I've just recently started having problems with my Brewtus IV. The temperature display jumps around, displaying 99C then a second later 104C then perhaps 103C then 107C, etc etc.

The temperature is is set to target 94 degrees C. I have reset the PID settings to factory defaults, though I had never adjusted the temperature offset.

My machine is currently descaling, and has been soaking for over two hours now, yet it still shows no signs of the problem going away.

Any thoughts on what I can try doing before taking the more expensive option of taking it to a coffee tech?

Thanks.

If you KNOW what a DVOM is and KNOW your way around wiring/diagrams; check the PID connections, especially the ground. If not, off to the shop it goes.