It takes time to become a good plumber, i.e., he has to spend more time for his career to be successful. There are many areas where a water heater like "wet only plumber" & in "Gas Industries". In the first type work is done in homes such as fitting bathroom, sprinkler system. Second type is very sensitive. To work in a gas industry one has to first achieve Council of Registered Gas Installer Certificate. Some plumbers normally work in domestic areas such as leaky taps & blocked sinks etc. Normally whatever field a plumber chooses the basic thing he must know is Water Regulations & Building Regulation.
Visually water line repair examine the frozen pipe for signs of damage including cracks holes or breaks. Begin your quest in the areas that are located closest to cold area such as the outer walls and crawl spaces. The holes can be as tiny as a pinprick, so inspect the pipe closely.
If you need to add copper pipe make sure that you clean the old and new pipe by using sandpaper, inside and out. If it's not clean the solder will not flow into the joint. Another tip is to not over wrap the mail threaded pipe with tape, this can cause a leak. Twice around should be enough. Also, don't over tighten it.
Working on the gas lines is also a complex job that only a licensed plumber can handle because it is very dangerous. Small leaks can't always be detected by odor alone, but a licensed professional has the proper equipment that's needed to ensure that you don't have any leaks in the line.
If the area around the fan isn't clean and dry, or if dust or any sort of growth has accumulated on the blades or inside the exhaust duct, it may be a warning sign of excess moisture build-up. Clean the water line repair fan and area well. Then double- check that the fan is operating properly.
And the way to know what's sufficient? Well, until the work is done an the bill paid you won't know for certain, but this is the best that can be suggested and normally works very well.
In short, the emergency plumber you hire should be from a reputable company. If you think that you can rely on him then you should look for another one. An emergency plumber should be skilled and should be able to deliver quality services to everyone.