or if you see a diagnostic code indicating a pressure switch circuit error

High-performance water heater maintenance requires the Lochinvar & A

For larger Knight XL or Crest series

Key Benefits for Technicians OEM Compatibility: Precision-fit for Heil

Robust Construction: Built to withstand high-pressure spikes and thermal cycling common in legacy R22 hardware

Resideo PV075S Eliminator 321042-401 or if you see aThe Resideo PV075S Eliminator is a high performance 3 4 inch sweat power vent designed for critical air management in hydronic heating systems. Engineered for efficient microbubble removal, this unit utilizes an internal stainless steel concentric coalescing medium to break surface tension and release trapped air from the system fluid. By maintaining a deaerated system, the PV075S prevents oxygen related corrosion and ensures optimal heat transfer