Johnson control won't rise to desired temp

[theintern43]

hey so I'm having yet again another problem with my Johnson control, so I set it to be at 66 and left for the grocery store, I came back and it reads 51, I even put a thermometer inside and that read 55 as well, I opened the chest freezer in hopes of the temp rising to what my AC thermometer is at 70 but still the Johnson is low at 61...and tips or tricks? I switched the chest freezer from the coldest setting to two notches away from coldest, any help?

 

[shanecb]

It's not set to "heat" mode is it? That would make it constantly run the freezer by accident driving the temp way down.

Can you share what all of your settings are on the controller?

 

[hunter_le five]

A Johnson controller can't "heat" a chest freezer.

If ambient temps can't make the temp in your chest freezer rise, you probably need to add some sort of heat source and a two-stage controller.

 

[Skiffy]

Where is your probe, what is the temp of the liquid when you put it in and what is your room ambient temp?

What is differential set to on Johnson controller?

Also I would recommend putting your freezer on its warmest setting

 

[shanecb]

A Johnson controller can't "heat" a chest freezer.

If ambient temps can't make the temp in your chest freezer rise, you probably need to add some sort of heat source and a two-stage controller.

I was interpreting the question as "the controller/freezer is driving the beer too low" and not "the beer won't rise to the desired temperature".

 

[hunter_le five]

I was interpreting the question as "the controller/freezer is driving the beer too low" and not "the beer won't rise to the desired temperature".

My response was directed at the OP's post, I hadn't actually seen your response yet.

But I see what you're saying. Perhaps the OP can clarify on the exact nature of the problem?

 

[shanecb]

My response was directed at the OP's post, I hadn't actually seen your response yet.

But I see what you're saying. Perhaps the OP can clarify on the exact nature of the problem?

Gotcha! All good, was just going to clarify what I meant.

Yeah, can you clarify theintern43 on exactly what the issue is? That would help us determine if it's a controller setting or if the beer just isn't rising to the desired temperature.

 

[theintern43]

for now the johnson control is staying at 68

SP-68
Df-1

my apartment is at 70

my roommate and I think it dropped so low because the chest freezer (7cubic yards) is just small so when the temp rises too high and the freezer kicks on it just drops the temp way low really fast

 

[hunter_le five]

How is the probe situated? Is there anything inside the freezer, or is it empty?

 

[shanecb]

for now the johnson control is staying at 68

SP-68
Df-1

my apartment is at 70

my roommate and I think it dropped so low because the chest freezer (7cubic yards) is just small so when the temp rises too high and the freezer kicks on it just drops the temp way low really fast

I don't really think that's the culprit. I have the same size of a chest freezer and never had this sort of issue. Is the probe insulated against the air of the chest freezer? Covered with bubble wrap or a towel or something, when it's attached to your fermenter?

 

[Skiffy]

If you put 90 degree liquid into the freezer and set it for 65 then yes it will over shoot since the air in the chest freezer will be much much colder than the wort once the wort hits the set point. Not saying you did that but just to make a point

Also remember that the probe is not designed to be submerged in liquid. I did not know that when I got mine.