Keep your pellet stove running safely and reliably with this direct-replacement vacuum switch from Enviro. Designed to fit a specific range of Enviro and Vista Flame pellet stove models, this switch monitors combustion airflow and shuts down the stove if proper draft is not maintained -- a critical safety function. Also catalogued as NBK Parts 20261.
The Enviro 50-1390 vacuum switch is a factory-matched replacement component built to restore proper operation to pellet stoves that have lost combustion airflow sensing. When the vacuum switch fails, the stove may shut down unexpectedly, refuse to start, or run without proper draft safety monitoring. Replacing it with the correct OEM-specified part restores normal control board communication and safe operation.
This switch is sold individually and weighs 0.5 lbs. It is also cross-listed under the NBK Parts number 20261, making it straightforward to verify compatibility across multiple parts catalogs.
Engineered to the same specification as the original switch installed at the factory. No modification or adapters required for listed models.
Monitors combustion chamber vacuum (draft) and signals the control board to shut down the stove if airflow drops below a safe threshold.
Fits nine Enviro pellet stove models and two Vista Flame models, covering a wide range of residential insert and freestanding units.
Listed as both Enviro 50-1390 and NBK Parts 20261, making it easy to confirm you have the right part before ordering.
In a pellet stove, the vacuum switch (also called a differential pressure switch or draft inducer switch) is wired into the control board circuit. It verifies that the combustion blower is creating adequate negative pressure inside the combustion chamber before and during a burn cycle. If the exhaust path is blocked, the blower fails, or a hose connection leaks, the switch opens the circuit and the stove shuts down safely rather than continuing to run without proper venting.
A failed vacuum switch -- one that is stuck open or stuck closed -- will cause the stove either to refuse to light or to run without proper draft monitoring. Replacement with the correct part number restores accurate pressure sensing.
The vacuum switch is typically located inside the stove cabinet, mounted near the combustion blower or on a bracket along the control board housing. Access requires removing the stove's side or rear panel per your model's service procedure. The switch connects via two spade-terminal wires and one or two small rubber vacuum hoses. No special tools are required beyond a basic screwdriver set.