Rheem Marathon Water Heater Problems. If dirty, let it down for cooling and then clean. You’ll need to have a plumber increase your hot water flow rate to a minimum of two to three litres per minute.
Other gas water heater problems need to be serviced by a qualified service technician. Few water heaters can compete with the marathon. If you experience a leaking water heater, it is recommended to turn off the water to your tank.