Key maintenance tasks for a commercial water heater include regular inspection of the heating elements, checking for leaks in the tank and connections, flushing the tank to remove sediment buildup, testing the pressure relief valve, and ensuring proper ventilation for gas-powered units. Regular maintenance helps to ensure longevity and efficiency of the water heater.

To prevent future clogs in your sewer drain after it has been cleared, you can consider the following measures:<br /><br />1. Avoid flushing non-biodegradable items down the toilet.<br />2. Use a hair catcher in the shower and bathtub drains to prevent hair buildup.<br />3. Dispose of cooking grease and oil in a proper container instead of pouring it down the drain.<br />4. Regularly clean out debris from drain strainers and stoppers.<br />5. Consider scheduling regular professional drain cleaning maintenance to prevent buildup.

The most common issues that can arise with bathroom plumbing include clogged drains, leaky faucets, running toilets, and low water pressure.

Some signs that indicate a clogged drain may be causing more serious issues within your plumbing system include multiple drains backing up simultaneously, gurgling noises coming from drains, foul odors emanating from drains, slow drainage in multiple fixtures, and water pooling around drains.

I would need more information about the issue with your water heater in order to provide an accurate estimate for the repair.