Different pipes for different purposes
Constructing your plumbing and drainage installation, isn't as straightforward as it may seem. First thing you need to choose, is what type of pipes are you going to use? There is plenty to choose from, but not all are multi purpose and good for your home.
Generally speaking, you need the ones relatively easy to install, repair if needed and with long life span. Price is also relevant, of course, but sometimes it is better to pay up more up front, rather than upgrade it later.
The answer to such problem is only one - PEX pipes. You might thought that copper pipes are better, but they aren't - harder to install and much more expensive. All in all, pipes from PEX are very good, either for the plumber or user. The only thing that's left, is to find were you can get them cheapest, and in required diameters.
Few words about plumbing - Wikipedia
Plumbing (which comes from the Latin word plumbum, which means lead, as pipes were once made from lead) is the job of working with pipes, tubing and plumbing fixtures for drinking water systems and getting rid of waste. A plumber is someone who fixes or puts in piping systems, plumbing fixtures and equipment such as water heaters. Many plumbers are construction workers. The plumbing industry is an important part of every developed economy because people need clean water and safe ways to move and store waste.
Plumbing also refers to a system of pipes and fixtures put in a building to move water and the get rid of waste that is in water. Plumbing is different from water and sewage systems because plumbing system serves one building, while water and sewage systems serve a group of buildings or a city.
Managing a broken boiler
There are repair jobs, that almost anyone can do themself, but broken boiler isn't one of them. Boiling hot water and immense pressure - those are the things that define boiler, and also the things you should be wary of.
Calling in professional plumber isn't any shame in this case, it is necessesity. It is different from a ticking bomb, but close enough, especially if the safety valves are at fault. All in all, you need expert on this - let him do his job, and relax. He is aware of the risks involved and already knows how to avoid any mistakes. All you need to do is coffee and maybe some snacks, while he do his job.
If you are not convinced by this, and ready to repair you boiler alone, all i have to add is this: search the internet for movies of exploding boilers, I dare you.