Grohthem wireless service 11 error

[Dave16]

We are now getting SERVICE 11 error on our Grohthem Wireless Shower.
When we use it the display says WAIT, it then runs for a minute or two then stops with the above error code.
Can anyone help us.
Many thanks.

 

[picasso]

11 means the hot water is too cold for the shower to work properly, do you have a hot water cylinder or running off a combi ?

 

[Dave16]

Thanks Picasso,
We have a combi.
I had the main unit witched off for about 45 minutes this morning, when I switched it back on and turn the shower on again, it ran for a minute then stopped with the display saying WAIT then it went to SERVICE 13 after another minute the shower ran OK. also should the tempiture indecated on the display be flashing all the time? I can't say I've noticed it before.

 

[picasso]

service 13 means the water is too hot, I would check the boiler is running properly (steady flame not modulating up and down) before looking at the shower as faulty.