99042-2 AERCO Boiler and Water Heater Dual Element Thermocouple Normal Stocking Item in Our Warehouse AERCO 99042‑2 is the OEM Dual‑Element Thermocouple Assembly used in AERCO boilers and water heaters. This part provides redundant, high‑accuracy temperature sensing for critical combustion and hydronic control functions. AERCO 99042‑2 Dual‑Element Thermocouple — OEM dual‑sensor temperature probe for AERCO boilers and water heaters. Provides redundant, high‑accuracy temperature feedback for combustion safety, modulation control, and hydronic system protection. Engineered for high‑temperature reliability and direct‑fit replacement in AERCO assemblies. Below is the complete, grounded, technician‑ready profile. 🔧 Core Identity & Function Part Number: 99042‑2 Component: Dual‑Element Thermocouple OEM: AERCO This sensor contains two thermocouple elements in one assembly, giving the controller two independent temperature signals for: Combustion safety monitoring Temperature‑limit protection Burner modulation feedback Redundant sensing for fault‑tolerant operation Dual‑element thermocouples are used in AERCO systems where precision and safety redundancy are required. 📐 Technical Characteristics While individual listings vary, grounded distributor data for AERCO dual‑element thermocouples confirms: Sensor Type: Dual thermocouple Construction: High‑temperature stainless probe Output: Millivolt signal proportional to temperature Use Case: High‑efficiency boilers & water heaters Mounting: Threaded or compression‑fit depending on model variant This part is functionally similar to AERCO 61056 (dual thermocouple), but 99042‑2 is used on different AERCO platforms and assemblies. Applications Used in: AERCO commercial boilers AERCO commercial water heaters Combustion chambers requiring redundant temperature feedback Safety‑limit and modulation circuits Typical replacement scenarios: Temperature drift Intermittent or unstable readings Control‑system lockouts Preventive maintenance