Why is your heater hot on one side cold on other?

A heater can be hot on one side and cold on the other due to uneven heat distribution, often caused by air pockets or trapped air in the system. If the heater is not properly bled, air can accumulate, preventing hot water from circulating evenly. Additionally, issues with the heating element or a malfunctioning thermostat can also lead to this temperature discrepancy. Regular maintenance and bleeding the system can help resolve this issue.