Plumbers are responsible for the installation, maintenance of plumbing systems for homes but also for public, commercial and park facilities. They have a thorough knowledge of the work in pipes and pipes (cutting, remodeling, manipulation, safety rules). This occupation can sometimes be dangerous, that is why it is necessary to call plumbers who have a good practical and technical training.
For the price: try to negotiate in advance, ask them what the payment methods are, if the work is large, it is normal to be asked to pay them a part at the beginning. Find out in your neighbors (family, friends) the estimated prices. Also, if you think that an arrangement was too cheap, it is probably because it has been done poorly.
Basically, try to negotiate a guarantee for settlement made. For example, ask if in case your arrangement fails, if you need to pay back. It is useful to discuss this issue before to avoid any misunderstanding later. Finally, do not forget to ask for a written proof of the budget, it will serve you in case of complaint.
Experience: always ask the plumber how many years of experience he has. The more experience, the less risk. Also keep in mind the references of these and the qualifications.
Questions to ask: If you need to buy replacement material, find out where the plumber intends to buy it. Make sure the parts are quality and include a warranty. Also, you have to evaluate if you would not simply have to change the part, instead of repairing a pipe that is broken because it is already worn out, find out if it is cheaper for you to buy another one. Also, ask what you intend to do if there is collateral damage, if taken into account in the budget. Generally, good plumbers are insured against damages to third parties.
In short a good plumber is able to provide quality work and started at the right time and day. Quickly identify the problem (if it is not complex) and after the arrangements care about leaving everything clean. It does not request more money from the one set in the budget. If something goes wrong during the repair, fix it again for free.