No Hot Water After Replacing Shower Cartridge [6 Easy Fixes]

You can change your shower cartridge to bring back the optimal performance of your shower. But sometimes, the decision backfires. The most common thing you can see is there’s no hot water after replacing shower cartridges. 

The reason is either you’ve installed the new cartridge incorrectly or the cartridge model isn’t compatible with the existing valve. Cartridges have model numbers written over the main body. You can read them and reach the seller to know about their compatible shower systems. Also, there are instructions with the cartridges that you should follow to install them. 

So, you’ve to reinstall the cartridge to make it work. Otherwise, you should contact the seller and get the right type for your shower. Read till the last of this article and know how you can deal with the situation when you find your replaced shower cartridge with no hot water. 

No Hot Water After Replacing Shower Cartridge [6 Easy Fixes]

At the beginning, we’ve pointed out the most common reason for no hot water pressure in the shower but plenty everywhere else, which is a faulty installation of a new shower cartridge. But we need to specify the reason so that you can understand what’s exactly going wrong in the shower system. Thus, here are the 6 possible reasons for not getting hot water after old shower cartridge removal. 

Note: You can also read how to fix Kohler Shower valve no hot water.

1. Cartridge Installed Reversed

If you’ve installed the cartridge reversed, the valve would do the opposite of your command.

When the hot water line of the cartridge isn’t connected with the hot inlet of the valve, the shower fails to pour hot water when the handle knob or bar is moved. 

Solution:

• Turn off the main water supply. 
• Put off the handle, nickel plate, and cartridge sleeve from the wall. 
• Bring out the new cartridge. Every cartridge Reverse the cartridge 180 degrees and install it again. 
• Put everything back in the right place and try the shower. This time, you’d find the shower pouring hot water. 

2. Hot Inlet Closed

If you have a single-handle shower faucet, you can see the main valve has two lines connected. The red-marked one is the hot water inlet that gives hot water to the shower system. 

When installing a new valve or cartridge, you’d surely close the keys of both inlet so that the bathroom doesn’t get wet and messy. But after mounting a new cartridge, if you’ve forgotten to turn on the hot inlet or the hot one isn’t at the same position as the cold supply key, the shower won’t give you hot water. 

Solution:

• Take off the handle, plating, and other decorating materials. 
• Twist the hot water key to turn on the line. Make sure both hot and cold inlet keys are at the same position for perfect pressure balance. 
• Put on the stuff that you removed and test the shower. 

3. Non-Return Valve Not Installed Properly

Many of us do some cleaning of the water line during the installation of any OEM shower parts to clean the water pipes for removing debris and mineral deposits. In some modern shower systems, you’d find check valves or non-return valves to block the reverse flow of water. 

If you’re not a regular DIYer to clean water lines, you can fail to reinstall the hot water pipe’s NRV properly in the right direction. That can become an obstacle to the natural water flow in the hot water line. 

Solution:

• Close the bathroom’s main supply connection first. 
• NRVs are usually located near the main pressure valve or handle valve. You can also watch the below video to get a clear concept of the valve’s location. 
• From that video, you can understand in which direction the valve mouth should be facing. Install in the right direction without twisting the Non-return valve too hard. 
• Reinstall everything to the right places and test the shower. 

4. Airlock In Shower

An airlock can happen even when you haven’t installed anything new or opened the connection lines of the shower system. When the air gets trapped in the pipes because of pressure regulators’ malfunction, water fails to pass through the air and reach the output.

During the installation of a new cartridge, some pipes related to the hot inlet might have suffered from an airlock. For that, you’re having no hot water for shower heads. 

Solution:

• Turn on the main supply valve completely with full pressure. 
• Remove the showerhead from the shower pipe. 
• Now, fully turn the handle to cold water. Let the shower pipe pour cold water for 5-10 minutes.
• Then, instantly turn the handle for hot water in full mode. Hot water might not come out at first. But after a few moments, you can find hot water is coming out and the flow rate is increasing gradually. Let the water flow for 5-10 minutes again. 
• Finally, install the showerhead and put back the main pressure level to normal, and test your shower. 

5. Stuck Balancing Spool

A few moments ago, we’ve talked about hot and cold water inlets. Each of these inlets contains a balancing spool that regulates both pressure and flow. If these spools aren’t in the same position, you’d get less hot or cold water. 

Also, a balancing spool can get stuck because of overtwisting or debris deposits. It also blocks the water line and prevents hot or cold water. 

Solution:

• Turn off the water supply and bring out the handle and covers. 
• Next, take out the hot inlet spool using a screwdriver or wrench. 
• Clean the spool properly so that there’s no deposit left. Change the spool if you see the threads are cut or damaged somehow. 
• Install the spool back in its place. Make sure it’s at the same position as the cold inlet’s balancing spool. 
• Test the shower by turning the cartridge head using a wrench to see if the shower’s now pouring hot water. 
• If everything’s okay, then put on other stuff back in the right places. 

6. Incompatible Cartridge Model

If you haven’t bought a universal cartridge, then it’s tough to make the new model work with a valve that can’t accept unfamiliar models. 

Solution:

• Take out the new cartridge from the valve as we’ve suggested in other troubleshooting above. 
• Match this cartridge’s model number with the old one. If the model number isn’t the same, then change the new one with a model similar to the old cartridge. 
• But if the cartridge mode matches, then try reinstalling properly. Otherwise, you need to contact the shower manufacturer company. 

[Note: You might’ve thrown away the old cartridge. In this case, you can search for the shower model on the internet and see which type of cartridges are compatible with your shower. Almost every manufacturer’s support page features this type of information.]

Key Notes

• Try to use Plumber’s grease to smoothen the cartridge movement. 
• Read the instruction manual with the new cartridge pack to make sure you’ve missed nothing important. 
• Empty the bathroom’s pipes before installing a new valve or cartridge. 

FAQs:

Does a shower cartridge affect water temperature?

The main shower cartridge has two basic jobs, controlling water pressure and executing the water temp on command. So, you can say the shower cartridge doesn’t affect water temperature. Instead, it lets water flow at the temperature you want. 

Why is my hot water not getting hot?

When your bathroom heater isn’t in a good shape, you won’t get the water hot enough. Or, the heater might not be getting enough power to work on optimal mode. 

Final Thoughts

Installing the new OEM parts properly, and putting back everything accordingly that you’ve brought out during installation are the two major basics for any DIYer. Well, the thing is you follow the basics well and you wouldn’t have to face problems like no hot water in the shower or sink.

However, as you’re already facing such a problem, you must troubleshoot it as we said above based on the point of error. But make sure you install it without leaving any loose ends. Feel free to reach us for more related information.