Since 2015, about 2 years, I use a Senseo 2 or 3 times a day almost every day. The indicator light is lit for months but I have not seen a real drop in flow only a few days ago. And a flow that lowers it means coffee shorter, since the quantity is managed by timing, not by a flow meter ...
So I had coffees that were starting to be rikiki ... the cleaning method is easy is explained below.
This Senseo machine has made between 1500 and 2000 cycles, mostly double coffees. It is a Philips Senseo model but I think the method can be valid for other brands.
Light limestone lit from 6 months: no way to turn it off but the coffees are good?!?
The indicator "limestone" is on since 6 month (so about 18 months after the purchase). This without finding a loss of flow but I still used the official anti-limestone (2 doses were provided with the machine). However, the light remained on. The official anti-limestone is, in fact, citric acid powder ... (and certainly sold 10 times more expensive under the Senseo brand that it costs otherwise ... but here is not the debate).
I then made 2 or 3 reservations with pure white vinegar ... no better result: the indicator is also lit. I did not insist: the flow is good.
One can still wonder on which physical criterion this indicator limestone is lit ...
In any case it is not a measurement by pH probe which extinguishes it nor a pressure sensor ... can we suppose a simple count of cycles thus based on any real physical quantity of scaling? Maybe ...... Just to scare the housewife? I would be interested to know how to turn it off anyway!
The flow (and size of my coffees) drops sharply a few days ago!
But the flow has begun to fall seriously and sharply in recent days ...
So I looked at the problem and the solution is, in my case, very very simple! And I suppose that's the case in a lot of Senseo, which ends up being thrown or really broken down by the deletion instead of just being cleaned up ...
Indeed; it's not the inside of the Senseo machine that gets dirty but just the cup!
Here is the difference between a fouled cup and a clean cup:
It is clear that the small hopper in the center is dirty. The method is to clean this hopper ... simply!
A simple cleaning of the vinegar cup is enough!
The method is to rub lightly this hopper and to pass vinegar in it, there is a check valve calibrated to keep the coffee capsules under pressure, the flow "in the atmosphere" without pressure will be at best a drop to taste. The flow is about 2 or 3 drops per second when it is clean.
After 5 or 6 "vinegar" cycles, then 3 or 4 hot cups of water to rinse the cup of vinegar... the cup is clean and ready to be reused!
This method of cleaning is all the more interesting, in the end, this fouling will make work the pump more strongly, which may greatly limit its life ... and create a breakdown so much more expensive to repair (and in most cases it is not ...)