Speidel Braumeister Temperature Wobble

[casalingo_brewers]

Hello Brewers,

We have observed that our Speidel Braumeister (20L) does not keep the temperature constant.

Example: For the maltose rest, I set a target temperature of 63?C over 1 hour.
What happens: The temperature reading of the system bounces from 61 up to 70 degrees!
Effect: my beers turn out sweeter than intended.

This seems to be a rather new development that we did not have when it was new. We have brewed 130 batches over 6 years.
The system is standing in a dry place but exposed to frost in the winter, down to -15?C.

Any ideas?
Has anyone observed anything similar?

Cheers,
Andreas

 

[casalingo_brewers]

update (which I should have sent a while ago):
Speidel sent me a new controller for the Braumeister system. Now works as good as new!
Apparently some semiconductor-switch wears out and allows surface-currents that get in the way of proper controlling temperature.
-> if you observe this with the (older version of the) Speidel-Braumeister, just contact them. Easy enough