The parts needed to fix a leaking boiler vary based on the cause of the problem, but cleaning products and a sealing product are typically necessary. If the leak is caused by a pipe, tools for removing it may be needed as well.
Rust is one of the most common causes of corrosion, and it should be fully removed before the boiler is sealed to prevent further corrosion. While there are a number of ways to remove rust from small items, removing it from a boiler often requires using a large amount of potentially dangerous chemicals, so expert help is typically advised.
Metal fatigue can also strike on newer boilers with thinner walls than boilers used in the past, and the types of cracks caused by metal fatigue might not be repairable using chemical sealers. A metal cover might have to be welded into place to keep the crack from spreading. Welding is a skill that takes a considerable amount of training, and it requires appropriate tools and safety equipment.
The piping that leads into and out of the boiler often causes leaks, but pipes are generally easier to replace than to repair if the needed part is still manufactured. In many cases, basic household tools are sufficient to perform this work.