Tankless water heater repair costs can vary depending on the issue and the extent of the repair required. One of the most common maintenance tasks for tankless water heaters is a routine flush and descaling, which typically costs between $150 and $350. This process involves flushing out any sediment buildup and removing mineral deposits that can accumulate over time, ensuring efficient and reliable operation.
In addition to routine maintenance, other common repairs for tankless water heaters may include replacing faulty components such as the ignition assembly, gas valve, or control board. These repairs can range from $200 to $800 or more, depending on the specific part and labor costs. If the entire unit needs to be replaced, the cost to install a tankless water heater can range from $1,400 to $5,600.