Thermostat is an essential part of HVAC systems and cars. They help to measure the temperature and maintain it within the optimal range. Unfortunately, they are prone to malfunctioning but it’s not possible to notice the errors at the first glance until you’re aware of them.

What are the symptoms of a bad thermostat? Let’s find this out.

What is thermostat, its features and benefits

A thermostat (check it out on this site) is a regulating device that is triggered when the degree range changes and turns off / on the supply of electricity to the heating element. It is connected to the heating element with standard connectors, like a “plug with a socket”, the voltage is supplied to the thermostat through the screw terminals.

When the thermostat sensor registers the temperature below the set one, the device turns on “heating” – it supplies the mains voltage to the heating element. When the temperature reaches the preset value, the appliance turns off the “heating” mode.

When the heater is in operation (the overheating device contacts are closed), the on and off cycles of the heating element are performed and controlled by the control thermal unit and depend on the degree range selected by the user.

The benefits of thermostats are:

  • This is a simple and yet reliable construction for heating;
  • It measures the temperature of water and performs heating automatically;
  • There are different types of devices available – the spheres of application are numerous.

Types of thermostats

Today, car manufacturers equip engines with different thermostats. There are several main types of these useful structures:

  • Electronically controlled devices. Suitable for all operating modes of the power unit. Electronic devices are equipped with a special heating resistor. Known for their efficiency and accuracy. Their use can reduce the degree of fuel consumption.
  • Single valve. Reliable and durable unit. The majority of cars are equipped with a single-valve thermostat.
  • Two-valve. There are two valves in one thermostat: a main valve and a secondary valve. The main one is used to circulate antifreeze in a large circle. The second, the so-called bypass valve, performs similar actions, only in a smaller circle. Two-valve thermostats are in demand in some particular countries, for example, CIS.
  • Two-stage. The design also includes two valves: large and small. Such device is recommended to be installed in a system with high coolant pressure.

Signs of bad thermostat

Key indicators of poor device performance:

  1. The valve is seized when closed. In such a situation, the sensor is triggered, but cannot open the damper, which is why the antifreeze continues to heat up. You can find the readings on the dashboard when the overheating indicator comes on.
  2. Loosely-closed valve at the beginning of work. The fluid moves immediately in a large circle and cannot reach the temperature required for engine operation of 90 °C.
  3. Warming up of the car engine to the desired mark is too long, or gradually leads to excessive heat.
  4. The arrow that indicates the temperature of the engine drops sharply when the car picks up speed and rises at the moment it stops.
  5. The lower branch pipe becomes warm after a couple of minutes of warm-up – means that the appliance is constantly opened.
  6. The thermostat is stuck and is in a closed state when the engine itself boils, and the lower pipe continues to remain cold when the engine is warm.

How to prevent the above-mentioned issues? Choose reliable devices from well-established manufacturers. Partzstop offers the whole gamut of quality thermostats from the leading producers. Make sure to check our store.