Hot water boilers include electric, oil, gas, and coal-fired hot water boilers, among others. Hot water boilers are heating equipment that utilizes fuel combustion or other energy sources (such as electricity or solar energy) to heat water to a specified temperature. The "Special Equipment Safety Supervision Regulations" define boilers as devices that use various fuels, electricity, or other energy sources to heat the contained liquid to certain parameters and output thermal energy. The scope includes pressure steam boilers with a volume of 30L or more; pressure hot water boilers with an outlet water pressure of 0.1MPa or more (gauge pressure) and a rated power of 0.1Mw or more; and organic heat carrier boilers. Excerpted from the "Special Equipment Safety Supervision Regulations" of the People's Republic of China.

After cleaning the hot water boiler, dust (including flue dust) should be removed. The following points should be noted during the dust removal operation:

(1) Before ash cleaning, open the flue damper for thorough ventilation. Ash removal should be carried out sequentially from the high-temperature area to the low-temperature area.

(2) Pay special attention to areas where smoke flow is difficult to reach, such as blind spots and the bottom of the chimney where soot accumulates.

(3) Freshly scraped ash must not be watered near hot water boilers. The ash discharge area should be kept away from flammable materials.

After external cleaning, the chimney should be inspected as follows:

(1) Is the heating surface thoroughly clean, and are there still residues of soot and moss in the flue and chimney?

(2) Has the damage and loose parts of the brick wall been repaired? Repair the corrosion, loosening, and wire ropes of the chimney.

(3) Are there any damages to baffles, partitions, etc.? This may lead to a short circuit of smoke.

(4) Ensure that the filling material between the hot water boiler body and the brick wall, as well as the filling material in the expansion gap, is completely filled.

(5) Has the brick wall fire-resistant material absorbed moisture?

(6) There are no leakage traces on the pipe joints, pipes, and brackets of the hot water boiler body.