What is a good capillary thermostat
There are some classifications of thermostats, according to which a water heater can be divided into several types. Electromechanical-electronic, which affects the way of control. Programmable or simple, which will affect how the temperature is set. Mortise or overhead, which affects the method of installation.
Basically, the thermal switch is:
The peculiarity of the rod model is that it is the oldest device. It looks like a small tube, which is 35 cm long and 1 cm wide. When it is exposed to high temperature, the tube expands in size, and the switch is pressed. That's how this system works.
The principle of operation of the capillary thermostat is slightly improved, since it appeared after the rod one. The type of thermostat is a tube with cylinders located inside it. They contain a liquid with a density different from water. When heated, there is an increase in the volume of liquid, the cylinder begins to put pressure on the membrane and on the shutdown device. In terms of accuracy, this method has a discrepancy of 3 ᵒС.
An electronic type thermal sensor is the most common model and it is the most accurate among the rest. The perfection of the model lies in the fact that the temperature sensor has a direct interaction with the protection relay, due to which an emergency automatic power off is carried out if there is no liquid in the tank.
Types of thermostats
Water heaters can be equipped with different thermostats. The main types are rod, capillary, electronic.
Rod thermostat
for a water heater - this is today the most popular type. It is a small tube in diameter that functions according to the laws of physics. When heated, the tube expands linearly and presses on the switch, and when cooled, it contracts and turns on the heating element.
It has the disadvantage of inaccurate work, since its location is close to the water supply.
The storage boiler is designed so that when hot water leaves, cold water immediately enters the tank so that the water level is always the same. Since the rod thermostat is located near the cold water supply, it has critically little time left to expand to the desired size. Cold liquid quickly cools it, and the boiler functions almost non-stop during its use.
Rod thermostat for water heater
Capillary protective
the thermostat for the water heater is a more modern solution. It consists of the same tube of small diameter, in which there is a capsule with a contrast liquid. Such a thermostat changes its volume from the temperature in the heater tank. At a certain heating, water presses on the membrane
, which is associated with electrical contacts.
Capillary thermostat for water heater
Electronic thermostat
for a water heater is also considered a modern option. For better functioning, it interacts with a protective relay
. This makes it possible to cut off the power supply in case the water heater tank is empty.
Electronic water heater thermostat Ariston
Of course, there are other classifications of thermostats. If viewed from the side of the main control element, then electromechanical and electronic devices can be distinguished. If we take as a basis the method of indicating the temperature, then there are simple and programmable. Surface and mortise thermostats
distinguished based on the type of installation.
Frequent malfunctions of the thermostat for heating elements
Any appliance in the house can break down, even if it is a high quality and super expensive boiler. The cause of the breakdown can be absolutely any factor, both external and internal.
There are a number of major breakdowns that you should definitely pay attention to:
- The copper capillary tube wears out.
- The three-pin thermostat and heater interact poorly with each other.
- An error has occurred in the regulation of the heating element.
- A scum has formed.
- There was a breakdown due to power surges.
It is worth noting that if there are no skills and knowledge regarding working with a thermostat, then it is best to replace and repair this part in the boiler by a specialist so that there is no uncertainty about the correctness of the actions performed, and the device regularly performs its direct duties.
How to check the thermostat
The failure of the thermostat is a common cause of failure of even the highest quality boilers. You can notice the problems yourself, without outside specialized help.
The most common problems associated with thermostats can be the following:
- the capillary tube made of copper has worn out;
- failure in the settings of the heating element;
- the appearance of a raid;
- malfunctions due to voltage drops;
- poor matching of heater and thermostat contacts.
How to check the water heater thermostat or how to "ring" the thermostat on the water heater:
- First, find out if the thermostat is working. To do this, remove it and switch to resistance measurement mode.
- In the next step, set the maximum temperature value and measure the resistance at the output and input contacts of the device. The design of the thermostat is most likely not working if the device does not “respond” in any way.
- If, nevertheless, the design is working and responded, then you need to turn the regulator knob to the smallest indicator and reconnect the tester probes to the contacts.
- At the end, use a lighter to heat the thermostat tube. If the system is working, then the relay should respond, which opens the circuit, and the resistance indicator will jump.
