The water heater does not turn on what to do

The water heater does not heat water, but the indicator light is on

Damaged electrical wiring, defective heating element can lead to improper operation of the boiler. To find out why it doesn’t work, you need to inspect it carefully. The heater does not work for the following reasons: a lot of scale has accumulated on its surface, the thermal protection button does not turn on; the heater may not heat water due to a faulty safety valve. It is necessary to find out all the reasons why the water heater does not heat water, but the indicator light is on or does not light.

Often the reason of malfunctioning of the heating element can be a non-working electronic module. Do not try to repair it yourself. The unit may malfunction due to tripping of the emergency foggers. Because of scale deposition on the heating element, the fumes begin to turn on randomly.

Check the work of the water heater can be checked with an incandescent lamp. It must be connected to the heating element. After connecting, electric circuit should be connected to the power supply. The heating element is functioning correctly if the light is on. Another way is to use a multimeter. It is necessary to switch on the resistance measuring mode, connect to the heating element. If the circuit is closed, the indicator will show zero. If the circuit has a break, the indicator will be infinity.

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The water heater does not heat the water, but the lamp does not light up

There are such situations in which the heater does not heat water to the desired temperature, the lamp does not light. This problem may be caused by the following:

  • heating element is not working;
  • On the heating element there are a lot of deposits in the form of a layer of scum;
  • The safety valve does not work;
  • The electronic board doesn’t work.

IMPORTANT! To solve these problems you need to drain the water, disassemble the boiler. Check on it using a multimeter, a voltage indicator, a tester for correct operation. If the readings show that the elements are malfunctioning, replace them or eliminate the causes of malfunctioning.

The boiler doesn’t heat, but the light burns

This problem may be caused by various malfunctions.

The knob is in “minimum” mode, for this reason, the tank does not warm up to the desired temperature. To solve such a problem you can turn the knob clockwise. The thermostat is turned on. To get out of this situation, will help turn on the heat protection button. It is located in different places on different models. Valve is not closed. You need to put your palm on the riser. If it feels warm to the touch, but the water comes out cold, it means that the valve is not working. It has to be either rewired or bought and replaced with a new one. It takes a long time to heat up. It is not necessary to drain the water at once, it is correct to wait until it heats up.

Options for solving the problem of a defective heating element

Cleaning with one liter of water, 50 grams of citric acid. The apparatus is immersed in a solution prepared from these substances for two days. After that pull it out and descale. Replacement of the heating element on different models of boilers is the same. In order to perform it you need:

  • close the tap;
  • Clean the heater;
  • You need to de-energize the boiler for safety reasons;
  • Remove the protective cover;
  • Check if there is voltage using a special screwdriver;
  • Make a photo of the connection diagram;
  • Remove the heating element from the fasteners (if necessary put a cloth underneath);
  • Wait until the fixing place is completely dry (contacts should not have moisture);
  • look at the anode, find out if it is in order;
  • Check the rubber gasket for wear;
  • After the heating element has been replaced, reassemble all the parts.

After doing all these steps, make sure there are no leaks. To bleed the air in the boiler, and then plug the unit into the socket.

The water heater does not work: why, what to do

The situation is quite common: you have turned on the electric heater, after the usual time you open the hot tap, and the water is cold. This may (or may not) be accompanied by additional symptoms:

  • Power indicator does not light (heating, switching on the second circuit);
  • The boiler is electrocuted through the water (if it is not grounded. this is not necessarily a sign of malfunction);
  • water is dripping (pouring) from the water heater;
  • unusual sounds can be heard inside the body;
  • smell of burnt wiring around the electric water heater;


What to do if the appliance that worked yesterday does not give signs of life?

water, heater, does, turn

First of all, it is necessary to check the incoming electric circuits.

  • it sounds banal. but look whether the electricity is off in the house (after turning on the boiler);
  • check the circuit breaker on the line to which the water heater is connected;
  • In 90% of cases (especially if you have a flow-through water heater), the connection is made through a RCD: check and this circuit breaker;
  • we look at the temperature set on the thermoregulator (sometimes in a hurry the user forgets to set the desired mode);
  • Inspect the plug and socket of the storage water heater (at a high load, “burning” of the contacts is possible).

If the external causes are absent or eliminated (you turned on the machine, etc.), and the water heater still does not work, deal with the electric appliance. Of course, you can call a specialist or take the equipment to a workshop. However, this will incur additional costs.

Despite the apparent complexity of the design, the repair of the water heater with his own hands is possible, even in the absence of special equipment. You will need a set of wrenches, a good screwdriver, pliers and a multimeter, you may need a soldering iron.

If you have one, and you know how to use it, you have a much better chance to fix the boiler yourself.

Repair of such appliances though obeying the general logic, still it would be better to find the original wiring diagrams.

RV Camper Water Heaters: Tips & Troubleshooting

Let’s repair the heater by ourselves

To begin with, we establish the reason why the appliance does not work. If there is no leakage, there is no need to hurry to drain the water heater tank. Some elements can be repaired without draining the water. Especially since 80 or 100 liters is not nothing.

Checking the dryness of the casing at the bottom of the boiler. This can be done with gray toilet paper: the smallest leaks literally “show up” on it. In some models (such as an Ariston water heater), the bottom cover can trap condensate.

Then you will find leaking points only after removing the lower part of the case.

If the water heater does not leak, check the electrics

  • After removing the panel, first of all “test” the power cable with a multimeter.
  • How to check the control module? Begin with a visual inspection.

All connecting tracks on the circuit board should be uninterrupted, there are no signs of charring and thermal darkening on the parts.

For example, diagnosing the boiler “Termex” with your own hands, it is not necessary to remove the heating element. But be sure to disconnect all wires from the contacts.The electrical resistance of a tube heater in most cases is about 500 kohms (0.5 mOhm).

How to check the resistance, if there is no way to accurately set the range in kOhm (mOhm)? We set the switch of the multimeter to the measuring range that is as close as possible to the real one. Connect the probes to the heater contacts without touching them with your fingers. Otherwise, you will introduce an error in the measurement.

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There is no malfunction detected in the control unit, the wiring and the heating element are intact, but the water heater still does not heat water

Other faults can only be repaired after draining the water. There are several methods:

  • You can use a pressure relief valve, or a pre-installed auxiliary valve. If your boiler has this type of shutoff valve.
  • Some models have a third connection for the water drain. With it, it is much easier to repair the boiler with your own hands.

What else can go wrong?

If the power light is lit, but the water still does not warm up, the cause may be in the pressure sensor (not to be confused with the mechanical safety valve, which is built into the intake tube). It prevents the tank from deforming when the water is overheated if the thermostats malfunction. There is a diaphragm inside the device.

It is a movable part of the sensor, which reacts to the excess pressure. If the measuring orifice is clogged with scale, the diaphragm will not return to its original position and gives a heating lockout signal. If it is not possible to clean the hole, it must be replaced.

A defective thermostat can either over or under read. If in the first case one of the protection sensors is triggered, in the second case it simply does not heat up to the set temperature. Checking this module is difficult.

How to change the thermostat? It is located at the bottom, at the pad where the heating element is located.

Separate procedure. replacing the heating element

This is necessary when you are certain the heater has failed, or if the heater mounting flange is leaking. In any case, a revision of the internal space of the boiler does not hurt. At the same time you will be able to clean the heating element from the scale.

Of course, this situation is only possible with very calcified water. However, even normal water hardness, and ignoring maintenance, will make your heater a useless piece of iron.

As you can see from our material, water heater repair is possible even at home. However, it will be better to prevent the occurrence of breakdowns. It is enough to perform timely maintenance procedures (cleaning, diagnostics), and monitor the water quality: up to installing a filter in front of the heater.

And remember the connection of safety systems: RCD, grounding, equipotential bonding.

  • No electricity. They recommend checking the power cord for punctures or other damage, using a tester;
  • The socket is broken.
  • The safety cutoff device does not function. To check it, press the RESET button: indicator is on, it means there is power in the network. Then press TEST. When the light goes out, press RESET again. If the light bulb lights up, it means that the RCD is not broken, and you need to look for other causes of failure in the electrical system.
  • FET is broken. This often occurs due to the accumulation of scale on the mechanism, so experts advise to change the magnesium anode periodically (after about two years of operation).

The heating element doesn’t work

If the problem is not in the thermal protection, probably burnt out the heating element itself. To diagnose it, you will again have to use a tester. If the tester doesn’t beep when trying to test it, and if in the resistance measuring mode the indicator shows a gap or infinity, there is a break inside the heating element, it must be replaced. And it is much easier to do than to change the whole appliance.

For flow-through models of water heaters there is another common malfunction. the pressure sensor does not work. Its operating principle is based on the use of an elastic membrane that stretches under the pressure of water and mechanically closes the contact that delivers current to the heater. When the diaphragm is worn out, it can tear or stretch. In this case, it is advisable to replace it with a more durable, silicone.

Reasons why the boiler could break

When buying a boiler you should take into account the fact that the high cost of the device is not always a guarantee of long-term operation and lack of damage. However, if they occur, for example, the boiler does not turn on, do not worry. In most cases it can be repaired by yourself. It is important to determine the cause of the failure correctly.

Before installing the device it is necessary to study the instruction manual and the technical passport. These documents contain a detailed description of the main elements and all necessary information for its proper use. Manufacturers, as a rule, recommend regular maintenance of the device, but malfunctions of the boiler can still occur.

The main causes of malfunction of the water heater:

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  • Lack of voltage in the mains or damage to the cable;
  • Improper installation of the boiler;
  • Scale formation on the parts and corrosion of the bulb.
  • Breakage of the pressure sensor.

Important! Before beginning to dismantle the boiler it is necessary to disconnect it from the network and drain the water.

Lack of voltage in the electric network

First of all, you must check the socket by plugging in any other appliance. If it also does not work, it means that the reason is the general lack of power. Low input voltage in the network significantly impairs the operation of electrical appliances. Special attention should be paid to cable integrity.

Incorrect installation of the boiler

It is very important to install the water heater correctly. This task should be approached as responsibly as possible. Ideally, connection should be carried out by a professional. An improperly installed boiler may not function properly and can be life threatening to users.

  • The size of the wall on which the boiler will be installed. It must withstand the weight of the device filled with water. The water heater is recommended to be installed on load-bearing walls.
  • The need for thermal insulation of pipes. High insulation helps to maintain a high water temperature, which will reduce the time of heating water and reduce energy costs.
  • The presence of an expansion tank. Water leakage can occur suddenly. The presence of a storage tank will help to avoid flooding the room with water.
  • Availability of a safety valve of the water heater. In normal operation, the device heats water to the desired temperature. In the event of a breakdown, however, the water heats up to boiling point and the internal pressure rises considerably. In the absence of a valve, the pressure is not contained. Result: tank rupture with all the ensuing consequences.
  • Installation of grounding in accordance with electrical safety rules.
  • The availability of free space near the water heater for easy maintenance.

Scaling of parts and corrosion of the bulb

All internal parts of the tank are subject to scale build up. Hard water in the water supply consists of many salts that are deposited on the walls of the boiler, the heating element and coil surfaces. Over time, the heating element stops heating water at full power and consumes more electricity to heat water. Energy costs are high and water temperature is low as a result.

Malfunctions of the water heater and corrosion of the bulb. In this case the corroded tank should be thrown away. Theoretically it is possible to seal the hole inside the bulb, but this method only temporarily solves the problem.

How to prevent lime scale build up? It is for this purpose in modern devices there is a magnesium anode, which prolongs the life of the boiler. It does not play a role in heating water, but without it the device will not work more than a year on average. The anode actively prevents the formation of limescale deposits. Oxidizing magnesium ions enter the water, react and form magnesium salts. Due to their brittleness, they immediately precipitate, so that no lime scale appears on the heating element. The boiler must be cleaned annually and the used anode replaced with a new one, if necessary.

Failure of a pressure transducer

The pressure reducer or pressure sensor is a device designed to reduce inlet water pressure and protect devices from water hammer caused by momentary changes in water pressure in the system. The consequence of high pressure is a hose burst. Such a shock results in the rupture of rust-covered pipes and the rupture of plugs. The average water heater is designed for a water pressure of up to 4 atmospheres. Pressure of water more than 8 atmospheres on the inlet leads to the malfunctioning of the safety back valve through which the water begins to drop. The ruptured membrane no longer performs its protective function and should be completely replaced.

Broken outlet

It happens that the outlet, which powers the boiler, ceases to provide enough voltage or is simply not compatible with the device. this is a common cause that your water heater does not turn on. In the first case, check the working capacity of the socket by plugging in another appliance. Replace the old socket with a new one, or move the water heater to another place.

Remember that you can not connect devices to sockets that are not designed for high voltage. this can lead to a short circuit or damage to the unit. Among other things, consider the state of the home wiring, because such a powerful electric device will have on it a serious load.

The water heater does not turn on: causes

Of course, the troubleshooting of such a complex device, as a water heater, should be made by a master. It must be a qualified person, a professional of his craft, which can not only understand exactly why the boiler does not turn on and does not warm water, but also qualitatively repair the device. Still, there are some manipulations you can do yourself in order to avoid wasting money on a call to the wizard. Why can’t I turn on the water heater?? And why it does not heat the water?

So, before carrying out an inspection, the water heater must be disconnected from the power grid.

Diagram of an electric water heater.

This manipulation is extremely important in terms of safety. Also be sure to drain all the water that is there. Everyone knows the fact that electricity and water. it is definitely a killer “mixture”, and therefore it is not worth the risk, but simply drain the water and de-energize the device.

The first thing to remove is the lid of the device, under which the board, thermostats and wires are located. This is the structure of a standard water heater. In rare cases, these or other designs may be equipped with something else besides what has been listed. But that doesn’t happen very often.

So, the first cause of water heater malfunction may lie in the electricity. Ideally, the current passes through the terminals of heating elements, thanks to which, in fact, the water is heated. You can find this out with the help of a special tester. It is sold in specialized stores. Sometimes it comes with the water heater itself. With a special tester you can identify the lack of continuity in the supply wires, faulty contact between the wire and the terminal of the heating element.

It is equally important to check the integrity of the heating elements. In addition, you need to identify the presence of holes in the body of the device. You can also do this with another special tester. The water heater will never work if the coil is damaged. The same applies to the hole in the housing.

Check the electrical elements and the heating element

If all is well with the electricity supply to the appliance, but the Ariston water heater does not turn on, the tank is de-energized and all water is drained. After that you need to remove the lid of the housing. Underneath it there are wires, thermostats and boards.

Then use the tester. use it to check the power supply to the terminals of heating elements. It is quite possible that the integrity of the power supply wires is broken, or there is no contact between the wire and the terminal on the heating element. Tester is also used to test the functionality of heating elements, because they can burn out or puncture on the body.

If the coil inside the heater failed, the boiler will not turn on, as it can not heat water. With a breakdown in the case, it also will not work, since immediately after turning on the circuit breaker (RCD) will work.

Note that a burned out heater can not be repaired. Only to be replaced, and if you are in doubt about the choice of a suitable heating element, it is better to contact the professionals Repairtechnik. They will pick up a heater that corresponds to the brand, capacity and dimensions, and you do not have to dismantle a heavy tank.

When do you need a heating element replacement?

When the lamp is lit, but the water heating is very weak or absent at all, constantly occurs automatic protection when you turn on, then the reason why the water heater does not heat water, lies in the burned out heating element. Experts believe that the average life of the heating element. 4 years.

Check the efficiency of the heating element with a multimeter. If it shows infinity, there is a breakage, and if 0, there is a problem. Because of a short circuit.

To replace a burned out heater, which causes the water heater Ariston does not heat water, you must turn off the water supply and electricity, drain the tank and remove the protective cover. Some models of boilers will have to be completely dismantled. Remove and disconnect wires. The heating element is removed from the screws and a new one is screwed on, after which the integrity of the anode and the rubber safety gasket should be visually checked. You may need to replace them as well.


After assembling in the reverse order you need to check the absence of leaks and the correctness of the cold water supply. Then you need to release the air accumulated inside the tank, and only after that connect it to the network.

If you do not want to understand all the intricacies of the repair process, then contact the professionals Repair Technician. The master will come immediately after receiving the request, with all the necessary tools. You will not need to look for the right parts or understand the wiring diagrams. Diagnostics to determine the cause of the failure will be carried out quickly and accurately.

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