Anode rod Biawar 21.3 x 700 mm 3/4" for water heaters (21822)

Replacement magnesium anode rod Biawar 21.3 x 700 mm with 3/4" thread is designed to protect steel water heater tanks from corrosion by acting as a sacrificial anode. The rod’s 21.3 mm diameter and 700 mm length fit heaters that require these dimensions and a 3/4" connection. Made for routine maintenance, this anode rod reduces oxidation of the tank lining and helps extend the operational life of domestic and commercial hot water boilers where a compatible anode connection is present.

Advantages

The magnesium composition provides effective galvanic protection for steel tanks, accelerating corrosion of the rod instead of the tank. The standard 3/4" threaded connection ensures compatibility with many water heaters that accept screw-in anodes. With its specified diameter and length, the rod reaches deep enough into the tank to protect a large portion of the interior surface. The design allows straightforward replacement during scheduled maintenance and helps maintain hot water quality by limiting rust formation.

Suitable for

• Domestic water heaters with a 3/4" anode port and compatible internal dimensions
• Commercial hot water boilers requiring a 700 mm sacrificial anode
• Routine maintenance and corrosion prevention of steel storage tanks
• Replacement of worn or consumed magnesium anode rods

Key specifications

• Material: magnesium anode core
• Diameter: 21.3 mm
• Length: 700 mm
• Thread type: 3/4" screw-in connection
• Function: sacrificial corrosion protection for steel tanks

How to use

Turn off the water heater and isolate electrical or gas supply according to the manufacturer's safety instructions. Drain the tank to the level below the anode opening if required. Unscrew the old anode rod using the appropriate tool, taking care to support weight and avoid spilling water. Insert the Biawar magnesium anode rod and screw it into the 3/4" port until properly seated and sealed. Refill the tank, restore power or gas, and check for leaks at the connection. Periodic inspection of the anode rod is recommended; replace it when significantly corroded or consumed.

Usage recommendations

For reliable protection, inspect the anode rod every 1–3 years depending on water quality and usage. In hard water areas or high usage installations, consider more frequent checks. Use appropriate sealing materials on the thread if required by the water heater manufacturer and follow all safety precautions when working with pressurized or energized equipment.