Baxi 105 will have a 'filling loop' under the boiler. It connects the mains water to enter the central heating water.
Open the valves on each side of this loop and you will hear the water entering. WATCH the pressure rise on the meter under the flap at the boiler bottom!! Raise this pressure to 1 - 1.5 Bar, & close the valves. It may need more than one go to replace a radiator.
Steve
March 2008
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