- Thanh bác, em đã tháo cái đồng hồ Áp suất Boiler ra, nó bị can xi đóng gần kín cái lỗ đầu nối với boiler, sau khi ngâm dung dịch tẩy can xi + thông bằng cọng kẽm 0,5mm thì đồng hồ đã chuẩn , Kết hợp chỉnh trên công tắc Sirai trong máy thì đưa về đúng chuẩn 1-1,2 bar của Boiler.
- Phát sinh vấn đề là cái đồng hồ đo áp suất máy bơ ko hiểu sao khi chiết xuất cà phê cái kím nó vẩy lia lịa tại áp suất 9bar ? Các cụ cho ý kiến để em chỉnh tiếp .
Vậy bác tiếp tục tẩy cặn can-xi toàn bộ máy., Mua axit citric (axit chanh) dạng bột, pha dung dịch tẩy: 2 thìa xúp/1 lít nuớc., Máy của bác boiler lớn, chắc cần vài lít dung dịch.,
Bác làm theo cách như sau (Em luời dịch, bác chịu khó đọc hơi dài chút):
"1/ Descale the HX like you descale a home machine:
- ground the autofill wand (see above)
- fill the tank with the descale solution.
- flush the group with four ounces worth, wait 10 minutes, and repeat.
-repeat this 4 to 6 times.
- refill the tank with water
- restore the autofill
- flush the group till the taste is gone (start with 1 quart before tasting). If anyone has one with a big honking HX like the Cimbali's, please jump in with revised quantities.
2/ Descaling the boiler is more of a pita:
- The machine should be at operating temperature.
- Turn the machine Off, and run as much water out of the hot water tap as you can. Tilting the machine towards the side the pipe attached to the boiler helps.
- Fill your tank with descaling solution.
- Turn the machine on, and let the autofill fill the boiler to the normal level with descaling solution.
- Wait for the machine to reach operating temperature.
- Disconnect the autofill (see above) and let the boiler overfill. Open the steam valve slightly as this is happening. When the solution starts squirting out of the steam arm (into the bowl placed there), the fill is done. Turn the machine off, and restore the autofill to its normal postion.
- Let the machine descale hot for several hours. If doing the HX, you can do that while this is happening.
- To rinse the boiler afterwards, repeat this entire process, including the overfilling and running water through the steam arm once.
-Repeat the emptying of the boiler through the water tap, and ordinary refill (no extra water) until the drained water is tasteless (for me this happens on the second round -- your results may be different)."
Phần giải thích nguyên lý của cái cảm biến hay công tắc mực nuớc (Auto fill sensor) ở duới, bác sẽ dễ dàng thấy nó vì chỉ có mình nó có phần dây điện đi vào hộp điều khiển - bác tháo giắc ra nối tắt vào vỏ boiler (nghĩa là nối với tiếp đất) thì nuớc sẽ không bơm vào boiler, nếu tháo giắc ra bỏ lửng (không tiếp đất) thì bơm nuớc sẽ chạy và mở van điền đày nuớc vào boiler, chú ý canh không nuớc sẽ tràn ra ngoài.,
"The autofill is a "normally closed" switch. This means when the sensor is grounded, normally by making contact with the water in the boiler, and does pass current, it does NOT refill. If it is not grounded, it DOES refill.
- To prevent it from overfilling, one can remove the wire from the top of the wire and ground it on the boiler case (or use an insulated wire with alligator clips on the ends to ground it). Do this when descaling the HX circuit
- To force it to fill, once can simply pull the wire off, and let it hang in the air. Do this when overfilling the boiler. Use the machine's on/off for control. When overfilling the boiler, make sure the machine has reached operating temperature on the regular boiler level, since over filling it when the vacuum breaker is open will be very messy!
- If you plan to descale regularly, attach a 3 position "descaling switch" to the autofill circuit. Cut the wire running from from the brain box to the autofill wand. Attach the wire from the logic box to the middle terminal. Attach the wire to the autofill wand to one of the outer terminals. Attach a wire to ground (there's ground terminals on all machines, or stick it on the piping, if you don't trust your house wiring) to the other outer switch terminal. When you switch this to ground, the autofill never works, when you switch it to the wand, it works normally, in the middle position it just keeps filling. This switch can (and should) be left inside the machine, since one doesn't want to operate it inadvertently. Any small Radio Shack low voltage switch (1 amp is plenty) will work, just make sure it's designed to operate up to 250F.
- If you don't understand or don't want to understand these instructions, my advice is to learn how the machine works before doing this, or not to attempt descaling, and use softened water instead.
The descaling solution of choice is 1.5 to 2 table spoons of citric acid powder per liter/quart of water. It is at proper concentration if you see a light blue/green tinge in the flushed water when descaling. The reason this is the choice is that some citric acid will remain in the boiler when you descale that, unless you can drain it from the very bottom. Citric acid is odorless and, in low concentrations, tasteless, so it ill not mess up your steaming to have a little left. The alternatives are not as good: Vinegar smells, and industrial solutions (as well as CLR) are based on hydrochloric acid and are not food safe -- they would require a lot of extra rinsing flushes to remove."
Chúc bác thành công.,
Edit: nếu máy của bác có van xả boiler ở đáy thì sẽ nhàn hơn rất nhiều và boiler sẽ đuợc xả sạch dung dịch tẩy nhanh hơn.,