A water heater is 4 connections that each need to be right: cold water, hot water, safety discharge, electricity. The compliant summary.
The connection diagram
The rules point by point
- New 7-bar safety valve group at every cylinder replacement, mounted directly on the cold inlet, connected to a trapped waste — its drip during heating is normal (expansion).
- Hard water or pressure > 5 bar: add a pressure reducer upstream (set to 3-3.5 bar).
- Electricity: dedicated 2.5 mm² circuit / 20 A breaker + off-peak contactor to heat at cheap-rate hours.
- Dielectric unions on the hot side: they block galvanic corrosion between copper and steel.
- Fixing: a full 200 L cylinder weighs ~250 kg — on plasterboard, through-reinforcement or a floor tripod is mandatory; see fixing heavy loads.
- In a bathroom: only outside zones 0/1 (or a small protected instant heater in zone 1) — see the zones.
The maintenance that doubles its life
- Operate the safety group once a month (small knob) against scaling.
- Anode and tank: check at 4-5 years in hard water; set the thermostat to 55-60 °C (anti-legionella AND anti-scalding).