All in all, you should expect your 24-hour plumber to be able to do the most basic of plumbing services which would be fixing your drainage, sewerage or water system. They should also be able to run some form of diagnostic to ensure that what they see is actually the problem as well as be able to identify whether trouble is brewing in your system. They should also be able to run some form of diagnostic to ensure that what they see is actually the problem as well as be able to identify whether trouble is brewing in your system. Some plumbing work might require the use of their hands alone so you shouldnt be alarmed if your plumber does not have some form of mechanical machinery. Sometimes they will come with machines to help make the work smooth or for example identify whether there are any faults in your piping
Another way you can be able to vet a company is to ask around if the major construction players have heard about them. Plumbing and construction companies work closely together. You can ask your contractor which company is best for any issues that might arise with your plumbing. If you are lucky enough to have a contractor who has an established rapport with a plumbing company, ask them if the services offered are 24/7. Your contractor or the person who was in charge of your construction project should be in a better position to give you tips or even refer you to the plumber they used.