Product Description Underground Tank Mains Fill Up The level control panel comes complete with transformer, rollerball float switch, and WRC approved brass solenoid valve. 3/4″ – 1″ Male Tundish + Pipework not included . When used in conjunction with a tundish, this is ideal for mains water top up to an underground tank. Available in 1/2″ 3/4″ & 1″ This is ideal for a mains water top up to an underground tank. Cable to solenoid and float switch are low voltage 24 VAC; main box with transformer requires a 230V supply.