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Heating and cooling using 2 Johnson Controllers

Santa was good. Time to get exact with temp control. Here’s what I’ve got:
Johnson Digital Controller A419 (two of these)
Older upright freezer

For those familiar with the controllers, here are my setting (feel free to correct me if you think it is incorrect).

Controller 1 is connected to Fermwrap: Jumper set to heating mode, cut-out @ 68, Dif set to 1, ASd set to 1, probe is taped to the carboy. The goal with this setting is to make sure the heat will kick on if the temp dips below 68, and also shuts off at 68 .

Controller 2 connected to Freezer: Jumper set to cooling mode, cut-in @ 68, Dif set to 1, ASd set to 12 to prevent constant freezer cycling, probe is taped to the carboy. The goal with this setting is to make sure the freezer kicks on if the temp rises above 68.

I believe this SHOULD put my test carboy of 103 degree water at 68 and hold it there… As soon as I plugged the freezer in it began running, which is a good sign. Anyone use this? Overlooking anything with the settings?

I have yet to get my ferm chamber together from Santa (hasn’t been delivered yet) so take my analysis with a grain of salt. Are the probes between the fermwrap and the carboy? My concern is the probes will be detecting the temperature of the fermwrap and not the temp of the beer and thinking it’s warmer than it really is.

Any particular reason you didn’t opt for a dual stage controller? It’s about the same price as 2 controllers and will guarantee that only the freezer or heating element is on at any given time, plus it only uses a single probe.

You really should use a thermowell stopper if you are using a fermwrap but I have no idea if they sell thermowell stoppers with enough space for 2 probes. I’ve heard that you could just put the temp probe directly in the beer but it’s my understanding that those probes are “Water resistant” and not totally “Water proof” so they may lose accuracy over time.

Again, this is advice coming from someone who’s done some research on the topic but have no real practical experience with these things.

I was worried about the same thing with the fermwrap, but it turns out it only wraps about 3/4 the way around the carboy, leaving plenty of room for probes taped to the side and the fermometer that was already on the carboy. I’m pretty pleased with that, saves me from ordering a thermowell that won’t fit with the Big Mouth Bubbler that was also under the tree.
As for the dual controllers, chalk it up to first time messing around with this type of equipment. I shopped around a bit but thought the dual-stage would do either heating or cooling but not both without switching a setting. Could be totally wrong there. Update this morning: fermometer reads 68, heating controller reads 68, cooling controller reads 67. Slight calibration issue I s’pose with the 1 degree difference but nothing to worry about.

That’s good to hear! I’m very excited to get mine all setup.

I’m excited to try it out on some Belgian Ale this weekend. As a newer brewer (began last spring) it took me 11 batches of beer to figure out there is nothing wrong with my water or cleaning techniques, but I was not properly controlling fermentation temperature. Lots of disappointing brews in that time frame from runaway temps!

Yeast strain on the Belgian called for temp range of 65-76. I pitched yeast in 64 degree wort last night and set my controllers at 66. The fermwrap quickly brought it up to temp and the freezer has held the beer at 66 on the money even with active fermentation well underway now. Happy to have this level of temperature control… this should have been one of my first purchases. Looking around more I would probably pick up the Ranco dual controller… but so far I would recommend a controller setup to anyone on the fence. Very pleased.

For ales this time of year a single stage controller works fine for me (I use a thermowell). Set at 68F in a very cold garage, I am able to keep ales at 62-66F…YMMV, of course

I’m new to doing temperature control too. I’d like to put a thermowell into the Big Mouth Bubbler I just ordered. It uses a #5.5 stopper. Should I get a two-hole #5.5 stopper and put the thermowell in one hole, and the airlock in the other? Will this work?

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