Commercial Storage Water Heater Installation Checklist

Location

• Install the heater as close as possible to the main hot water outlets and near the power supply and a floor drain.
• The ambient temperature must stay above 0 °C for indoor units. Do not install floor-standing units where freezing can occur.
• Outdoor installation requires a well-drained base and protection against wind, rain and direct sun; the unit must never stand in water.
• Leave enough space to remove the whole heater and enough clearance above it to replace the anode rod.
• Minimum service clearances given in OTTMEL instructions: 30 cm at the back and sides, 50 cm at the front.

Gas units

• Keep flammable and explosive materials at least 500 mm away from gas-fired heaters.
• Indoor gas models must be installed in a well-ventilated space; outdoor models must be installed outdoors, with the flue outlet not facing windows.
• Flue pipes must be rated for at least 120 °C. Outdoor models do not need a separate flue.
• Size the gas pipe according to the model’s technical data table.

Water piping

• Use rigid pipe rated for at least 0.85 MPa for the hot and cold water lines.
• Fit a shut-off valve on the cold water inlet and keep it open during operation, with a check valve between the shut-off valve and the heater.
• Pipe the T&P relief valve discharge to a floor drain, ending no more than 150 mm above the floor. Never fit a valve on the discharge line or block it.
• Use thread sealing tape on pipe joints, and do not overtighten the relief valve.

Commissioning

• Fill the tank before switching on: open the hot water outlet and a mixing tap, then open the inlet valve. When water flows steadily from the outlet, the tank is full.
• Check all connections for leaks.
• Make sure the unit is reliably earthed before connecting power.
• Disconnect power before any maintenance. Only qualified personnel should adjust or repair the heater.