Everything you study online about boilers says you should officially scrub them.
If you leave a boiler dirty, then havoc ensues. A dirty boiler can absolutely overheat and catch on fire. The air filter can only stop so much dust from going into the system; Once the dust gets in the inner workings and the surance struggles to maintain heat, there is your fire hazard. Another opening is carbon monoxide. While the boiler strains to achieve the temperature control setting, the heat exchanger can crack. This releases carbon monoxide into the home, which is a tasteless, aromaless, and poisonous gas. The only way to detect it is through a carbon monoxide detector. The only way to avoid it is with official boiler cleanings. I am on top of it with boiler service. I have a Terrell, TX boiler maintenance and maintenance business that is amazing. They show up on time and do routine maintenance once a year. They check for dust, rust, and coercion. They change my air filter, scrub the inner workings, and inspect every itn top to bottom. Typically they find nothing. This most recent time there was just a small worn part. It only cost me about 300 bucks for the part and labor. I was blissful to spend money for it. I feel anytime they catch a boiler maintenance is ideal. That part could have absolutely graduated into total system failure. It is almost better when they catch something. That way I can justify it in my head that my boiler maintenance is a smart investment every year. I love all the benefits I get from it.
