Today I arrived on site to address the heating issue. Heating & DHW Systems Service: Identified multiple failing parts in both the Boiler and AHU systems. Determined parts replacement is necessary to resolve the heating malfunction. Upon arrival at the property. The client directed me to the equipment room. The customer explained that the heat is not working. I proceeded to verify the system. I found the boiler unit displaying a lockout alarm ARHL & MRHL. Indicating ignition failure, and high limit sensor failure. I also checked the AHU. I found the AHU control board not working properly. I also checked the tstat. The tstat also has communication failures with the AHU. I showed him and explained to the client that it is necessary to consider replacing the following parts so that the system works normally again. Necessary parts: Boiler unit. -Control board. -High Limit Sensor. -Ignition / flame sensor assembly. ————— AHU: -Control board. -Thermostat.(T4) Office to foll