Below are the instructions I use to descale my Lelit Elizabeth PL92T espresso machine.
Before you begin
- I am using Durgol Special Descaler liquid (125ml), diluted with 500ml of water
- The coffee boiler is 300ml in size
- The steam / hot water boiler is 600ml in size
- The complete procedure will take more than 1 hour
- Have 4-5L of fresh water ready for flushing
Knowing the boiler sizes helps determine how much descaling solution is needed to fill the boilers and run through them at least 3 times.
Product I use
I am using the Durgol Special Descaler solution. Lelit recommends Jura, which is difficult to find from where I am. Use of store-bought descaling solution is recommended. Diluted vinegar may stick to the boiler and add unpleasant taste to your coffee.
Prepare the machine
I will be using the 1cup program for the descaling process. For that, turn off the program timers. I don’t want the machine to overheat. Plus it should not require very hot water for the descaling process. That said, make the following adjustments on Elizabeth:
- Turn off the 1cup timer
- Turn off the 1cup pre-infusion timer
- Reduce the coffee brewing temperature to 80C (the lowest)
- Reduce the steam temperature to 115C (the lowest)
Prepare the descaling liquid
In a measuring cup, add 500ml of water and 125ml of Durgol descaling solution. If you do not mind using more descaling solution, mix 250ml of Durgol into 1000ml of water. Pour the diluted solution into the water tank.
Start the cleaning process
First, we want both boilers to be filled with the descaling solution. Start by dispensing 500ml of hot water. You will notice at the end, Elizabeth will prompt you to add water. Pour the solution back into the water tank and let the pump draw it back into the boiler.
Next, dispense 300ml of water using the 1cup coffee button. Pour the solution back into the water tank, wait 1 minute and dispense another 300ml of water using the 1cup button.
At this point, both boilers should be filled with the descaling solution. Give it a few minutes to work its magic.
Next, repeat the dispensing and refilling process several times. The objective is to have at least 600ml x 3 of the solution runs through the steam boiler. 300ml x 3 of the solution through the coffee boiler. Pause for 1-2 minutes between each run to prevent overheating the boilers.
Clean the steam wand and the solenoid valve
The only elements remaining to be cleaned are the steam wand and the solenoid valve. To clean the steam wand, dispense 200ml of hot water into a container, submerge the steam wand into the water and turn on the steam for 1-2 minutes. The same process as frothing milk. This way, the steam will stay in the water, instead of being blown out everywhere. The descaling steam does not smell very pleasant. I try not to breath in too much of it. Repeat the process 3 times.
To clean the solenoid valve, install the blind basket into the portafilter. Lock it in to the group head. Press and hold the 1cup then press the hot water button. It will start the back flushing cycles. The descaling solution will now run through the solenoid valve into the drip tray. Repeat the back flushing cycle 3 times.
Flush out the descaling solution
Empty the water tank, fill in fresh water. Follow steps similar to the above and run the fresh water through the boilers at least 3 times, or until the water coming out becomes clear and odorless. Note that this time, only refill the water tank with fresh water. You don’t want any descaling solution going back into the machine.
During the cleaning process, some of the descaling solution may be splashed onto the body of the machine. Wipe it off with a wet cloth immediately. Do not let the descaling solution stay on the metal part of the machine. It will leave a stain and i have not figured out a way to remove the stain.