If you have problems with a TMV, then you sometimes see outward signs that all isn’t well. For example, water might seep out of parts of the valve; you may even see some water on the floor under it. This might indicate a faulty seal or a corrosion problem.

I should have gotten a large adjustable wrench for the top piece of the regulator, but instead used channel lock plyers.

In some cases, a faulty TMV can also affect your cold tap. Here, you might find that this tap runs warm or hot rather than cold.

I thought I was going to have to use one pipe wrench to hold the main body of the regulator while I used the other pipe wrench to turn the top piece of the regulator, but the pipes going into and out of the regulator seamed sturdy enough.

However, excess heat isn’t the only sign of trouble here. Sometimes, a failing TMV makes the water too cold. Or, water may not run at the right temperature consistently. It may fluctuate between being hot and cold.

A thermostatic mixing valve (TMV) bridges the hot water in your system and the water that comes out of taps or showers. It keeps your hot water system safe in a couple of ways, and can keep you safe, making it a crucial part of your home plumbing that your local plumber should always check.

If you have a TMV in your shower, then a faulty valve can make the shower drip even when it is off. Here, the valve may not be in the right position so it doesn’t shut water off effectively. Or, you may have a problem with the valve’s seals or cartridge.

For example, your water might start to run sluggishly and slowly all the time. You might struggle to get the tap to give out more than a trickle of water. Or, your water might switch between working normally and running at a reduced pressure or flow.

Sometimes, the first sign of a TMV problem is a change in the way your water comes out of a tap. Typically, you see a reduction in flow or pressure here.

I used a water pressure gauge to help trouble shoot the main problem and to make sure I adjusted the rebuilt regulator to the right pressure.

The top o-ring, of the basket, needs to be lubricated before being inserted. The rebuild kit came with a small packet of silicone lube. After inserting the basket there is a washer that goes on top of the basket. Then the spring, spring top piece, and regulator top piece screw on top. This is easier if you have the pressure screw turned almost all the way out so there is hardly any pressure on the spring.

Turn the water back on by opening the main water valve. Check the water pressure with the gauge. Slowly tighten the water pressure regulator adjustment screw clockwise until you have your desired water pressure. I found out the correct pressure should be between 70 and 85 psi. It may be different for you depending on your house and where you live.

If a TMV valve stops working correctly, then you may notice that your hot water suddenly starts to run hotter than it should. If the valve can’t regulate temperature correctly, it might not be able to cool hot water down enough to make it safe.

First, it allows your system to store water at a high enough temperature to keep bacteria at bay. However, it also regulates the temperature of the water that you use.

Again, these problems can have various causes. Sometimes, water can’t run through a TMV freely because parts of its valves are gummed up with debris or scale. Older valves might also suffer from corrosion which blocks them up. Or, a valve might not have been fitted correctly in the first place.

I turned on the main water to help flush out the main body of the regulator. To keep from making a mess, I used a piece of plastic to direct the water into a bucket. After rinsing out the regulator, I used an old t-shirt to clean out the inside of the regulator.

The first sign that something was wrong was there seamed to be a loss of water pressure in my house. Taking a shower, seamed like there was hardly any pressure. I hooked up the water pressure gauge and found that the pressure was fine. Running the water, into a bucket, made it easy to see that the flow of water was slower than it should be. I asked a neighbor if he was experiencing any loss in pressure or flow, since we are on the same water supply. He said that his water pressure and flow was fine. That removed the possibility that the problem may have been the water supply pressure or flow. This led me to believe that there was something wrong with my water pressure regulator.

Once reaching the desired pressure, I let the water run for a bit and then double checked the pressure. I also checked to make sure there were no water leaks at the pressure regulator valve.

When you turn on a tap or shower that connects to a TMV set-up, then the valve controls the release of hot water. Typically, it mixes hot and cold water together to reach a set temperature as dictated by its thermostat setting set by a plumber with a TMV licence. So, your water should never run so hot that it could scald or burnWhen all is well, the TMV works seamlessly. However, it might develop problems that prevent it from working as it should. What are the signs that your valve has a fault?

If you have concerns about a TMV, then you need expert help. Don’t try to fix these valves if you don’t know what you’re doing. They are too important a safety job to mess up.

Rebuilding a water pressure regulator valve is easier than replacing one. I will show you how I rebuilt my water pressure regulator.

Changes in water temperature have various causes. For example, the valve may be blocked or may have moved out of position. The thermostatic element might have stopped working or might have a problematic O-ring. Or, you might have a problem with water pressure or flow through the valve.

Before taking apart plumbing, it is important to shut off the main water supply and relieve the pressure in the pipes. My main shut off valve is right beside the water pressure regulator. After closing the main water valve, I relieved the pressure, in the pipes, by opening a water valve and letting the water run until the pressure was relieved.

I used the 9/16" wrench to loosen the jam nut and then remove the pressure adjustment screw. I started loosening the top piece of the regulator by using a pipe wrench. I found that it was easier to use channel lock plyers. Carefully remove the top piece because there is a spring, a washer, and metal piece that will fall out. I found that the main spring was broken and this was probably the main reason that my water flow had decreased. I then used the channel lock plyers to remove the basket from the regulator main body.

For a quick diagnosis and fix, contact plumber Wahroonga Andrew Vanny Plumbing . We can check your TMV over and repair or replace it for you.