What are the common causes of fluctuations in water heater pressure and how can they be resolved effectively?

Common causes of fluctuations in water heater pressure include mineral buildup in the pipes, a faulty pressure relief valve, or a malfunctioning water heater. To resolve these issues effectively, you can try flushing the water heater to remove mineral buildup, replacing the pressure relief valve, or repairing or replacing the water heater if necessary. It is recommended to consult a professional plumber for proper diagnosis and repair.