HCM heaters are designed around a helical coil that we produce in our own shop. All of our helical coils meet ASME code. The coil in our HCM heater carries a 5-year warranty. No one else matches our warranty.
Our helical coil has a life expectancy much longer than its 5-year warranty. This is extremely important where gaining access for replacement is a major undertaking. So, longer coil life saves much more than just the cost of a coil.