What is a picking hole

 The selection hole is used to collect soot and ash from the chimney.  It is set up from the lowest point of the chimney. The smallest dimension in the narrow and medium passage is 120 x 250 mm and the holes are 450 x 600. Placed must be 30 - 100 cm above the non-flammable floor and the double sheet metal door of the picking hole is indicated by the type of fuel. According to the ČSN, it is not allowed to enter residential rooms, halls, classrooms and warehouses, where flammable substances, explosives, etc. are kept.  The selection hole is designed for both continuous and floor chimneys for solid and liquid fuel consumers, it must be at the level of the chimney flue. In the floor chimney, the vents are placed on the corridor, staircase or other common space. If they can not be placed here, they are placed in a hall, a chamber, a bathroom or a toilet. They may not be in the bedroom or in the children's room.  Also, do not connect from several vents to a common selection vent.