Arrived onsite for noise from the boiler with pipes shaking. Turned on thermostat and confirmed operation. Found the temperature gauge over high limit at about 20 degrees. Manually opened all zone valves. Checked return pipes on all 5 zones. Only felt heat on 3 of the five zones. Zone for back basement rooms and zone for the family room were not heating. System felt like there may be a water blocking or significant sludging inside the boiler section which could be trapping heat and causing the overheating. Observed two failed air vents. Recommend upgrading to spirovent to improve air elimination. Recommend adding two 1 inch isolation valves to the supply to isolate boiler and isolate expansion tank. Observed leaking 1/2 ball valve. Did not observe a back flow preventer to stop dirty boiler water from entering domestic drinking water supply. Homeowner would like to have an estimate to upgrade the boiler.
