how far off the bottom should a herms coil be

I finally pulled the trigger and bought some/lots of nice stainless fittings from BrewHardware (thanks @bobby_m !) to set up my propane fired Keggle HLT with a HERMS coil over this past weekend.

while I was brewing on sunday, and fiddling with the temp control/figuring out how to actually use a HERMS coil, I noticed that that my HLT burner heat control had more impact on the recirc temp than the HLT's water temp (this is somewhat expected), but it got me wondering how far away from the bottom of the HLT should the coil be? I set it up to be pretty close to the bottom because I wanted to be able to use 5 gallons of water in the HLT and still cover the coil (ie, if I'm doing a 5g batch), but I wonder if being too close to the bottom is making temp control harder than it should be. it's definitely not touching the bottom or sides of the keggle at all, but it is close.


so.. how far off the bottom of the keggle should the HERMS coil be?


(sorry.. I didn't take very many good pics if this while I was brewing)

If your heating your strike water in your hlt, you want that coil as low as possible so it's still submerged when you are recirculating the mash.