Cleaning and Flushing

Thermal fluid for cleaning and flushing

The key to operating a cost effective and productive heat transfer system is maintaining a clean and efficient system.

Our dual action fluid will flush and clean the system in one process, leaving it ready to accept a new charge of thermal oil. Globaltherm C1 system cleaner is a unique product specially formulated to remove harsh contaminants in heat transfer systems.

Traditionally you required two separate products for this process which led to downtime lasting twice as long. Firstly you use a cleaner that is usually detergent based and is left in a system for a period of several weeks. The second process and product is a flushing oil to flush out the dirt removed by the cleaner.

Globaltherm C1 is both flushing and cleaning in one and reduces down time and cost whilst working as well or better than other product currently available.

Globaltherm C1 is recommended for cleaning and flushing heat transfer systems that use heat transfer fluids in a temperature range from -90°C up to a maximum bulk temperature of 600°C.

Over its lifetime, a heat transfer fluid degrades by either the process of thermal cracking or oxidation. During this process a fluid may become fouled with debris or harmful contaminants, such as old or oxidised residual fluids, carbon deposits on system internals, loose debris, possibly water and volatile light ends.

These contaminants can reduce thermal efficiency of the system, reduce the life of the thermal fluid and lead to the formation of hot spots on heater coils. These hot spots can result in coil failure and fire. When a fluid needs replacing, be it a new fill or old degraded fluid, engineers must drain, flush and clean the system. This will ensure that the new fluid works efficiently as soon as it enters the system, maximising the fluid life and system performance.

Circulating debris in any system, at any stage of its lifecycle is concerning as it can erode the pipework, accelerate the oxidation of the fluid and decrease the thermal efficiency of the heat transfer fluid.

Debris will also act like a grinding paste on pump seals and impellers that will eventually lead to leaks. As soon as there is a leak you are in breach of explosive atmosphere (ATEX) legislation and you must take action because leaks increase the risk of fire.

These contaminants may remain when draining the system, which can reduce the efficiency of the system and compromise the new fluid when it is introduced to the system. Typically, up to 25 per cent of a systems’ fluid volume can remain after draining down due to the physical attributes of some parts of the system such as horizontal heater coils and dead legs in pipes.

A clean system will help to maintain a safer environment and optimise performance of the new fluid. Improving efficiency will lower maintenance and operating costs and reduce downtime over time.

If the heat transfer system and internal fluid cannot maintain the required operating temperature of the process, the fluid may have degraded and may need replacing. Engineers might notice this if they are frequently turning up the temperature, but the flow rates have dropped off.

You should always take a representative sample of the fluid to find out the current condition. Thermal fluid sample data may show high TAN / acidity (oxidation) and carbon residue data. The test results may also indicate likely levels of internal system fouling along with viscosity and Particulate Quantity results.

Once the contaminated fluid is removed, you should refill the system with the cleaning fluid. You should circulate the fluid in the system at 108-122 degrees Celsius (225-250 degrees Fahrenheit).

The detergent additives are activated at this temperature and the cleaning fluid mixes with suspended loose particles and also removes any soft or intermediate insoluble carbon from the inside of the system. These particles will leave the system when you drain the cleaning fluid.

Depending on the condition of the cleaning fluid as it leaves the system, you can refill the system with more cleaning fluid or introduce the new heat transfer fluid. This is determined by an analysis of the levels of carbon and particles in the heat transfer fluid.

New systems are particularly at risk of contamination because of environmental exposure during construction. This exposure provides contaminants, such as water, soil, welding slag and finely divided ferrous material with an opportunity to get into the system and accelerate the thermal degradation process.

Contaminants can also damage other parts of the system, including pumps and seals, so it’s essential that contaminants are removed before the virgin heat transfer fluid is added and the system goes live.

All systems should be flushed and cleaned before fresh heat transfer fluid is introduced. This is extremely important as any welding slag, ferrous material or yellow metals which have not been removed during manufacture could effectively catalyse the oxidation of the heat transfer fluid and in turn, accelerate the ageing of the fluid. Water could also be present in the system after building and will contaminate the new fluid if not removed before the new fill is introduced.

Our heat transfer system drain, flush and refill service can help you return your heat transfer system to maximum efficiency. Our engineers will help to thoroughly drain the system, safely remove the condemned fluid and flush out any carbon deposits.

We can also help with waste removal and disposal of condemned fluid in accordance with legislation and help you implement a preventative maintenance programme to extend the lifespan of your new fluid.

We provide a condition based thermal fluid lifecycle maintenance programme, Thermocare, where our experts will work with you to improve accuracy when monitoring fluid condition, organise maintenance schedules and train staff at the facility.

Have you got more questions about cleaning and flushing heat transfer fluids?

Need engineering support to drain, clean and flush your heat transfer system?

Give us a call for more personalised advice on +44 (0)1785 760 555


  • Maintain a safer system environment
  • Flush and clean a system with Globaltherm C1 to maximise performance and service life of new fluid
  • Lower maintenance and operating costs
  • Reduce downtime

The dual action power of Globaltherm® C1 flushing and cleaning fluid works to rid your heat transfer system of potentially harmful contaminants such as old/oxidised residual fluids, carbon deposits, loose debris, water and volatile light ends.

Need help cleaning your system? Find out more about our drain, flush and refill services.

How Globaltherm® C1 Works

Globaltherm® C1 is specially formulated to remove harsh by-products of synthetic and mineral based fluids. It effectively displaces and flushes out waste, leaving behind a clean and safe operating system, ready to accept a new charge of heat transfer fluid.

Starting with a clean system helps to:

Use it prior to recharging a system to ensure best performance and optimum efficiency. We also recommend cleaning and flushing brand new systems before the preliminary fill to purge the pipes of any residual metals, minerals or lacquers that have settled post construction.

  • Globaltherm® C1 is compatible  with most heat transfer fluids
  • We recommend Globaltherm®C1 to dissolve sludge and clean and flush your system with no loss of production time and output
  • Globaltherm® C1 restores system performance

Globaltherm® C1 is both a cleaning and flushing heat transfer fluid product

Product 208 Litre barrel Bulk 25 Litre 1050 Litre IBC
Globaltherm® C1 Tick | Global Heat Transfer HTF Tick | Global Heat Transfer HTF Tick | Global Heat Transfer HTF Tick | Global Heat Transfer HTF