Is a plumber required to be insured and bonded? Combi boilers are far less complex than traditional heating systems, which means that installations tend to be cheaper it is also easier to find replacement parts if a problem occurs. Get our monthly special offers, great deals and latest news - direct to your inbox! We'll come back shortly if we are open, or first thing when we open if outside of office hours. What is the best way to find a new plumber? There are two likely.