5 Ways to Fix Low Hot Water Pressure
Our house is at an age where things are starting to break. So when I turned on the water and had low hot water pressure, I knew something was up. Here are the reasons for low or no hot water pressure in your house.
What Causes Low Hot Water Pressure?
The most common causes of low hot water pressure are hard water scale build-up in the lines causing a blockage in the line that prevents water flow from decreasing in pressure, clogged plumbing, or an issue with the shutoff valve or the meter valve not being completely open.
When you have no pressure from hot water, it could be something simple or something more urgent, and it’s best to figure out which one it is…quick!
Water Valve Issues
Understanding how the hot and cold water system works in your house is a worthwhile thing to know. Your water will come either from the city water main supply or if you are on a well from the pump. The water comes in from one central point and will have two separate valves, a water main shutoff valve (outside the house) and a water meter valve (inside the house on an outside wall).
If you have had plumbing work done recently, then the main shutoff valve may have been turned off so that the plumber could do his work. Check to see if the shut off valve is only partially open; this could be the reason for your low water pressure in the house. This would be for both your hot water and cold water as it controls the inflow of all water coming into your home.
This is the next place you should check is hot water faucets to see if they are clogged. This is a common issue; items like rust, sediment, calcium, and other deposits can build up on the faucet or in the lines themselves.
If it is the faucet, the problem will be localized to one or a few different faucets that will have build up. This is often the case if you have hard water and haven’t used a water softener.
The good news is that having hot water with no pressure on a single or few sinks means that it’s a clogged faucet and likely not the lines themselves. Clean the limescale, mineral deposits, and other debris out of the faucet head and see if your hot water pressure increases.
If it’s not that, it could be a leak in a plumbing line. Inspect under the sink to see if there are any leaks.
Over time pipes and water lines will need to be replaced. We recently had to fix a leaking flexible hose under the sink because our wifi water sensor notified us of the leak. Those leaks can cause a lot of damage to a house.
If your home is older and has old steel pipes, there could be some corrosion on the galvanized pipes that are restricting the flow of water from your hot water tank.
This is an issue that doesn’t show up instantaneously; rather, it slowly builds. As the pipes get more corroded and scale builds up, the water pressure gradually slows down.
This is one or more dire cases of low water pressure in the house because it means the pipes are causing the issue of low pressure and need to be replaced. This can be an expensive upgrade, and the old copper pipes will need to be replaced with newer plastic pipes (or copper if you prefer).
If this is the case, you will need to contact a plumber. The plumber will remove the corroded steel, take it to a scrapyard near you and replace it with the right piping.
Leaking or Busted Pipes
This is the worse one and needs to be dealt with quickly. If the water pressure has suddenly dropped in the whole house without other cause, you could be dealing with a leaking line or a broken pipe. You want to identify this quickly because it could result in massive damage and including wood floor water damage.
In this case, you will want to inspect the walls and floors where the pipes run. If you have a basement, you can check the ceiling to see if there are any water spots and look for any wet spots. Check to see if your hot water tank is leaking from the bottom. This can cause water pressure issues too. Once you can see where the water leaks are coming from you will need to stop the flow.
You will need to immediately shut the main water supply line (this turns off the water to the entire house) and contact a plumber in your area. This is the only real solution to busted plumbing lines and it needs to be addressed immediately.
Related: What to do if you have wet carpet in your basement.
Other People Using Hot Water at the Same Time
This happens to us once in a while when a few of us are showering at the same time or if we are running multiple appliances and having a shower. There is only so much water that can flow at any one time. If this is the case, you can dismiss the other issues. But if it persists, it’s likely there is a larger issue.
If everyone in your household tends to wake up and get ready at the same time in the morning, causing low hot water pressure in the shower heads.
This may be the culprit. However, if the low hot water flow is occurring consistently throughout the day, then it likely one of the other issues mentioned above. Try showering at a different time of day. If you still have low hot water pressure from the shower head, it’s likely one of the previously mentioned issues.
What If The Hot Water Pressure is Lower Than Cold Water
Is the hot water pressure low but the cold water pressure good?
If your hot water pressure is low, but the cold water pressure is fine, it could be that the hot water heaters’ shut off valve is partially closed. Inspect the tank and the valve to see if it is completely open.
If that is not the case, it could be a clogged line coming from the hot water tank that has had build-up or corrosion.
Another issue could be the pressure regulator issue. This regulates the pressure in the hot water supply lines and if you have a faulty pressure regulator you will need to replace it.
To see if you have a malfunctioning pressure regulator you can use a pressure gauge on an outdoor tap and run the water to see if your water pressure is testing in the right range. Plumbers recommend the pressure be in the 52-75 PSI range. We keep ours at 60 PSI.
Clogged Hot Water Heater
Another reason for lower hot water pressure is that your water heater may have a build-up of sediment inside the tank, causing it to have lower hot water pressure.
As cold water comes into the tank, the water heats, and natural sediment and mineral deposits fall to the bottom over time, causing build-up in the tank. If this is the case, you can hire a plumber near you to come and flush the water heater and fix the issue.
Clogging hot water tanks is very normal for areas with harder water.
What if there’s low hot water pressure in the tub and shower only?
If there is low hot water pressure in your bathtub and shower only, it will either be a leaky pipe, a clogged shower head or bathtub faucet, or a clogged line that goes to both. You will need to inspect all of these to determine which one it is and if you can fix it or call a reputable plumber. Take a look at the hot water supply lines to see if there are any visible issues.
Final Thoughts on Low Hot Water Pressure
We hope we have answered your question, “How do I fix no hot water pressure?” If your hot water pressure is suddenly low, it’s likely a change that has taken place from a clog or a leak somewhere, whereas if it’s an issue of lower water pressure over time, it’s likely due to build-up.
After inspecting and trying a few things, if you cannot fix the hot water pressure, it is best to contact a professional plumber and have the issue looked at.