You need to knowing when you should hire a plumber so that you don’t waste money. The right time to hire a plumber is when the problem is big, and when there’s a higher risk of doing more damage than good.
You need a plumber when:

• You have a drop in water pressure throughout the house: This problem can be caused by: obstructions (rust or debris) in the water lines; low water pressure from the main city supply or a well; or even poor supply-line design.
• You have no running hot water: Unless the hot water system tank is leaking, it might be hard to determine the cause. Examples of hot water system problems include: heating elements, circuit breakers or blown fuses, faulty thermostats, or a bad overload switch. Gas hot water heater problems might be: thermocouple burners and igniters.
• Replacing a hot water heater is a big job. Be sure you know what you are doing if you are going to attempt to replace the system by your self.
• If you cannot unblock the sewer line, you probably have a bad plug in the line that runs out to the main sewer, which is often tree roots. You will need to call a professional plumber or drain-cleaning service. If the plumber gets in trouble, they will know what repairs to make.
• You might have extensive water line damage: Repairing water line damage, which is usually caused by freezing, can take many hours