How To Descale a Heat Exchange Espresso Machine

by Whole Latte Love Updated: May 5, 2021 3 min read
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A pretty frequent question we get is “how do I descale a heat exchange espresso machine like my ECM Technika IV?” Well, we’ve got a step-by-step guide on how to descale semi-automatic espresso machines with heat-exchange boilers.

Similar to changing the oil in your car, descaling is one thing you must do on a regular basis to extend the longevity of your machine and avoid potential costly repairs in the future. How often you descale is based on machine usage and how hard your water is. If your machine is used daily with moderately hard water, we recommend descaling every 45 to 90 days.

However, this interval is subject to change if you have particularly hard water or if you’re using your machine very heavily. Take caution if your machine is severely behind in preventative descaling. For example, if it’s been 4 months of daily use without being descaled it may be best to have your machine serviced professionally. Descaling a long neglected machine can free large scale deposits which can plug up components like valves and gauges.

When descaling your machine, you’ll need three things. A blind filter, also known as a back-flush disc mounted in your portafliter, a large liquid receptacle, and a descaling agent. Descaling agents are available in powder and liquid forms. If your machine’s manual specifies a specific brand (Breville for example) we suggest you use that.

If your machine’s manual does not specify, descalers from Durgol and Urnex are a fine choice. We especially like Urnex Full Circle products which are biodegradable, phosphate free, and odorless.

Now we’ll get into the step-by-step process. To get started, turn your machine on and let it heat up to operational pressure. This descaling process is the same for most any machine with a heat-exchange boiler:

Descaling an HX Boiler, Step-By-Step

  1. Once your machine is up to temperature turn it off. Then open the hot water valve.

  2. Steam pressure forces out liquid water in the boiler.

  3. After that, operate the brew group lever to discharge water in the heat exchanger.

  4. When no more water flows, close the hot water valve and the brew group lever.

  5. Prepare the descaling solution according to the instructions. If using Urnex Dezcal or Full Circle descaler, mix the powder or liquid with 32 ounces of water. If using the powder type, be sure to mix until completely dissolved.

  6. Add the descaling solution to the machine’s water tank and turn the machine on. The pump will turn on filling the boiler with the descaling solution.

  7. After the pump stops operate the brew group lever until liquid is discharged by the group. This fills the heat exchanger with the descaling solution.

  8. Now place the portafilter with the blind filter into the brew group and lock in place. Now operate the brew group lever 3 times, leaving it in the run position for 20 seconds each time. Move the lever to the lower position after each operation. This process descales the expansion valve.

  9. Now let the descaler react in the boiler for 20 minutes. After that, release the remaining descaler by operating the brew group lever until the water tank is empty and no more liquid is dispensed.

  10. Switch off the machine, Remove the nozzle from the hot water dispenser and open the hot water valve. Steam pressure will push out any descaler left in the boiler. We took off the hot water nozzle so no scale gets trapped in it when draining the boiler.

  11. Remove the water tank, rinse and refill with fresh water. Replace the tank and turn the machine on. The boiler will refill with the fresh water.

  12. When the pump stops operate the brew group lever three times for about 20 seconds each with the blind filter still in place. This rinses the expansion valve. Be sure to move the lever to the lower position after each operation.

  13. Remove the blind filter and operate the brew group lever for about 60 seconds in order to rinse the heat exchanger.

  14. To fully rinse the boiler, repeat the following procedure 3 to 5 times.

  15. Switch the machine off and operate the hot water valve to drain the boiler. Refill the water tank and turn the machine on. Allow the machine to come up to operating pressure. Then turn the machine off and open the hot water valve to drain.

  16. Again, repeat that process 3 to 5 times to fully rinse the boiler. When done you have completed the descaling procedure.