The instant (tankless) water heater heats the water at the moment of use — there is no tank. It saves space and energy and provides endless hot water. Its drawback: a higher purchase cost and reduced efficiency if more than one bathroom is used at the same time.
Instant heaters rely on a very powerful element (electric) or a rapid burner (gas) to heat the water as it flows through. Their components: a flow sensor, the heater, and temperature sensors. The most common faults: a clogged flow sensor, scale buildup on the heater, or weak water pressure. The most common brands: Rheem, Fresh and Ecomatic.
The most frequent faults we encounter while servicing Instant — ranked by occurrence.
A clogged flow sensor — the heater does not detect the running water
Limescale buildup in the heating coils
Weak supply water pressure preventing the heater from running
A faulty temperature sensor (NTC)
A faulty electronic control board
A clogged inlet water filter
Cleaning and inspecting the flow sensor
Removing limescale with specialized agents
Replacing the temperature sensors
Checking and improving the water pressure
Replacing the control board
Installing a new instant heater with all safety connections
The instant type heats on demand (no tank), while the standard type has a tank that stays hot all the time. The instant type is more economical on electricity but more expensive to buy.
If 2 bathrooms are used at the same time, then no. The instant type loses efficiency with simultaneous use. Consider 2 heaters or a large standard heater.
Very important. If the pressure is weak, the heater will not run at all. The minimum is 0.3 bar.
A lot. Because water enters and leaves quickly, scale builds up fast on the heating coils. Internal cleaning every 6 months is essential.
6-10 years. Less than the standard type because the electronic components are affected by the constant heat.
On-site diagnosis, clear pricing before any work, and a 6-month written warranty.