It’s one of the smallest parts on the vehicle –but the failure of the “low tech” thermostat can bring even the most modern vehicle to a halt due to over‐heating of the engine.

The thermostat, which is in the coolant circuit between the engine and the radiator, acts as a temperature controlled valve. If the closed valve fails, so does the cooling system,
resulting in an overheated engine. However, most thermostats are inexpensive and easy to replace.

The automotive thermostat was first developed in 1928, and it improved engine reliability, durability and performance output. The principle of temperature‐controlled engine
coolant has been a resilient design feature as today’s engines have developed into the smaller, more powerful units that we are used to ‐ and as demand for improved fuel
consumption and lower emissions has grown, so the development of thermostats has kept pace. Vernet currently offer two main thermostat types:

Conventional Wax Thermostats
Mapped/Piloted Thermostats

Advantages of conventional wax thermostats:
Proven product
Minimal storage space required
High volume production
Pre‐defined opening temperature
Low cost

This time‐honoured and proven design has a special wax element at the heart of a pressureresistant housing. Once the engine approaches operating temperature, the wax melts,
expanding rapidly and causing a pin in the thermostat to function as a piston. The pin acts on a plate to open the thermostat and redirect coolant flow to the radiator to keep the engine at optimum operating temperature: should the coolant drop sufficiently in temperature, the plate drops back into position closing the cooling circuit.

The average temperature variance in a working thermostat is between 12ºC – 15ºC. Thermostats can be designed to operate at different temperatures, ranging anywhere
between 0ºC – 120ºC.

Advantages of Mapped/Piloted Thermostats:
Improved operating range through variable opening temperature
Quick response time through optional current feed
Advanced engine management for reduced emissions and improved fuel consumption
Compatibility to conventional Thermostats

Modern engines have cooling requirements that conventional wax thermostats won’t manage and this has resulted in the development of the Mapped/Piloted thermostat, where
a combination of the traditional wax element is augmented by electrical heating. This also facilitates a wider variance in the operational range of the thermostat. The addition of
electrical heating is usually trigged by engine load; these ‘load‐triggered’ calibrations are stored in the engine ECU. For example, if the engine is operating between 100ºC ‐110ºC
under partial load, this would return improved consumption figures of between 1% and 2%. Conversely, running the engine at 80ºC under full load would return improved torque figures of approximately 2% ‐ 3%.

Calorstat by Vernet, the world’s premier thermostat manufacturer, has 1200 references in their latest range and are able to offer unparalleled coverage from a single source. As the preferred OE supplier for most vehicle manufacturers, you can rest assured that what you offer your customers is the genuine part. Every Calorstat thermostat comes with a gasket if one is required. The UK thermostat aftermarket offers real potential for businesses. With a car parc of approximately 32 million vehicles and a replacement rate of 10% per year, more than three million vehicles require a thermostat change annually. With 60% of these being repaired in the aftermarket, that’s 1.8 million thermostats sold in the UK, every year. For any motor factor or garage not currently in this market, this represents a massive opportunity, by anyone’s standards.

FAI Automotive is proud to offer this premier brand and is able to offer cross‐references to most competitors, so you can switch over with a minimum of fuss.

Contact FAI today for more information.
Michael Dieckmann +44 (0) 8704 391833 michael.dieckmann@fai.co.uk

 

 

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