zozen boiler
Home Service FAQs FAQ of gas-fired(oil-fired) boilers How to clean the gas boiler?

How to clean the gas boiler?

26 Feb 2021

Pickling is the main method for removing a large amount of oxidizing substances and corrosion products inside a gas boiler, and also has the effect of eliminating scale. The pickling process is usually carried out after 1-3 weeks of boiler operation.

1.Cleaning tools

Boiler energy saver, steam drum, water wall, hydrochloric acid, ammonium bifluoride.

2.Cleaning method

1) First, at the beginning of the pickling work, the boiler's economizer, steam drum and water wall are filled with demineralized water.

2) The boiler is ignited. When the temperature of the boiler rises to 70-80℃, the boiler is turned off, and then the pickling operation can be performed. Before the pickling operation, the superheater should also be recharged with demineralized water until the water overflows into the steam drum to prevent acid or acid vapor from being introduced into the superheater.

3) When the acid is charged into the boiler, the boiler should not be ignited under any circumstances. The steam drum and other venting holes should be opened to remove the hydrogen generated by the reaction of acid and iron. Before making sure that the hydrogen has dissipated, avoid open flames or use electrical equipment that generates sparks to avoid the risk of hydrogen explosion.

4) Finally, after the acid filling is completed, let the boiler and economizer soak for about 6 hours in the solution, then drain the acid and rinse the superheater with demineralized water. The acid is discharged. After the acid is drained, the boiler feed water pump is operated, and the water of one economizer is filled into the boiler to prevent the water supply shutoff valve from leaking.

3.Matters needing attention

The gas boiler can be pickled with 5% hydrochloric acid with 0.25% ammonium difluoride inhibitor added. The acid solution is injected into the boiler through the pickling joint on the steam drum down pipe, and the acid filling of the economizer is carried out through the recirculation pipe. The filling of the acid solution should be carried out until the liquid level in the steam drum temporary water level gauge rises significantly until the liquid level rises above the cyclone separator, but it should be noted that the acid liquid cannot enter the superheater, otherwise it will cause serious damage.

Related news View More
  • ZOZEN Biomass Boiler Revitalizes the Plastic Foam Industry
    As global attention toward sustainable development intensifies, green and eco-friendly practices have become the main theme across all industries. For traditionally high-energy, high-emission sectors, technological innovation is essential to achieve clean production and unlock new growth. The plastic foam industry, a vital part of industrial manufacturing, has long faced the dual challenges of high energy consumption and environmental pressures. The emergence of biomass boilers offers a new gree...
    17 Jun 2025
  • ZOZEN Boiler Supports Poultry Farms in Kyrgyzstan
    With the ongoing advancement of the “Belt and Road” Initiative, economic and trade cooperation between China and Kyrgyzstan has become increasingly close. In February 2025, the two countries announced the launch of negotiations on a service trade and investment agreement, injecting new momentum into their bilateral collaboration. Against this backdrop, Chinese industrial equipment is making its way into Kyrgyzstan, helping local businesses grow—ZOZEN Boiler stands out as an exe...
    10 Jun 2025
  • ZOZEN Boiler Showcases Multi-Dimensional Energy Solutions at Serbia’s TOPS 2025 Scientific Symposium
    From June 2 to June 3, 2025, the TOPS 2025 Scientific Symposium, hosted by the Serbian Heating Association, was held in grand fashion. As one of the most influential events in the European heating industry, it attracted leading international brands such as Weishaupt, Bosch, and KSB, with a collective focus on cutting-edge technologies in gas and biomass boilers. In light of rising energy costs, biomass boilers, with their outstanding cost-saving potential, became a hot topic of discussion. As th...
    11 Jun 2025

Find the Right Boiler For You

Name *

Email *

WhatsApp/WeChat

Products

Power/Capacity