How to unlock a thermostatic mixer tap?

Do you want to know how to unblock a thermostatic mixer tap ? Your thermostatic faucet has a blocking problem and you don’t know how to solve it? 

This article is made for you!

Today, limescale and other dirt increasingly accumulate in our pipes and sometimes block them, and it is sometimes very difficult to remove them.

There are certain things to respect to unblock a thermostatic mixer tap.

We will therefore see:   

• How a thermostatic mixer works 
• The causes of thermostatic valve blockage
• 5 steps to follow to unlock the mixer 
• Use a penetrating oil to unlock the valve 

Let's go, here we go! 

How a thermostatic mixer works

The thermostatic mixer, also called thermostatic valve, consists of 2 elements:  

• Thermostatic head, which allows adjusting the temperature emitted by the radiator. It is a graduated handle usually from 0 to 5. Depending on the room temperature, the head contracts or expands the system.
  
  
• Body, which is often made of chrome-plated brass, connecting the radiator to the thermostatic head. It mainly regulates the flow and circulation of water in the radiator. 

The thermostatic mixer is placed on any heating system (oil, wood, gas, heat pump…), whether on radiators or towel warmers. With precise regulation, it serves as a heat supplement to a central heating system, like a room thermostat.

It allows for significant energy savings. 

There are 2 types of thermostatic valves on the market:  

1. Mechanical thermostatic valves : the most common 
2. Electronic thermostatic valves : better and programmable, for some, via their smartphone. 

Today, more and more brands are turning to electronic thermostatic valves because they offer better features and allow the radiator to be programmed remotely. 

Why does the thermostatic mixer get stuck? 

The main reason for the blockage of the thermostatic valve is a long period of disuse without fully opening the valve. 

A limescale/mud deposit forms at the flap because the water no longer circulates. The piston will therefore remain pressed in, and this will block the hot water supply. 

In some cases, when the piston remains in the open position in the cartridge, it oxidizes and seizes, causing overheating.

→ So you need to find solutions to unlock the thermostatic valve. 

Unlock the thermostatic mixer

There are different steps to follow for unlock a thermostatic mixer. 

1/ Prepare the unlocking 

First of all, you must prepare the unlocking of your thermostatic mixer. For this, you need to avoid possible flooding. 

So you need to shut off the hot and cold water supplies. Then you will need to open the handles, to drain the remaining water from the mixer. 

2/ Locate the temperature adjustment handle 

You need to locate where the temperature adjustment handle, the unscrew with a screwdriver to be able to remove the temperature setting. 

3/ Disassemble the thermostatic head 

You will then need to disassemble the thermostatic head. For this, you will need to unscrew, with a hex key, the screw that serves as a lock. 

4/ Clean all the parts

Now you need to clean all the parts. 

For half a day, you will need to let the mixer head soak in white vinegar, in order to remove the limescale. 

As for the seals and some O-rings, it would be necessary to to grease with silicone grease. 

5/ Reassemble all the parts of your thermostatic mixer 

 Now you need to reassemble all the parts of the thermostatic faucet.

To do this, attach the mixer head with its screw using the hex key. Then, also put back the temperature handle, then the trim and the screw cover.

You can then adjust the temperature of your radiator (not exceeding 38°C) and turn on the water.

→ There you go, your mixer is now unblocked! 

Unblock the mixer with penetrating oil 

You can also unblock the mixer with a professional penetrating oil. This is actually an easier and faster solution to implement.

For this, you need to get a professional penetrating oil, whether it is WD-40 or another brand.

Then you need to follow these simple steps:  

1. With its extension nozzle, apply the penetrating oil to the seized area.
2. To avoid stains, clean the excess dripping penetrating oil.
3. After letting it act for a few minutes, turn the mixer handle. 

 And there you go, the mixer should now work perfectly.  

Here is how to unblock a thermostatic mixer

That's it, we have reached the end of this article!

You now know the best techniques to unblock your thermostatic mixer.

You have learned that there are two main methods to unblock a thermostatic mixer: by dismantling and cleaning everything, or by using penetrating oils.

→ But first, you have to have chosen the right mixer at home!

At Le Mitigeur.com , we are mixer experts and we guide you in choosing your faucets, whether for your kitchen, bathroom, shower, or bathtub.