Ferm Wrap Heater

How fast do these things heat up? I'm just now using one for the first time, and I've had it on for about an hour, but I don't really feel anything heating up when I put my hand to it.

Purchased this model: http://www.midwestsupplies.com/fermwrap-heater.html

Thanks

They don't get super hot to the touch. But, I'd think you'd feel something.

touch it next to where the wire connects to the fermwrap itself.

that's the first spot I can feel heat, and lots of times the other end of the fermwrap doesn't even feel warm to me.

but TRUST ME, if you plug it straight into the wall, without a temp controller, it will REALLY warm up your beer. I had to take mine off the fermenter, and let it sit next to it, barely touching about a 1" wide section.

Don't worry about feeling the heat. it works the same same way your rear defroster does in your car. You can have that on and touch the window but it doesn't feel hot. These work great IMO. But I use a thermowell with temp controller to set it and forget it.

Thanks for the replies. I checked it last evening and this morning, and it is definitely working. I'm curious about the temp controller now though. I've got a thermowell stopper, and my temp controller is set to 70* with a 1* differential. I expected that meant it would click off AT 71*. But it actually has to read past that to click off. So, the beer is reading as high as 72* and fluctuates down after that until it clicks back on. So, in practice, even with it dialed in tight, the temp fluctuates 3-4*. Is that pretty standard practice?

I guess I'd always figured it was the other way around with a temp controller. If you set it at 70 with a 1 degree differential, I would have thought it would cool to 69, then turn back on and heat to 70. At least it seems that way when I'm cooling, if I set it to 65 with a 3 degree temp, it will warm up to 68 before kicking on and then turn off at 65. Although I should say I've not actually watched it to notice, just that I've seen the temp read within 65-68 in that condition.

With the fermwrap, I suppose I could see where the beer on the outside of the carboy is getting heated, but the beer where the thermowell is located isn't, so you could wind up with a temp gradient from the outside in. Then once the fermwrap shuts off the heat begins to equilibriate, giving you higher temps than what you've got it set at. It depends on how vigorous your fermentation is too, at first I'd think there would be enough movement in the fermenter to mix the heat pretty well, but maybe after fermentation dies down its a bigger deal? Just a guess, I could be way off .

If I plug something else into it, like a lamp, I can see where it disengages. Heating up, the manual says it stops at set point + differential. However, it has to go PAST that. So it's really set point + differential + 1.