As a rule of thumb, if your water supply is normal water also known as fresh/ soft water, you can pretty much use any model of instant shower that pleases you; without worrying about damaging the heating element.
-8%
With Pump
LIRLEE Tankless Heater With Pump Instant Shower + HAND SHOWER – For Extremely Salty Water – OFFER!!!
Original price was: KSh 13,000.KSh 12,000Current price is: KSh 12,000.
-16%
With Pump
Original price was: KSh 21,500.KSh 18,000Current price is: KSh 18,000.
With normal/ fresh/ soft water, you can use any instant shower/ heater without worrying about the element. With proper installation/ use, a good quality instant shower will serve you for a very long time.