--- title: "Smeg DESCALING NEEDED: time for the built-in's scale cycle" description: "What DESCALING NEEDED PRESS OK TO START (~45MIN) means on Smeg DESCALING NEEDED: time for the built-in's scale cycles, what to check before booking, and when it…" url: "https://coffeemachinerepair.center/error-codes/smeg-descaling-needed/" --- # Smeg DESCALING NEEDED: time for the built-in's scale cycle Scale forms in the thermoblock and valves as water passes. ## What DESCALING NEEDED PRESS OK TO START (~45MIN) actually means. Scale forms in the thermoblock and valves as water passes. The Smeg built-in sets its reminder from the hardness you enter using the test strip, and prompts when a cycle is due. Smeg coffee machine display · also shown as DESCALING NEEDED What to do when DESCALING NEEDED PRESS OK TO START (~45MIN) shows on the coffee machine ### Kind of code Mode, not a failure The machine is doing what it was set to do, not wearing out: a rinse that runs through the spouts at switch-on and switch-off, a descale or filter reminder counting the water that has passed through, an energy-save mode that darkens the screen after a quiet spell, or a demo mode left on from the showroom that lights the keys and pours nothing. No part is needed; finishing the cycle the display asks for, or a key sequence from the manual, ends it. ### Usually leads to No repair Start it with OK, or put it off if you are about to make drinks. ### Shows up as What a Coffee Machine Error Code or Warning Symbol Means A coffee machine error code may show as a short string of letters and numbers, a flashing symbol for water, grounds or the brew unit, a short sentence on a text display, or a machine that stops with one light blinking. ### Make Smeg A Smeg espresso machine is repaired at the owner's kitchen counter after a single test shot shows where the trouble begins. ### Source Smeg automatic built-in coffee machine instruction manual (linked from the US CMSU4303X, CMSU4104S and CMSU2104G pages) Smeg US built-in automatic coffee machines CMSU4303X (Classic, listed as retiring), CMSU4104S and CMSU2104G (Linea). All three link the same instruction manual, and the message appears on the full-touch display in capitals. ## Before you book, in this order. Each step comes from Smeg's own guidance for DESCALING NEEDED PRESS OK TO START (~45MIN) on its coffee machines. Follow it to the end: the last card says whether this is a visit. 01 Start it with OK, or put it off if you are about to make drinks. 02 Use a descaler Smeg approves, set a large container under the spouts, and follow the display through the descaler run and the fresh water rinse. 03 If the prompt does not go away after a complete cycle, book a visit. ### Cleared? The message is gone, and the machine grinds, heats and pours a full cup again with no new part. If it comes back within the week, or the descale or filter reminder returns straight after a finished cycle, say so in the booking. ### What not to do It is not a sign of a breakdown; the machine still brews if you postpone it. A request for a third rinse means the tank was not filled to MAX for one of the rinses. ## What you may notice with it. The coffee machine problems DESCALING NEEDED PRESS OK TO START (~45MIN) tends to arrive with. Answer these at the coffee machine before anyone is booked. [All problems](https://coffeemachinerepair.center/problems/) Before you call ### [What a Coffee Machine Error Code or Warning Symbol Means](https://coffeemachinerepair.center/problems/coffee-machine-error-code/) [All 7 causes, cheapest first](https://coffeemachinerepair.center/problems/coffee-machine-error-code/) It also comes with - [**Coffee Machine Descale Message Will Not Go Away**](https://coffeemachinerepair.center/problems/coffee-machine-descale-message-wont-clear/) - [**Coffee From the Coffee Machine Not Hot Enough**](https://coffeemachinerepair.center/problems/coffee-machine-coffee-not-hot/) Problem ### What a Coffee Machine Error Code or Warning Symbol Means 7 causes, cheapest first No repair indicated ## Nothing to repair. The machine is doing what it was set to do, not wearing out: a rinse that runs through the spouts at switch-on and switch-off, a descale or filter reminder counting the water that has passed through, an energy-save mode that darkens the screen after a quiet spell, or a demo mode left on from the showroom that lights the keys and pours nothing. No part is needed; finishing the cycle the display asks for, or a key sequence from the manual, ends it. [How to read what your coffee machine is telling you](https://coffeemachinerepair.center/problems/coffee-machine-error-code/) ## Smeg coffee machines. A Smeg espresso machine is repaired at the owner's kitchen counter after a single test shot shows where the trouble begins. [Smeg coffee machine repair](https://coffeemachinerepair.center/brands/smeg/) More Smeg codes [FILL WATER TANK WITH FRESH WATER](https://coffeemachinerepair.center/error-codes/smeg-fill-water-tank-with-fresh-water/) [EMPTY GROUND CONTAINER](https://coffeemachinerepair.center/error-codes/smeg-empty-ground-container/) [GROUND TOO FINE. ADJUST GRIND LEVEL 1 CLICK WHILE IN OPERATION](https://coffeemachinerepair.center/error-codes/smeg-ground-too-fine/) [INSERT BREWING UNIT](https://coffeemachinerepair.center/error-codes/smeg-insert-brewing-unit/) [WATER CIRCUIT EMPTY PRESS OK TO START FILLING PROCESS](https://coffeemachinerepair.center/error-codes/smeg-water-circuit-empty/) [GENERAL ALARM: REFER TO USER MANUAL](https://coffeemachinerepair.center/error-codes/smeg-general-alarm/) [CLEANING PLEASE WAIT](https://coffeemachinerepair.center/error-codes/smeg-cleaning-please-wait/) [TURN THE MILK FROTH ADJUSTMENT KNOB TO START CLEANING](https://coffeemachinerepair.center/error-codes/smeg-turn-milk-froth-knob-to-clean/) [LED 30](https://coffeemachinerepair.center/error-codes/smeg-led-30/) [LED 31](https://coffeemachinerepair.center/error-codes/smeg-led-31/) [LED 29](https://coffeemachinerepair.center/error-codes/smeg-led-29/) [All buttons flash simultaneously](https://coffeemachinerepair.center/error-codes/smeg-all-buttons-flash/) [All 15 Smeg codes](https://coffeemachinerepair.center/error-codes/#codes-smeg) Mode, not a failure on other makes [Bertazzoni Descaling needed. Press OK to start (~45min)](https://coffeemachinerepair.center/error-codes/bertazzoni-descaling-needed/) [Bosch Please run Calc'nClean program!](https://coffeemachinerepair.center/error-codes/bosch-please-run-calcnclean/) [Fisher & Paykel DESCALING NEEDED](https://coffeemachinerepair.center/error-codes/fisher-and-paykel-descaling-needed/) [Fulgor Milano PLEASE DESCALE!](https://coffeemachinerepair.center/error-codes/fulgor-milano-please-descale/) [Gaggenau Cleaning and descaling](https://coffeemachinerepair.center/error-codes/gaggenau-cleaning-and-descaling/) [JennAir DESCALE!](https://coffeemachinerepair.center/error-codes/jennair-descale/) [Jura Too hot](https://coffeemachinerepair.center/error-codes/jura-too-hot/) [Miele Descale the appliance](https://coffeemachinerepair.center/error-codes/miele-descale-the-appliance/) [All 23 codes of this kind](https://coffeemachinerepair.center/error-codes/#family-mode) Smeg builds this ### Built-in coffee system The coffee machine set flush into a tall kitchen cabinet, filled from a water tank behind its front, grinding beans and brewing each cup on its own before sliding out on rails for service. Smeg builds this ### Countertop espresso machine The fully automatic bean-to-cup machine that stands on the counter, grinding, tamping, brewing and frothing at the touch of a key, with its tank, hopper and grounds drawer all reached from the top and the front. Smeg builds this ### Manual espresso machine The home espresso machine with a portafilter you fill and lock in by hand, a pump and a boiler or thermoblock inside, and a steam wand for milk you froth yourself. ## In Smeg's own words > Indicates that the machine must be de-scaled. [Smeg automatic built-in coffee machine instruction manual (linked from the US CMSU4303X, CMSU4104S and CMSU2104G pages)](https://doc.smeg.it/qr/914779197/EN) [Smeg automatic built-in coffee machine instruction manual (linked from the US CMSU4303X, CMSU4104S and CMSU2104G pages)](https://doc.smeg.it/qr/914779197/EN) [Smeg automatic built-in coffee machine instruction manual (linked from the US CMSU4303X, CMSU4104S and CMSU2104G pages)](https://doc.smeg.it/qr/914779197/EN) Every code on this site is taken from the manufacturer's documentation, never from a forum or a parts listing. Smeg US built-in automatic coffee machines CMSU4303X (Classic, listed as retiring), CMSU4104S and CMSU2104G (Linea). All three link the same instruction manual, and the message appears on the full-touch display in capitals. ## Smeg DESCALING NEEDED PRESS OK TO START (~45MIN) coffee machine repair, where we come out. 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Start it with OK, or put it off if you are about to make drinks. ### How long does a Smeg built-in descale take? The display estimates about 45 minutes; the descaler stage alone runs around 25, then comes the rinse. Stay nearby to refill the tank. ### Why does my Smeg ask to descale so often? Your hardness number may be set higher than your supply calls for. Dip the strip from the box and enter the number it shows. ### Can I descale a Smeg coffee machine with vinegar? Smeg asks for a descaler it approves and warns that an unsuitable one can cause damage. Vinegar is not on its list. --- **[Read on the site: Smeg DESCALING NEEDED: time for the built-in's scale cycle](https://coffeemachinerepair.center/error-codes/smeg-descaling-needed/)** **[Book a visit with CoffeeMachineRepair.center](https://coffeemachinerepair.center/schedule/)**