Grohe Red Duo M not working suddenly

It sounds like it is overheating or it thinks it is overheating. Check the temperature of the water that you pull off with a digital thermometer. It may need a new temperature thermistor. It may also have a pressure sensing gauge.

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The LED will flash red. When the child lock is activated the LED shows a constant red light. ... The GROHE ChildLock LED is automatically reactivated when the GROHE Red function is not used for 5 seconds. The system also activates the potfiller function - press the lock icon for a second time and the LED will flash yellow offshore hosting

It's probably the outlet then. It should be 220v with a 13a fuse. Maybe the fuse is blown, breaker tripped?

If you have single handle facute one bad cartridge in the system may be acting like a mixing valve and allowing cold water to mix with hot not allowing water to get hot enough .

Sounds like either you tripped the 220 breaker in your household electric panel, or a fuse located on the oven's control board. (service man)

Limit message is when the output water set temperature can not be reached, this is normally when the incoming hot water to the shower unit is not sufficiently hot. Service code 20 is something else inside the unit that is faulty, it could be a number of faults. Try reset Power down unit and re-start, it will either say Wait or Priming, after that it should restart, hopefully it will work. If not, you could have a internal fault with: The mixer valve/motor, the flow control valve or motor, the flow sensor. If you have hot water from other taps, then the mixer valve/motor is the most likely fault. If you only have cold water only from the shower head with limit message it could be the Hot solenoid controlled valve is faulty. Good luck as there are no spares available!

if its new you should,nt have had to have spare parts fitted,sounds like the tap is faulty,take it back and have it replaced.if you change it and theres still a problem it looks like you might have to change the model

It is in the mixer system,you may have put in repair kits with new springs,diaphrams,and o-rings or seals(washers).

Hi, Ensure that all water is switched off from the mains incoming tap, and hot water turn off tap under your boiler if that's the system you have.
Next open both levers of tap to ensure no water coming out, then remove heads with adjustable spanner. (Anti clockwise). Take to nearest plumbers merchant and they will supply new washers. It is a good idea before putting heads back in! get some de-scale liquid and spray them until lime-scale removed.
Screw heads back in turn off both taps and re-instate water supply. Then open both taps to clear any air in system.
And that's it.
If you find the heads are in bad order then you can buy replacments cheap enough, Just ask your merchants advice.
Hope this helps Thanks Paul.