[Pi]

I am using a 240Volt, 4500 Watt hot water heater element to heat recirculating wort. When I raise the temperature on the PID controller, the relay closes the circuit and the heater is on constantly till it gets close to the set point. The the heater "pulses" heat so's not to overshoot.
Since I cant see the heater element, I am curious. When it's on constantly do you think the heater is getting red hot? Also note, I am applying 110, house current and the element is rated for 240. I recently did a decoction and got a stuck mash. I think if I throttle back the flow rate I could avoid this in the future, but have concerns doing so might scorch the hot liquor and/or denature the enzymes.
My beers are  turning out OK (aside from an attenuation issue- save that for another thread) I am just wondering what other RIMS brewers are using as a heat source. Thanks for your input

[dak0415]

I'm using the same voltage/wattage element.  What PID controller are your using, and where is the temperature probe in the wort stream?  As long as there is no air in the heater plenum and your wort is moving you should not have any problems with scorching.  Look at the guys on the forum who are using electric kettles.  If your element was getting red-hot the wort would boil and your rims tube would explode!

[Pi]

Omega CN8201 PID. I have it wired so the heat wont come on unless the pump is running. Like I said, I am not having any real problems- just thought it might be.Reassuring to see someone else is doing the same. Do you think slowing down the flow rate could be bad, or as long as their's liquid constantly moving past it shouldnt pose a problem?

[dak0415]

Again, where is the probe in the wort stream?  Mine is just at the output of the RIMS tube so as long as the wort is moving, the heater will shut off at setpoint.  The slower the wort, the more the overshoot but it's not much.

[Pi]

Probe is in the side of the MT right about the center of the grain bed. You think I should have it sensing the wort as it returns to the MT?

[mabrungard]

You will overheat the wort if the temp probe is not immediately downstream of the heating elements.  I've already played that game and its not pretty.  The wort is very dextrinous and unfermentable.  You end up inactivating all the enzymes in the wort eventhough you haven't heated the mash beyond your set point. 

[Pi]

Hmmmmm,
That could explain my attenuation issue! Thank you for your help. I'll let you know how things work out, but imagine you already know!!!