Beer set point issue

Hello guys,
Been using brewpi for a while, just for logging mainly, but finally got around to doing the full build out and using it to actually control temps…
My issue is I have my beer setpoint at 71 F but the beer will just not get there, it is hovering a bit below at 70.7 Don’t get me wrong, I am not complaining because it is holding it very steady, it’s just not exact. Is this normal behaivour that it stay a bit below? My PID values are kp 1, ki .027, and kd 0.
Here is a screen of my current graph. Any suggestions?

In all reality. 70.7 is 71. At least it’s so close that its within the realm of the tolerances of the temp probes. If you were using Celsius you wouldn’t even have the amout of decimal places available to see that minute of a difference.

I agree, it’s not enough difference. Although I reset my PID parameters back to default and it is holding rock steady now!
Now I just need to figure out the LCD garbled when the relays trigger issue!

I’m waiting for my current brew to finish and then going to try and sort out my garbled LCD the goes crazy when the relay triggers… Mines not an official Brewpi though.

Kp was very low in your settings. Kp=1 means that when the beer temp is 1 degree too low, the fridge setting is beer setting + 1.

Ki (the integrator constant) normally corrects steady state errors, but it is only active when you are close to the set point (0.5C), to prevent integrator windup.

May I also ask about the power of your heater? It looks powerful, the lines are almost going straight up. You might be heating the minimum time at each spike. Around 60W is ideal for a normal household fridge.

mikmonken - Mine is not an official either. Let me know what you figure out.

Elco - The heater is a very small space heater made by lasko.

I am running my first profile starting a couple of hours ago. This profile starts at 68 degrees and after chilling my wort was at 65 degrees. Why is it not trying to get the beer to the setpoint of 68? is it a slow gradual thing? Here is a screen shot.

When posting screenshots, enable your fridge setting and beer setting line.

The fridge setting is the result of the PID algorithm on the beer temperature, the actuators work to get the fridge temp towards the fridge setting. If you want it to heat more, you should increase your PID parameters (Kp, Ki, Kd). Keep their ratio the same.

I can see that your heater is heating the minimum time and is overshooting. It is a bit powerful for such a small room.

I tried to attach a screen shot with the fridge and beer settings but it is telling me I cannot post to host… My current KP,Ki, and Kd settings are 5, .25 and -1.5.
What do you suggest I set them to?