a swimming pool plant heating room with warning caution sign on the wall

swimming pool plant room heating warning sign outside caution keep locked shut unauthorized unauthorised access pipeworks pipework filtration equipment system indoor installation air conditioning water neat tidy organised detailed plumbing schematic intricate pattern maze piping tubes tubing circulation cleaning chlorine signage danger red unit boiler tank aluminum copper foil insulated insulation safety work human resources plugs sockets brick wall breeze blocks laid out complicated complex horizontal vertical entry big large white container vessel filter tube pump house forbidden banned