Uneven heating can come from a blocked register or return, a dirty filter, leaky or poorly insulated ducts, drafts, or insulation gaps. Sun exposure and room layout also affect how warm each space feels. Start by checking that furniture is not blocking vents and that the filter is clean.
If one room stays cold or the temperature gap is growing, a technician can check airflow and the heating system rather than guessing at a new thermostat setting. Stanley can evaluate the issue through its heating services.