Currently I brew with two 10 gallons coolers and a propane-fired converted keg.
I heat up the water for my mash in the brew kettle, pump it to the MLT as I stir in the grains. During the mash, I heat my sparge water in the kettle and pump to the HLT and then pump to the MLT as I fly sparge.
This works okay as long as I compensate for the temperature drop when I pump (about 20 degrees). I generally try to error on the high side as I can cool the water down but raising the temperature is obviously not as easy.
I'm considering adding an electric element to my HLT so I can bring up the temperature a bit if needed. I would like to stay 120v which I hope will work as I probably don't need that large of an element.
Would something as simple as this "bucket heater"
I've seen a few people mention this product but no one seems to have commented on it's use.
I have concern about melting the cooler and if I don't have to worry about making sure I shut off the element when the HLT is empty, even better. Ideally I would want something mounted permanently so I could keep the lid on the HLT.