McDonnell & Miller 21-30

The McDonnell & Miller 21-30 float is a dependable replacement part for 311200 boiler controls. Engineered to meet the exacting standards of McDonnell & Miller, this float helps maintain accurate water level sensing and reliable boiler operation.

Designed as a replacement part for boiler controls in compatible systems, this float supports consistent performance with model 311200 components. Built from corrosion-resistant, durable materials, it helps minimize downtime and extend the life of your boiler control assembly.

Optimize your boiler efficiency with the 21-30 float, a trusted choice for professional maintenance and service teams. It’s a cost-effective solution that helps prevent overfill and dry-fire situations, protecting your equipment and reducing service calls.

• Easy installation—simple replacement that fits standard 311200 configurations
• Durable construction—robust, corrosion-resistant materials for long service life
• Reliable water level sensing—helps maintain accurate boiler operation
• OEM-compatible—designed to match original McDonnell & Miller specifications
• Cost-effective maintenance—reduces downtime and service calls