The answer to 'why is my boiler short cycling' is that there are several common causes, including issues with the thermostat, low water pressure, or a problem with the boiler itself. Short cycling occurs when the boiler turns on and off rapidly, rather than running for a full heating cycle.
Some common symptoms of short cycling include your home not reaching the desired temperature, high energy bills, and wear and tear on the boiler components. Causes can include a malfunctioning thermostat, low water levels, a problem with the pressure relief valve, or issues with the boiler's internal controls. In many cases, short cycling is a sign that professional HVAC service is needed to diagnose and repair the underlying issue.