Today I arrived on site to address a no-heat situation affecting the heating and DHW systems. Diagnosis:Found the LWCO (Low Water Cut-Off) tripped. Identified the water sensor as disconnected and leaking. Noted the APS (Air Pressure Switch) was also disconnected. Resolution:[No resolution provided] Upon arriving at the property, the client explained to me that the system has been checked by several technicians. The client directed me to where the boiler unit is. This is a high efficiency water boiler (K2). I did a visual inspection of the system. I found some water leaks inside and outside the system. I showed the client where the water leaks come from. I also found several components of the unit disconnected. I showed the customer the disconnected components inside the unit. I found the igniter and the flame sensor in mama condition. I proceeded to connect the APS. I proceeded to connect the water temperature sensor. I also found the LWCO Tripped. Reset the LWCO device.