Diagnosed boiler system experiencing insufficient circulation due to air-lock condition. Removed and replaced a section of 1" copper piping as requested by homeowner. Performed system purge to eliminate air entrapment, thawed a blocked baseboard loop restricting flow, and restored normal circulation. Established proper water pressure at 20 psi, verified burner operation and gas pressure. System returned to normal operation with supply and return lines heating correctly. Note: Third zone remains intentionally shut as homeowners are aware and currently remodeling that area.
