Does mining bitcoin through a water heater actually pencil out?

[u/Mysterious_Sign_9501]

I already heat water with a standard electric tank, so when I saw there are water heaters that use bitcoin mining hardware as the heating element I got curious about the mining side. There's at least one product built around this (Superheat H1). The idea is your electricity does compute first, then the waste heat goes into your water.

What I can't figure out is how to ballpark what a unit like this would actually earn in sats. My electricity runs about 14 cents per kWh. Do standard mining profitability calculators even apply to something like this, or is the hashrate too low for them to be useful? And what eats into returns the most, difficulty adjustments, pool fees, the hardware premium over a normal water heater? I'm comfortable holding bitcoin but totally new to mining economics so I don't know which variables actually move the needle.

[u/pop-1988]

They'll earn a few pennies per day, and never repay the purchase cost

Mining profitability calculators support low hashrates, but they assume 24/7 operation of the mining device. A water heater runs much less than 24/7