The Enviro EF-017 (part number 20165, also listed as NBK Parts 20165) is a genuine replacement vacuum switch engineered for a wide range of Enviro and Hudson River pellet stove models. If your stove is faulting, failing to ignite, or shutting down unexpectedly, a failed vacuum switch is one of the most common culprits -- this is the correct OEM-spec replacement to restore normal operation.
The vacuum switch is a critical safety and operational component in pellet stoves. It monitors negative pressure created by the combustion blower to confirm that the exhaust system is functioning properly. If the switch does not detect adequate draft -- due to a clogged exhaust, a failed blower, or a faulty switch itself -- it will interrupt the burn cycle to prevent unsafe operation.
When the switch itself wears out or fails, the stove may display a fault code, refuse to light, or shut down shortly after startup even when the exhaust and blower are in good condition. Replacing the vacuum switch with the correct OEM part is a straightforward fix that restores normal stove function.
Genuine Enviro part EF-017 (20165). Built to the same specification as the original factory-installed switch.
Fits 12 Enviro models and 4 Hudson River models -- one of the most commonly used vacuum switches in the Enviro pellet stove lineup.
Designed for standard North American 115V pellet stove electrical systems. Verify your stove voltage before ordering.
Weighs just 0.3 lbs. Easy to handle and install in tight firebox and control panel spaces.
During startup, the combustion blower spins up and creates a negative pressure (vacuum) in the exhaust system. The vacuum switch detects this pressure differential through a small port or tubing connected to the exhaust pathway. Once sufficient vacuum is confirmed, the switch closes and allows the ignition and feed cycles to proceed. If the switch never closes -- or opens during operation -- the control board halts the burn cycle as a safety precaution.
Before ordering, confirm the vacuum switch is actually the failed component. A quick diagnostic check with a multimeter and a known good vacuum source (or a simple breath test on the port) can confirm whether the switch opens and closes at the correct pressure differential. Also inspect the small rubber tubing that connects the switch to the exhaust port -- cracks or disconnected tubing can mimic a switch failure without actually requiring a new switch.
The EF-017 vacuum switch is typically mounted on the interior chassis of the stove near the combustion blower or exhaust pathway. Installation involves disconnecting the wiring harness connector and the vacuum tubing, unbolting the old switch, and reversing the process with the new unit. No special tools are required beyond basic hand tools. Always power down and unplug the stove before beginning any service work.