.

  3. Alternatively, get a camping shower and pour the ice cooled water into the reservoir and spray it over yourself as a final rinse.

  4. Get one of the old fashioned canvas water bags and hang it outside in the shade. Evaporation of water seeping through the canvas will cool the remaining water inside. Use that for the final cooling rinse.

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    Why would using an outdoor faucet eliminate crossover caused by a faulty valve? I would think to test for crossover in a faulty single handle cartridge the feed from or to the hot water heater would have to be closed off. – Tyson May 6 '18 at 18:43
  • I just thought that was a simple test which might be diagnostic if the problem was the crossover in the shower valve itself, and hot was only leaking over to the cold when the shower valve was on. (In some plumbing systems the take off for the outside faucets is before the takeoff to the water heater.) One other possibility is that there might be a faulty thermostatic mixing valve on the output of the hot water tank which is allowing hot water to get into the cold water supply. but I doubt this house would have that. – Jim Stewart May 6 '18 at 20:52
  • Hey, hey, I like the creativity! Look, it's not just the shower. The bathroom sinks and the kitchen sink have the same issue. And I have no single-handle valves anywhere. If I let the cold water run long enough, the stuff that was in the walls and attic get flushed out and I start getting the water that was in the pipes in the ground outside and finally from the water main. It's HOT. Uncomfortably so when it's over 115 outside. That's all there is to it. – DPS May 7 '18 at 3:31
  • So are you doing anything right now to get a more cooling shower experience? What kind of shower head do you have? – Jim Stewart May 7 '18 at 8:54
  • I'm not doing anything other than not using hot water b/c the "cold" water is plenty warm enough. It's just that it literally gets "too hot" at times during the summer. That's why I posted this, to see if anybody has any ideas about how to cool it down. – DPS May 7 '18 at 19:59

Is there any practicality of digging your own well to bring up water from deep in the ground? If you could do that then the water temperature would be closer to the average deep crust temperature of the earth.

Digging a well in most areas is probably limited to folks that have a certain minimum size of property. There are also many other local restrictions as well.

  • This house is elevated above the valley floor due to its location at the foot of a peak that tips 1500', and I suspect the depth to a water table might be quite a bit. But it's something to consider. (Everybody in this area has city water, AFAIK, but we have no sewer; we're all on septic tanks, if that says anything.) – DPS May 6 '18 at 17:15

Perform a search for "undersink water chiller". You will find products in the $ 200 - $ 600 range retailed by companies like Amazon and Home Depot, capable of chilling about a gallon of water per hour, and capable of storing 2 - 3 quarts of chilled water.


This is just an idea, I guess it would be a variant on another answer suggesting you use the hot water tank for cold water supply part of the year.

Most well systems use a pressure tank in the basement of the home, the well pump fills the pressure tank from the hole in the ground, and the tank supplies the water in the house.

You could install a pressure tank that's simply fed from the water company supply, and in turn supplies the cold water for the house. (You could bypass the pressure tank to supply the water heater.) The pressure tank would serve as a simple cistern or reservoir where the water cools to your basement's ambient temperature. I believe it would cool faster than the water heater tank because it's uninsulated, and you could leave it in place year round. This should not be that difficult of a plumbing job.

You could even conceivably bury the tank in your yard or in your basement floor for better cooling. I am pretty sure that 4' underground the temperature is pretty cool, but you could easily core drill a small hole down a few feet and run a temperature probe to see before you did all that work.

  • I'm located on the downslope of a "mountain" that a neighbor said was built by adding dirt above the bedrock. It's not very far down. – DPS Sep 6 '20 at 19:46

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