Showers commonly have a problem with temperature control. There is a pressure balancing valve and cartridge that controls the mixture of hot and cold water as it leaves the shower head. Frozen pipes, corrosion, and aging parts can affect how well this works.
There are 3 reasons why there is no cold water in your shower. First, check that the main water valve is not turned off. Otherwise, there may be an issue with the pressure balancing valve or mineral buildup or corrosion in the cartridge. In these cases, the part will need to be cleaned or replaced.
Discovering that there is no cold water can be stressful. Fortunately, a quick check, cleaning, or replacement part can solve this common issue relatively quickly. Read on to learn about what you can do and when to contact a plumbing professional.
Why Is There No Cold Water In My Shower?
There are a few common reasons why a shower has no cold water. Your main water valve may be turned off or there is a pressure balancing valve malfunction.
If there is a mineral buildup or corrosion in your pipes, this could affect water temperature as well. Blockages or leaking or busted pipes can result in low pressure or low amounts of cold water that travel through the pipes to your faucets.
1. Your Main Water Valve Is Turned Off
Water valves regulate the volume and flow of hot and cold water separately. If one of them is turned off, or even slightly turned, it will reduce or stop the amount of cold water that comes to the faucet.
If the cold water valve is turned off, then your shower is going to be very hot.
If the lack of cold water is only affecting the shower, then check the valve that is on the pipe that leads to your shower line to ensure that it is on. The handle or knob should be lined up with the pipe, facing the same parallel direction.
If there is no cold water for the entire house, then check the main valve, and turn it back on.
2. Pressure Balancing Valve Malfunction
A defective pressure balancing valve can affect the temperature of your shower’s water. This pressure valve is contained within the internal components of your shower’s handle that turns to control how much hot and cold water mix.
This valve is thermostatic using a balancing spool, temperature sensor, and moving ceramics to control the temperature and flow of water.
This sensitive component detects drops in pressure or uneven temperatures and adjusts accordingly to deliver consistent pressure and temperature to the user.
These internal components are subject to wear and tear and from mineral deposits, resulting in uneven pressure or temperature.
3. Your Shower Has A Mineral Buildup or Corrosion
Mineral buildup or corrosion within the pressure balancing valve or main pipes can affect the temperature of your water. Buildups can even cause blockages that greatly restrict the flow of water.
If you notice that the temperature or pressure inconsistency occurs while showering, you will need to investigate the cause.
If a leak or burst pipe is the cause, stop using all sources of water. Monitor your water meter for 2 hours. If the water meter changes without using any water in your home, you have a leak.
How To Fix No Cold Water In Shower
Your shower may not have cold water due to turned-off valves, faulty parts in the shower system, leaks, frozen pipes, or corrosion or mineral buildup in the system.
There are some common solutions that you can do before contacting a plumbing professional. These include checking for frozen pipes, making sure water valves are turned on, and replacing the pressure balancing valve in your shower system.
Read on for further information.
Check For Frozen Pipes
Pipes will freeze when the temperature around the pipes is below freezing (32 °F) in as little as a few hours.
When the water inside the pipes turns to ice, the volume of the water expands, restricting the flow of water, increasing the pressure of flow against the blockage, and potentially causing the pipe to break.
While interior pipes generally stay warm enough, if there is a power outage, these can freeze as the temperature of the house decreases.
Indoor pipes that run along exterior walls of basements, crawl spaces, and so on, are at greater risk of freezing as well.
Outdoor pipes (and connecting faucets) leading into the house without adequate insulation can also freeze.
Signs Of Frozen Pipes
Typically, you will know that pipes are frozen if the following occur:
- Frost accumulates on the outside of the pipe
- Restricted or no water flow
- Bad odors emanating from drains
What To Do
Waiting for pipes to unfreeze when temperatures climb can result in costly repairs. It is important to act fast. If you cannot find the frozen line, call a plumbing professional for emergency service.
If a pipe has burst, be aware of electrical hazards. Never step into pooling water.
- Leave faucets open to reduce the pressure in the lines. Cold water can melt frozen water, and it may help to loosen up the ice.
- Once you start warming up the pipes, pressure will increase. Keeping the lines open reduces the likelihood of a burst pipe.
- Use a hair dryer or a heating pad to carefully heat the pipe.
- Start this process by working at the faucet point and working your way down.
- Do this slowly to avoid a quick buildup of pressure inside the line.
- Turn up the heat inside the room that has frozen pipes using a space heater or heat lamp.
- This will slowly raise the ambient temperature in the space for an even thawing out.
- Never use an open or direct flame.
- Drain odors may continue to persist if they are trapped in the lines. If possible, open windows to eliminate the odors.
Prevention Of Frozen Pipes
Once the frozen pipe emergency has been alleviated, take preventive steps to keep this from happening again.
On days of frigid temperatures, leave a faucet open that can drip to prevent any pressure buildup.
If you have water pipes that go through cabinetry, leave the doors open on frigid days. This allows the air from the house to flow over the pipes, keeping them warmer.
Insulate your pipes using foam pipe insulation on both hot and cold lines.
Make sure you know where your main water shutoff valve is located in case of an emergency. This can protect your basement and other areas from flooding.
Why Is My Pressure-Balancing Valve Malfunctioning?
A pressure balancing valve can malfunction for several common reasons. For example, toilets use cold water, and if someone flushes it while you shower, it draws cold water away from the pressure-balancing valve.
Other issues, such as corrosion, mineral buildups, or an aging valve can affect the flow of cold water.
An updated replacement valve that controls and balances the flow better when toilets are flushed can be installed. Older homes tend to have valves that are no longer used in new installations.
The section below describes how to clean and replace a shower valve cartridge.
How Do I Replace A Shower Cartridge?
To address a shower cartridge issue you will need a few tools to dismantle the shower handle, remove the valve and cartridge, and then clean or replace it.
Read on to learn in detail about the steps to take.
Steps To Replace A Shower Cartridge
Gather tools and supplies before you start working.
These include the following:
- Replacement cartridge and valve (refer to user guide or contact or local hardware store or plumber)
- Towels or rags
- Small bowl to hold small parts
- White vinegar
- Soft toothbrush
- Groove-joint pliers
- Utility knife
- Waterproof caulk
- Plumber’s grease (non-petroleum based)
- Screwdriver
- Hex wrench (some models)
- String
- Tape
- Cartridge puller (special plumbing tool)
- Meter key (outside water main shut off, some styles)
- Meter wrench (some styles)
- Camera or scrap paper and pencil
Step 1. Shut off the main water supply
Shut off the main water supply. If you see an oval or rectangle lid outside your property, you can turn it off here using a meter key. Or, there may be valves that can be turned perpendicularly by hand as well.
If you have a valve box or turn-off mechanism inside your home, turn this clockwise or perpendicular to stop the flow of water.
Step 2. Cover the shower drain
Close and cover the shower drain to prevent any small parts, such as screws and the retainer clip from falling inside. Cover it with a towel, rubber, or plastic.
If you lose important parts down the drain, you will have to replace more parts, making your work more complicated and costly.
Step 3. Remove the shower handle
Each shower handle has different installation instructions. If possible, locate your user manual or do a quick search online for it.
Generally, you will use a screwdriver or hex wrench, turning it counterclockwise to remove the shower handle.
Remove any cover plates.
Score any caulking carefully with a knife to remove it completely.
Step 4. Memorize the inside assembly of the faucet
Use a camera or create a sketch of what the inside assembly of the faucet looks like. You need to know and remember how it is put together so that you can reassemble it correctly.
Step 5. Free the retainer clip
To remove the cartridge from the valve, the retainer clip needs to be pulled out. This very small piece can be easily lost inside the wall.
To prevent this from happening, pull a piece of string through the top of the retainer clip that protrudes from the valve.
Tape both ends of the string to the shower wall so that it does not fall free. This makes it easy to find this part when you reassemble.
Step 6. Pull on the valve stem to release it
Pull on the valve stem to release the cartridge. If there is corrosion, this may be difficult. Use a cartridge puller, as described in the next step, to assist you.
Step 7. Detach the cartridge from the faucet
Next, you can detach the cartridge from the faucet. Be careful to not pull it out with extreme strength or you can cause damage to the rest of the plumbing.
Use a special valve removal tool, called a cartridge puller, which lines up with the mechanism. Use the tool to twist and loosen the cartridge. Then a pair of pliers can pull it straight out.
Step 8. Dissolve any corrosion or mineral deposits
You can easily dissolve mineral buildup by using a Calcium-Lime-Rust (CLR) remover product or white vinegar by letting it sit in the solution for about 10 minutes.
Use a medium-bristled toothbrush to scrub it clean. Rinse clean with water.
If this does not eliminate all debris, repeat the process, letting it sit in the solution for up to 1 hour.
Step 9. Line the new cartridge and the inside of the valve body with the plumber’s grease
Reinstall the cleaned or new cartridge back into the valve body with an application of non-petroleum-based plumber’s grease.
Apply this liberally all over the device. This keeps the internal parts lubricated and working.
Step 10. Insert the new cartridge
Insert the new cartridge and valve back into the wall using your photos or drawn diagrams for reference.
Put the retainer clip back in and apply new caulking to form a tight seal.
Make sure all screws are secure.
Step 11. Turn on the water supply
Once everything is back in place and secure, turn the water supply back on.
Test your shower to see if the water temperature issue has been resolved.
When Should I Call A Professional?
If in doubt about the above process or the issue is not resolved after attempting it, contact a plumbing professional. They can evaluate the entire plumbing system to find and remedy the problem.
Consider having a plumber assess your water system yearly to catch any minor issues before they become major ones.
Conclusion
Showers often will not have cold water if the main water supply is turned off, there is an issue with the pressure balancing valve, or mineral buildup or corrosion has occurred.
If the water lines are off, it is easy to remedy this by turning them back on. Otherwise, a closer look needs to take place.
If frozen pipes are not an issue, then typically there is a problem with corrosion, mineral buildup, or a shower cartridge that is worn out. In this case, take apart the shower handle to access the valve and cartridge or clean or replace it.
Ruben has a diverse background in the home services industry, with experience running a construction company, a kitchen and bath showroom, and a moving and relocation company. This breadth of experience has provided him with a wealth of knowledge and expertise in various areas of home improvement in general and specifically in the heating and plumbing niche.