I also have this problem and noticed that the difference is double (or half) of what is expected.
tuning again and again did not change much, but it looks like you're already fixing the problem

I have a suggestion: could you add a feature that makes it possible to zoom in on the temperature chart (as in temporarily increase the window size or open in a new window)?
The way it currently is makes it impossible to see small changes, but I would be interested in seeing them.
I think it would make it possible to see changes when feeding too fast or having air flow etc

I also have this problem and noticed that the difference is double (or half) of what is expected.
tuning again and again did not change much, but it looks like you're already fixing the problem

I have a suggestion: could you add a feature that makes it possible to zoom in on the temperature chart (as in temporarily increase the window size or open in a new window)?
The way it currently is makes it impossible to see small changes, but I would be interested in seeing them.
I think it would make it possible to see changes when feeding too fast or having air flow etc

@phaedrux omg, I just noticed this reply

ok, so this means I can not hide or remove one completely? (since it shows the one and only installed fan twice)

I know this topic is kinda old, but I have the same problem since I switched to RRF3.

Since then I see the same fan twice, but I don't know how to get rid of "Tool Fan" and just show it as "berdair".

I have

; Fans
M950 F0 C"out7" Q18000                                ; create fan 0 on pin out8 and set its frequency
M106 C"BerdAir" P0 S0 L0.0 X0.7 H-1 B0.1 

; Tools
M563 P0 S"Volcano" D0 H1 F0 

T0

Why do I still see 2 entries for one fan?

wow, this time it finished fast (after 5 idle and 5 tuning cycles in 605 s) with no warning! Nice!
Thanks
Have a wonderful Christmas

@jay_s_uk said in New heater tuning algorithm:

did you tune as H1 or T0?

finally I have some time to update and reply:
I usually tune using H0 and H1.
I'm working with Duet3 and RRF for the first time, so basically I am a noob

I added the F0 back to the tool definition g-code line.
I just wonder why I suddenly see 2 fans defined after I switched to the new (beta) firmware branch. I didn't see any clue in the release notes though.

Right now I try to tune my bed heater again, maybe the warning won't appear this time.
BTW: I still have the previous PID values stored, but I don't know if I can simply use them with the new firmware.

alright, I just registered to participate

I also have a "bigger" heatbed/plate with a 1400W heater.
Since I switched to the new firmware, the PID tuning result is different.
For the heatbed I always get the warning that others get, too: heater behaviour is not consistent during tuning.
Before I wrote this post, I updated to the new beta 4.1, since I read above that dc42 changed the algorithm again for bigger beds, but the results are nearly the same for me.

Oh, the fan doesn't start while tuning. Since I switched to the new fw I have 2 fans listed: tool fan and the one I named "berdair", which actually is the air pump I have installed. The tool fan does not exist. I can't find the gcode in config.g that creates the "tool fan" though.

Under "Fans" I have 2 lines:
M950 F0 C"out7" Q18000
M106 C"BerdAir" P0 S0 L0.0 X0.7 H-1 B0.1

Under "Tools" I removed the F0 from the M563 command without any effect.
So it's just
M563 P0 S"Volcano" D0 H1 ;F0