Safety valve for storage water heater: how to install

Decided to install a boiler? You can’t get by with his device: you need to provide for all the details and elements that will be needed during the installation process. From this article you will learn: why a valve is needed for a storage water heater, what function it has, how to install it.

The need to install a safety valve

This part protects the boiler from overpressure. When heated, the water expands, there is nowhere for it to go, since the tank is a closed space. A fuse comes to the rescue, which dumps the excess.

Water will look for a way out in the weak points of the body: gaskets, connections, pipes.

Imagine that the boiler is installed without any obstruction between it and the plumbing. When the indicators in the tank exceed the norm, water will flow into the system. As a result, a hot stream can pour out of the taps or from the toilet bowl.

The second important function of the valve is an obstacle to the reverse flow of water into the main. Why is it dangerous? With reduced pressure (for example, at night), the water from the tank will go to the drain. In this case, the heating element will continue its work without liquid and burn out. In the worst case, a fire may break out.

Some models have thermal protection. It turns off the heating element when the nominal temperature is exceeded. But if it does not work, damage cannot be avoided.

How the valve works

Let’s take a closer look:

  • The part consists of a large and a small cylinder. In the large one there is a damper in the form of a plate; it works under the influence of a spring. The small one is placed perpendicularly, and its damper operates in the other direction. It is also equipped with a drain pipe with a reset handle.

Need to empty the tank? No problem. Unplug the appliance and turn the knob. The contents will go down the drain.

  • The cold stream enters the system, putting pressure on the valve. The latter is opened by starting a thread.
  • As the boiler tank fills, the pressure inside increases, so the damper closes.
  • During heating, the readings in the housing become even higher. As soon as it exceeds the norm, the spring of the large cylinder is activated, the excess is drained through the drain pipe.

This is the principle of operation. Some “masters” believe that it is enough to install a check valve instead of a safety valve. This error can lead to a serious accident.

The boiling liquid pressurizes the tank, which has no outlet. If you accidentally open a tap at this time, some of the water will drain and the pressure will drop sharply. The rest of the water will boil instantly, the steam will fill the boiler, which will lead to an explosion. Read what to do if this happens.

We recommend that you follow the instructions for installing the water heater. This will help to avoid sad consequences.

Here are the main functions of the safety valve:

  • Blocks the flow of water into the sewer.
  • Regulates the pressure in the system.
  • Provides protection against water hammer.
  • Allows you to quickly merge the content if necessary.

Let’s figure out how to install the part yourself.

Do-it-yourself valve installation

First you need to choose the right model. If before that you had a water heater installed and you decided to replace it, then just take the old part to the store and buy a similar one. Valves are included with many Ariston, Electrolux, Termex models. But if this is not the case, listen to our recommendations.

  • In the photo below, there are two elements with a forced drain lever. To put it into action, just lift the lever. On the model on the left, the flag is attached with a screw – this eliminates the possibility of accidental draining. An arrow is also visible on the body, which indicates the direction of flow. The numbers indicate the pressure for which the element is designed. There are no symbols on the model on the right, so it is better not to choose this option.

It is important to select a device in accordance with the pressure for which the technique is designed. The indicators are indicated in the data sheet. Buying a valve without designations, you take a “pig in a poke”.

  • The elements of a forced reset are shown below. Pay attention to the fitting on the left – oblong. It is easier to put a hose with a clamp on it. Option on the right: the fitting is short, with an extension towards the end. It will be possible to put on the hose, but the clamp may not fit. On the left there is a cover that allows you to clean the hole from scale and blockage. On the right is the cheapest Chinese model without designations and a cover. It is better to refuse such.

These options are suitable for devices of 50-60 liters. For volumes from 200 liters, choose products as in the photo below.

They have a pressure gauge, a tap and an attractive design.

Tools and materials

To install you will need:

  • adjustable wrench;
  • fum tape;
  • tow;
  • sealed paste.

Stages of work

Be sure to unplug the heater. If water has been filled, drain. Installation is carried out on a cold pipeline to the shut-off valve.

  • Cover the thread with tow or fum tape.
  • Connect the valve to the pipe.
  • Tighten the connection firmly using an adjustable wrench.

Important! If frequent pressure drops occur in the system, a reduction gear must be installed upstream of the valve.

  • A tube is connected to the spout of the part, which leads to the sewer. It is better that it be transparent: so you can control the process.

To check the performance, it is enough to monitor the operation of the equipment. When heated, water should drip into the tube. If it doesn’t, then:

  • There was a blockage.
  • The device is jammed or is defective.

What not to do during installation:

  • Install stopcocks between the heater body and the fuse.
  • Install the fuse at a distance of 2 meters from the equipment.

So you can do the installation work yourself. Installation must be carried out when buying a storage boiler.

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