Errors when using storage water heaters

A storage water heater, also known as a boiler, is a useful and sometimes irreplaceable device. However, mistakes made during installation and use can greatly reduce the life of the boiler, or even make it dangerous to health and life.

1. Use a boiler without an RCD or with faulty protection

The water heater in the boiler is very susceptible to corrosion: damage to the heating element is the most frequent breakdown in these types of devices. In this case, the operating voltage from the heating element (230 V) goes directly into the water with which you wash. Touching the water jet (or faucet body) will give you an electric shock, as if touching a live wire. Therefore, all modern electric boilers are equipped with a residual current device (plastic box immediately after the outlet).

On some models, the RCD is not fixed on the wire, but hidden inside the case. Be sure to read the instructions before using the boiler. If your model does not have an RCD, it should be installed immediately by purchasing it separately . True, RCDs sold in electrician stores are usually placed in a shield – not everyone can cope with their installation, you may have to invite an electrician.

But as a result, not only the boiler will be protected, but all electrical appliances in the bathroom, which is very good: an electrician in a bathroom is much more dangerous than in “dry” rooms.

If there is an RCD, it should be checked periodically – for this there is a “test” button on the device case. When pressed, the boiler must be switched off immediately. If the boiler does not turn off when the button is pressed or turns off with a delay, the RCD is faulty. It is recommended that such a check be carried out at least once every three months.

2. Do not ground the boiler.

If the boiler is grounded, the protection will turn it off immediately if the integrity of the heating element is violated. But in the absence of grounding, the RCD will only work when a voltage leak occurs – for example, when you touch the jet with your hand (and get an electric shock). A high-quality and serviceable RCD will turn off the current faster than it will kill you, but you are unlikely to want to check the serviceability of your RCD in this way.

See what the outlet looks like where you connect the boiler. Are there metal contacts on the top and bottom? Not? This means that there is no grounding either.

However, if there are contacts, this does not mean that they are grounded. Taking advantage of the fact that it is not so easy for an ordinary person to check it, developers often “do a hack” and simply do not make a ground loop in new houses. If in doubt, invite an electrician and ask him or her to check that the outlets are grounded.

3. Do not monitor the pressure in the boiler.

The water heater tank also fails quite often. Corrosion or overpressure may be the cause of its leakage. Most often, in this case, a leak simply forms in it, but with excessive pressure, it can burst and even explode.

Pay attention to the maximum boiler pressure – for many models it is 6 bar. At the same time, in urban networks, the pressure can reach up to 7 bar (and for a short time due to water hammer – up to 10). You can protect against this by using a pressure reducer at the boiler inlet – it will maintain the pressure at an acceptable level and prevent water hammer from damaging the boiler. Also, a safety valve , usually supplied with the boiler, protects against overpressure .

If the pressure in the boiler rises above the allowable value, the valve will open, bleeding off excess water. Therefore, you should not worry if water occasionally drips from the valve outlet – this is its normal operation. But if the water flows from there in a trickle, then it is better to stop operating the boiler – this indicates either a valve malfunction or a high pressure in the tank.

However, excess pressure can also form due to a breakdown of the thermostat of the boiler itself. Then the heating element does not turn off when the temperature reaches 100 ° C and the water boils. At the same time, the pressure rises so quickly that the safety valve does not have time to release it and the boiler explodes.

To avoid this, you should choose reliable equipment from trusted manufacturers, well, or at least not place the boiler where people are often and for a long time – above the toilet, above the bathroom, etc.

4. Work “dry”

The boiler must be plugged in only when filling. If you turn it on with an empty tank, this can lead to a quick failure of the heating element. Some models have dry start protection, but not all.

Without water, the boiler is sometimes turned on when the device is first started, but much more often this mistake is made when the boiler is turned on in an apartment after a long break. The fact is that it is not recommended to keep water in the boiler for a long time, therefore, when there is hot water in the tap, it is correct to keep the boiler empty. The main thing here is not to forget to pre-fill it when the hot water is turned off again. Before turning on the boiler, make sure that cold water flows into it, then open the “hot” tap and wait for water to flow from it (this means that the boiler is full to the top).

5. Lack of safety / check valve

The need for a safety valve has already been mentioned above. But this valve protects not only from overpressure, but also from dry running when cold water is turned off.

The device of the boiler is such that when the water supply is turned off, all its contents will flow out by gravity through the cold water pipe, if a check valve is not installed there. The valve supplied with the boiler is usually both reverse and safety. If it is not included in the kit, then it must be purchased separately and installed at the cold water inlet.

6. Do not take into account the water hardness

Hard water is one of the main reasons for the failure of the heating element of the boiler. In hard water, limescale deposits on the heating element.

Scale has low thermal conductivity, so the heating element begins to heat the water more slowly and – which is much worse – unnecessarily heat up itself. This leads to a quick burnout of the heating element housing. There are several ways to reduce scale formation.

  • Firstly, periodic cleaning of the heating element from scale. It can be cleaned with acetic acid and should be done once a year. On soft water, this can be done less often – once every 2-3 years, and on very hard water, on the contrary, more often – 2-3 times a year.
  • In addition, timely replacement of the magnesium anode is required. The magnesium anode is a metal rod with a magnesium surface, usually fixed next to the heating element. It does not completely prevent the formation of scale, but it reduces the rate of scale formation and makes it friable. On average, it should be changed every 1-2 years, more often on hard water.
  • Reduce the hot water temperature. The higher the temperature, the more scale builds up. Therefore, it is better to set the temperature lower on hard water. True, this will reduce the volume of available warm water, which will have to be compensated for by the large volume of the tank. .
  • Use a dry heating element . In very hard water, this is perhaps the only way to operate the boiler without unnecessary worries. Dry heating element does not come into direct contact with water, but heats it through an air layer. Scale in a boiler with a dry heating element will still form, but this does not threaten a quick burnout.

7. Dilute bacteria in the tank

Warm water is an ideal breeding ground for bacteria and other microorganisms. It is clear that there is nothing good about it.

Microorganisms can get into the tank together with cold water (for example, from a well), when replacing the anode or cleaning the heating element. Bacteria will multiply especially quickly if the water flow in the tank is small and the temperature is below 60-70. Therefore, firstly, if the boiler is not in use, the water must be drained from it. You can use the safety valve for this (if it has a flag for dumping water). Or you will have to remove the non-return valve – otherwise, the water from the tank will not be drained.

And, secondly, set the temperature above 70 (yes, this is contrary to the advice in the previous paragraph).

8. Do not replace the magnesium anode in a timely manner.

Even if your water is very soft, the anode is still needed – since it not only reduces the formation of scale, but also binds the oxygen dissolved in the water, protecting the tank from corrosion. But it also wears out. When the anode is worn out, the tank will work much less, which is why many manufacturers stipulate the termination of the warranty in case of untimely replacement of the magnesium anode.