Genuine Cummins Onan oil filter with built-in bypass valve for Emerald NHE, NHEL, Marquis NHM (gasoline & LP), CCK Mobile/RV, NH Power Drawer, NH RV, and NHL generator models. Confirm model and spec letter before ordering. 90-day limited warranty.
The Cummins Onan 122-0800 is the OEM-specified oil filter for the Emerald III NHE and NHEL, Marquis NHM (gasoline and LP), CCK Mobile/RV, NH Power Drawer, NH RV, and NHL generator series. It is the companion filter to the 122-0645 — covering the NHE-based generator families where the 122-0645 covers the BGE-based families.
A key feature of this Green Label oil filter is its built-in bypass valve. This valve allows oil to flow past the filter element during cold starts (when oil is thick and pressure is high) or if the filter becomes plugged. Many non-Green Label "will-fit" filters lack this valve — when those filters trap debris and restrict flow, oil pressure starvation can occur, leading to high oil pressures, failed gaskets, and potentially serious engine damage.
Tested and designed specifically for Cummins Onan RV generators — meets OEM specifications across NHE, NHM, NH, CCK, and related series
Allows oil to bypass the filter during cold starts or if the filter plugs — prevents oil pressure starvation and engine damage; often absent in will-fit substitutes
Covers all NHE spec letters, NHEL A–E, all NHM variants (gasoline and LP), CCK Mobile/RV, NH RV, NH Power Drawer, and NHL — confirm your specific model and spec
Most compatible models replace every 150 hours — refer to the compatibility table and your Operator's Manual for the correct interval for your specific unit
Cummins Onan specifically highlights the bypass valve as a critical differentiator in Green Label oil filters. When a non-bypass filter traps debris and becomes restrictive, oil pressure can build to dangerous levels — causing gasket failures and potential engine damage on generators that may be running for hours at a time without monitoring. The bypass valve ensures continuous oil flow under two conditions: cold starts (when cold oil is thick and high-pressure) and filter saturation (when a clogged filter would otherwise starve the engine of oil). Always use a genuine Green Label filter to maintain this protection.
This filter covers a wide range of older Onan generator series. Always confirm using your generator's complete model code and spec letter — refer to the compatibility table below. Note: If your generator is a BGE-based model (Emerald I BGE/BGEL, Marquis BGM, or older BFA/BGA/BGAL), use oil filter 122-0645 instead. The 122-0800 covers the NHE-based generator families.
Backed by a 90-day limited manufacturer's warranty. Cummins Power Generation warrants only the quality and integrity of Green Label Parts. Damage caused by the use of non-Green Label oil filters — including damage from lack of bypass valve protection — is not covered under the Cummins Onan limited warranty.
Always confirm fitment using your generator's complete model code and spec letter. For BGE-based generators (Emerald I BGE/BGEL, Marquis BGM, BFA/BGA/BGAL), use oil filter 122-0645 instead. Refer to your Cummins Onan Operator's Manual for the correct oil change interval for your specific unit.