Hot Water Downstairs But Not Upstairs? Here’s Why

If you have hot water downstairs but not upstairs, I’ve got good news and bad news. The good news is twofold: first, it’s likely an easy fix. Second, we’ve already covered a very similar issue! Now we’re going to tackle the issue to get your hot water flowing everywhere in your home. No more cold showers for you!

The most common causes for hot water downstairs but not upstairs are the valves, corrosion in your pipes, and distance from the water heater.

Let’s get into it, shall we?

Top Causes for Hot Water Upstairs But Not Downstairs

Let’s begin by taking a look at the easier fixes before we get into the spendy stuff, yeah? After all, there’s no sense in making big fixes when a ten-second one does the trick, right?

Valves

This is an often overlooked cause of hot water only coming to one section of the house. It’s common practice with most plumbers to install a valve (like the ball valve pictured above) in water lines leading to bathrooms. This allows them to turn off the water to a single part of the building and make repairs more easily than if they had to turn off the water to the whole home.

Sometimes they get bumped by accident, leading to the hot water either turning off or being less readily available. To check if this is the issue, you only have to do a couple of easy things:

  1. Locate the valve for the tap in question. Generally, these valves are located beneath a sink (like a bathroom sink).
    1. If you can’t find it, follow the pipe from the water heater to your bathroom and it should be pretty clear to see. Keep an eye out for a temperature-regulating valve while you’re doing this, they’re not standard practice but are installed in some homes.
  2. If you have a temperature-regulating valve, this is likely the cause. Ensure it’s fully opened with a flathead screwdriver and test your water.
  3. If it’s just a shutoff valve, simply turn it so it’s fully open and test your water.
    1. If you notice that the valve puts up a fight while turning, you may need to replace it. While you can do this yourself. I recommend that you call a professional to double-check that this is the issue before your proceed.

Faucets

Another potential cause of a lack of hot water is a temperature-regulating faucet. While they’re not super common, this is a possibility to look out for. Newer homes (and renovated old homes) both make use of these – it’s essentially a stop-gap measure designed to prevent a faucet from getting so hot it can burn you.

To see if you have one (or adjust it), do the following:

  1. Check the temperature coming from your boiler or gas heater, and compare it to the hottest water you can get in the faucet in question. If it’s slightly (~15 degrees) cooler, it’s likely you have a temperature regulator. If it’s drastically cooler, this is likely not the issue.
  2. After turning off the water, remove the center cap from the faucet. This will reveal the hot water stop and faucet stem.
  3. Entirely remove the hot water stop with a screwdriver and reactivate your water. Re-check the temperature coming from your faucet – if it’s improved, this was the cause of your issue. If it’s too hot, you can either replace the stop or adjust it to see how things change.
  4. Keep making adjustments until it’s in the “Goldilocks” zone – not too hot, not too cold, but just right.

Distance From the Heater

This is something that a lot of people don’t consider. In order for you to get hot water anywhere in your house, the water needs to travel through pipes. If you only have a single water heater and a large house, it’s very likely that the water is just cooling before it reaches its destination.

Take a look at the path your pipes take – do they travel through a crawlspace or along the side of the house? It’s possible that they’re just not insulated well enough (or simply go too far) to prevent outside temperatures from affecting the water inside.

You can either insulate your pipes or invest in an auxiliary on-demand water heater that’s closer to your bathroom. Neither is going to be cheap, and the latter option requires that you find space for the second heater – but boy will it be worth it to have steamy showers again.

Corroded Pipes

This is an especially likely issue if your home is old. Galvanized steel pipes will absolutely corrode from the inside and restrict water flow. The more they build up rust and mineral deposits, the less water will be able to flow through them. And the worst part about this is that hot water speeds up the rate of corrosion.

While it’s less common, copper pipes can also corrode. Unfortunately, if this is the cause, you’ll need to replace all of the corroded pipes. And that’s definitely not a job for the average Joe – you’re going to want a good plumber for this.

Leaks

This is another cause of a lack of hot water on one floor that nobody wants to hear. If you’re noticing that a single faucet is struggling to provide hot water, examine its path. If you find even a hint of moisture, it’s time to get your pipes inspected. Often a burst pipe will first present with a drop in water pressure and poor temperature regulation – so keep an eye out.

Test the water pressure of your faucets with a pressure meter. If it reads lower than the pressure at your water heater, there’s a leak somewhere along the line.

Final Thoughts

There are a lot of things to look out for when it comes to your home’s water system. If you’re noticing that you’ve got hot water downstairs but not upstairs (or vice versa), go through the above steps to locate the issue. It could be something as simple as a valve accidentally getting turned, or even a temperature regulator you didn’t know existed.

If those aren’t the causes, it’s time to look for major issues. Whether that means you’ve got a leak somewhere along the line, or corrosion in your pipes, these are both fixes that will require a professional assessment to solve. You could also simply have the heater too far from your upstairs faucets – this can be fixed with pipe insulation or an auxiliary heater. One way or another, this list will have your showers hot and steamy again in no time.

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About the Author Harry Thompson

Involved in home renovations throughout his life, Harry is an expert in everything to do with home and garden DIY. In his spare time, he enjoys cooking and tending to his garden.