Water heaters with mechanical control

Mechanical control

— control using various elements — rotary knobs, buttons, sliders — directly connected to the controlled elements of the water heater. For example, in a gas heater (see "Energy source"), the temperature control knob will directly control a valve that changes the amount of gas supplied (and, accordingly, the intensity of heating). Such control turns out to be extremely simple and cheap, but its possibilities are very limited, and the adjustment accuracy is usually much lower than in electronic systems.