摘要 |
<p>Method and apparatus for operating a closed hot water installation provided with a pipe system, a boiler, heat exchangers, an expansion tank, a water make-up provision and a de-aerator, the method including the steps of opening a non-return valve to allow air to escape, detecting a water level in the de-aerator, feeding water to the closed installation when the level falls below a predetermined level, blocking opening of the non-return valve until the water level has fallen to a first level and starting the feed of water when a second lower level is reached.</p> |