I should have the last piece I need to finish my repair/PID installation tonight and am looking for advice on setting the PId up.

My plan so far is to set Sv to a given temperature, perform an auto tune and then taste an adjust Sv... Does that seem reasonable? Do I need to try and check my brand new PId calibration first? (How?)

I would start at 225 F as that is the number I found by reading other accounts of putting a PID inside an Isomac Zaffiro. I realize this is just a starting point as my probe (a 20AWG stranded T type TC wire soldered to a cut off thermostat bulb inserted into the noiler's thermal well) and its position may differ from others'.

I don't have a fast good way to check the brewing temperature or even the temperature off the group during brewing (unless a wireless grill thermometer qualifies ).

What has your successful setup and calibration procedure been?

For a simple temperature control setup like yours, auto tune will work fine. It has to ramp the temperatures up and down a few times to figure how fast everything responds and then it sets the PID values you'll need. Don't add or pull water during this period of time.
The only time I've had to go in and tweak the PID values was for a very low air pressure setup for a building where the values bounce like crazy. I 'dumbed' the PID down a bit to preform in a more stable manner. With a heater in small boiler like yours, this shouldn't be the case.
The D value should be small and touched last. It could be 0 and control could work well. It prevents overshoot on very fast recovery times. Most times I never even use it, so it's 0.
The I value tells the logic how fast to recover from a set point error, again it can be a smaller value (than the auto-tune gives you.)
You'll be looking at the PV process value, to see what your boiler temp is. That's what you'll work with. If after auto tuning you're keeping the temp to within a degree or better, you are set up just fine. When you add or take water out of the heater, then watch to see how much if any overshoot from setpoint occurs. Then you may have to tweak further. The PID literature usually tells you more than you'll want to experience. IE a head ache.

Calibration is placing the sensor in an insulated coffee travel mug with a water slush (ice mixture), it's always 32F. Boiling water is 212. Calibration is not really needed but only for your amusement to know the the baselines are.
Put your wire grill thermometer in the same mixture to check it, but don't be surprised if its off a bit.

Good luck,
D.

Search "brew water temp measurement" and you will find ways of checking easily and cheaply.. ( poly cup and digi' temp probe)
Seeking low tech way to measure brew temperature
But final adjust to suit your particular blend and taste.

My plan so far is to set Sv to a given temperature, perform an auto tune and then taste an adjust Sv... Does that seem reasonable?

What PID did you acquire? Typical good practice would be to initiate the autotune procedure at around 10% below a reasonable Sv. So, in your case that would be 200-205.

You need to give the machine, in particular the grouphead, around 15-20 minutes to stabilize at any new setting of Sv. I would not count on discerning any wild differences between 225 and 226 but I would expect some differences between 225 and 220/230.

You could calibrate your "system" in a "bucket of steam" on your stove and correct for your altitude/then current barometric pressure.

Eric I got an Auber PID. The small 1/32 DIN

I believe those PID's have a default offset for autotune but, I suppose, it really doesn't matter if you set that default to zero and initiate autotune as I suggested or just operate the autotune with the defaults.

The manual does explain all of this, I believe . . . and certainly you need to tell the PID that you have a Type T thermocouple as the default is a Type K.

Alright! Everything is connected. I had to make one last run to the store to buy some flare nut wrenches since I had managed to move the thermal well nut a little, but did not want to keep rounding its corner when tightening it back. This another of my world famous expensive and slow repairs... but I learned a great deal and loved that. And I have more tools, I guess. I figure it's not the last time I'll need flare nut wrenches.

Eric I don't understand your comment about initiating auto tune at 10% below the desired Sv. I actually just read it again. I initiated auto tune at an Sv of 220 and the PID shows a Pv of 219 that doesn't vary much at all. If I initiated at 200-205, I'd expect it to stay at that. Did you then mean to auto tune at 200-205 and then set my truly desired Sv? Is that to prevent overshooting better?

It is to prevent any potential boiler damage - highly unlikely. But it also lets the PID "self-tune" in the area it will be operating.

Did you not see the menu item "ATDU" in the manual?

I did: "The autotune offset will shift the SV value down by the Atdu value during the auto tune process. That will prevent the system from damage due to overheating during the autotune."

But I did not know what to do with it... I figured that any temperature I would set for brewing would be way under whatever the boiler gets to during steaming. I did auto tune at 220 and then set Sv to 225 and its stable (like previously, at 224 mostly). What would you do with that parameter?

You really need to set Sv prior to the autotune process. Then, when you initiate autotune, that process would begin at 10 degrees below your chosen Sv. So, my advice would be to leave Atdu alone for now and write down the particular values the PID has set itself for P, I, and d. Once again, initiate autotune and see if the values change. The machine should be fully warmed up for an hour or so before you begin.

What would you do with that parameter?

I have typically set it to 0 and initiated autotune as previously advised or set it to 20 and let the PID autotune at Sv minus 20 . . . same result.