McDonnell & Miller 304100 Head Gasket

The McDonnell & Miller 304100 Head Gasket (Model F-26) is a critical sealing component engineered specifically for high-performance boiler water feeders and low water cut-off systems. As a veteran-grade replacement part, this F-26 head gasket is designed to provide a high-integrity, leak-proof seal between the water feeder body and the head mechanism, ensuring system pressure remains constant and prevents intermittent dry-firing or boiler scale accumulation around the flange. This OEM-spec M&M 304100 is fully compatible with the McDonnell & Miller Series 221, 25A, 51, 51-2, 53, and 3155 water feeders. Whether you are performing a mid-season teardown or a standard maintenance overhaul, utilizing a genuine boiler gasket replacement is essential for maintaining the factory-calibrated buoyancy and mechanical response of the float assembly. Its precise thickness and material composition are optimized for the thermal cycling and chemical environments common in hydronic heating systems and commercial steam applications, preventing premature material degradation and maintaining the safety interface of your water level control.

• Multi-Series Compatibility: Engineered for seamless fitment in Series 221, 25-A, 51, 51-S, 53, and 3155 water feeders.
• Operational Reliability: Ensures a hermetic seal to prevent vacuum leaks and external weeping in low water cut-off units.
• Durable Construction: High-grade gasket material resists compression set and thermal expansion common in high-pressure boiler environments.
• Direct OEM Replacement: Standard McDonnell & Miller F-26 dimensions ensure no field-modifications are required during service.

Which water feeder series is the McDonnell & Miller 304100 compatible with?
This head gasket is specifically designed for use with McDonnell & Miller Series 221, 25A, 51, 51-2, 51-S, 51-S-2, 53, 53-2, 551-S, and 3155 units.

How do I tell if my F-26 head gasket requires replacement?
If you notice moisture or mineral deposits around the seam where the head meets the body, or if the water feeder is exhibiting sluggish mechanical response due to internal pressure variations, a seal inspection is recommended.

Is the 304100 the same as the F-26 model?
Yes, 304100 is the official manufacturer part number (MPN) for the Model F-26 gasket used across several legacy and modern M&M water feeders.

Disclaimer: While we strive for 100% accuracy, product data and specifications are subject to change. Please contact our team to confirm compatibility or technical details before purchasing.