There is no universal answer to this question since plumbers may charge different rates for flushing a water heater. However, the average cost for this service is usually around $50-$75. Before calling a plumber, it's important to determine whether or not the problem is caused by sediment buildup. If the water heater is only 2-3 years old and has never been flushed before, there's a good chance that the issue can be resolved by simply flushing it yourself. Instructions on how to do this can usually be found online or in the manual that came with your water heater.

It depends on a few factors, such as the plumber's experience, the severity of the clog, and whether or not any replacement parts are needed. Generally speaking, though, you can expect to pay anywhere from $75 to $150 for a water heater flush.