[kgs]

So I came home tonight (Wednesday) to a distressing discovery. On Monday morning I finished brewing a rye IPA and put it in my Danby fridge with a Johnson single-stage controller plugged into a Brewer's Edge space heater in the fridge. The fridge was unplugged. That night the temp seemed fine -- ca. 66 degrees. Same the next morning. I got busy and did not check last night or this morning--usually I let beers "be" while they brew. I came home tonight and the controller read... 100f. Naturally I quickly unplugged the controller and opened the fridge door. Predicting this won't be my best batch of beer.

The only thing I can think of is I didn't set the jumpers from cooling to heating. The next thing on my list is did the controller fail. (I also checked that I had the "right" things plugged in.) The temp in the house has been in the low 50s to mid-60s, so that's not an issue. I also had the "right" cords plugged in the right places.

I'm headed to a conference tomorrow so I'm mulling over whether to plug the fridge back in, turn it to the highest temp, and let things finish out in the high 50s (no controller, no heater). I don't have the time tonight or tomorrow to test the controller.

Me sad... but, it's beer. I can brew again.

[TeeDubb]

Sounds like you had the logic reversed on the controller.  You should be able to quickly check that by plugging in a lamp and place the sensor in a glass of water near the setpoint and adjust it up and down with additional hot and ice.

If the temp sensor was just sitting in the air around the fermenter, I doubt the beer got as hot as the air around it in that short timeframe. The batch may not be a goner if it just got into the 70's (depending on the yeast you're using).

With your ambient temps, you may need to cool and not heat during the early phases of fermentation. Just a hunch with no other info.

If pressed for time, I would leave everything disconnected and crack the door on the fridge.  Mid to low's 60's in the house plus a little heat from fermentation may keep your beer in the high 60's during the early and vigorous part of fermentation.

[kgs]

Sounds like you had the logic reversed on the controller.  You should be able to quickly check that by plugging in a lamp and place the sensor in a glass of water near the setpoint and adjust it up and down with additional hot and ice.

If the temp sensor was just sitting in the air around the fermenter, I doubt the beer got as hot as the air around it in that short timeframe. The batch may not be a goner if it just got into the 70's (depending on the yeast you're using).

With your ambient temps, you may need to cool and not heat during the early phases of fermentation. Just a hunch with no other info.

If pressed for time, I would leave everything disconnected and crack the door on the fridge.  Mid to low's 60's in the house plus a little heat from fermentation may keep your beer in the high 60's during the early and vigorous part of fermentation.

Unfortunately, the probe was taped to the side of the fermenter. That said I am away til next week and will just sit it out at low temps and see what happens. I'll test the controller when I'm home to see if I can replicate the problem (on a small bucket of water, not lovingly-handcrafted fresh AG wort). It looks as if the most vigorous stage of fermentation already happened (through the bucket walls I can see the "trub line" a few inches above the liquid line).

In the four to five years I've owned the controller I have never changed the settings other than to adjust the target temp (setpoint) or occasionally tweak the differential one or two degrees, but obviously reviewing the settings is a good idea, in case I accidentally canoodled with some setting other than setpoint. I plan to get a two-stage controller, though with this lesson, I will test-drive it as well.

[Delo]

I think the default setting for the jumpers is for cooling and you need to switch the jumpers to use a heating source.  Is this the first time you are using a heater with the controller?

[kgs]

I think the default setting for the jumpers is for cooling and you need to switch the jumpers to use a heating source.  Is this the first time you are using a heater with the controller?

Yes, it is. *Learning commences*