How Do I Replace a Shower Valve?
When your shower faucet is leaking/dripping water, you cannot achieve the desired shower water temperature, the shower handle is stuck or hard to turn, you most likely need to replace the shower valve. You may also replace an old shower valve in favor of a modern and better one.
A shower valve basically turns water to your shower on and off, and also mixes the cold and hot water. A defective valve will fail to correctly mix the cold and hot water, the number reason you may be having no hot water in your shower.
In order to replace your shower valve, you must first identify the type of shower valve you have. Apart from the brand, there are also several types of shower valve with respect to how they work and also how they are installed.
The different types of shower valves are:
1. Shower Mixing Valves
If you live in an old home and haven’t replaced the shower valves in a long time, this is what you have in your bathroom. Mixing valves will draw water from the cold and hot water lines, mix them to achieve the correct temperature then send it to the shower head.
The problem with this types of shower valves is that if for instance someone flushes the toilet or runs the washer, the cold water pressure reduces meaning you will have a sudden gush of scalding hot water in your shower head.
Also, if the hot water washer fail (they do so more than cold water washers), cold water will flow back to the hot water line, and as result you will have no hot water in your shower.
2. Pressure-Balancing Shower Valves
Pressure-balancing shower valves are what you will find in most modern homes or renovated old homes. These valves have a mechanism for balancing the pressure of the cold and hot water, for a constant flow.
This means that even if someone flushes the toilet, the pressure of the cold water will be properly balanced and you will not be scalded by hot water.
For anyone with the old mixing valves, my advice would be to upgrade to a pressure-balancing valve. I have a guide on that later in this post.
3. Thermostatic Shower Valves
Thermostatic shower valves are the modern shower valves. They adjust the temperature of the water flowing to your shower head automatically, the same way the thermostat in your water heater keeps the water at a constant temperature.
These types of shower valves have a dial that allows you to adjust the temperature of the water. You may also have anti-scald or anti-cold mechanisms which prevents scalding or cold water shocks.
4. Shower Diverter Valves
If you have a shower-tub combo, you might also have a shower diverting valve. It is usually the third valve in a three handle shower valve.
Shower diverter valves are installed alongside pressure-balancing valves. Both the cold and hot water lines have a pressure-balancing valve.
How to Replace a Shower Mixing Valve
To replace a shower mixing valve, you will first need to turn off water in your house. That might be inconvenient for some people.
If you are lucky, your shower valve might have shut off valves, so I would not advice turning off the water just yet.
Before removing the old shower mixing valve, you should first make sure that you purchased a similar replacement valve, preferably by the same manufacturer of the old one. If you have the valve ready let’s do it then.
This is how to remove and replace a shower mixing valve:
- Plug off the bathtub/shower drain. You do not want to lose anything to the drain.
- Remove the faucet handle index. At the tip of the shower faucet handle you will see a small index/cap. Pry it off with a flathead screwdriver.
- With the index off, you will see a screw that connects the handle to the valve stem. Remove it with a screwdriver. Hold the handle firmly with your hand as you turn the screw
Please note that faucet handle will differ in style depending on brand, but either way there will be a screw connecting the handle to the stem.
- Once the screw is out slide out the handle.
- Remove the trim plate. The faucet trip plate/escutcheon will be attached to the wall using one or 2 screws. Loosen them with the screwdriver and take the plate off.
- Check for water shut off valves. With the escutcheon out, you can now see the body of the valve. Check for 2 screws on either side of the valve. If you see 2 screws, those are the cold and hot water shut off valves. Turn them with a screwdriver to shut the water to the valve. If you do not see the 2 screws, you will need to turn off water in your entire house.
- After turning off the water, you will see 2 screws connecting the valve cap to the valve body. Loosen the screws with a screwdriver and take the cap off.
- Pull the valve out. With the cap out, you can now see the shower mixing valve. Grab it firmly with a pair of pliers and pull it out. You may need to wiggle it a little as you pull it out as they are usually sticky when they have not been used for a long time.
- Prepare the new valve. There are 2 O-rings that should sit at the 2 holes at the front of the valve. Stick them using plumber’s grease.
- Push in the new valve. You will notice that there a small key at the top of the valve. That key needs to align with a groove inside the body of the valve. Match it and push the valve in.
- Install the cap. The cap has 2 pieces of small O-rings and a bigger O-ring that covers the entire circumference of the valve. To help them stick, lubricate them with grease and push the cap inside the valve body.
- Align the cap with the holes on the valve. If the new valve comes with a mounting plate, install it as well and align it with the holes in the cap. Fasten it using the brass screws provided.
- Turn the water back on by turning the screws in the opposite direction.
- Mount the trim plate. Align the plate with the holes on the valve and tighten it in place with the screws as well.
- Install the handle. This will depend on whether you are installing the same old handle or a new one. With the old handle install it as it was before but if you have new one follow the schematic provided. While mounting the handle, make sure that you install it while in the off position.
And basically that is how to replace a shower mixing valve. If you would like to follow all the steps above from a video, this one here below is a really nice one.
How to Replace a Shower Mixing Valve with a Pressure-Balancing Valve
As I stated earlier, shower mixing valves are the old way of doing things. If you are tired of being scalded while taking a shower when someone flushes a toilet, you need to replace your old mixing valve with a pressure-balancing valve.
With a pressure-balancing valve, the pressure of cold and hot water flowing to your shower will be balanced, meaning you will suffer no scalds.
The only problem about this process is that it is a little harder that a simple replacement. This is because you will need to cut a piece of the wall, cut out the old valve body then solder in a new one.
If your DIY experience is not up to par with the requirements of this job I would recommend that you hire a plumber or handyman to do it.
To help you appreciate the process even more, I will leave this video here for you.
How to Replace Pressure-Balancing Shower Valve
If you have a pressure-balancing shower valve that you need to replace, the process is the same as the one outlined above. Usually this is the scenario you will have:
- Two-handle shower valve. With a two-handle shower valve, one will be dedicated to the hot water and the other will be for the cold water. Although there is nothing wrong with that kind of installation, you might want to replace it with a single-handle shower faucet.
- Three-handle shower valve. With a 3-handle shower valve, the middle handle usually works as a shower diverter valve. Instead of such an installation, you may opt for a single-handle installation with the shower diverter mounted on the bathtub spout.
Replacing such a valve will also require you to cut through the wall in order to access te old valve, cut it and then solder in the new one.
Again, this is critical job that is well illustrated using a video. To help you replace your old shower valve with a new one I will drop this video for you.