Description
The McDonnell & Miller 47-2-M (Part Number 132900) is a heavy-duty mechanical water feeder engineered for reliable, automatic water level management in both steam and hot water boiler systems. Manufactured by Xylem under the trusted McDonnell & Miller brand, this combination unit integrates a cold water feed function and a low water cut-off in a single, compact assembly — reducing installation complexity and the number of components required on the boiler.
Key Features
- Combination mechanical water feeder and low water cut-off in one unit
- Quick hook-up fittings for fast, simplified installation on steam and hot water boilers
- Cold water feed function automatically maintains proper water level
- Low water cut-off protection shuts down burner when water drops below safe operating level
- Two snap-acting, manual reset SPDT (Single-Pole Double-Throw) switches for reliable electrical control
- Manual reset design requires deliberate operator action before restart, enhancing system safety
- Compatible with steam boilers and hot water boilers
Combination Functionality
The 47-2-M eliminates the need for separate feeder and cut-off devices. When the boiler water level drops, the mechanical float mechanism first activates the cold water feed to restore proper level. If the water level continues to fall to a critical low point, the two snap-acting SPDT switches interrupt the burner circuit, preventing dry-fire damage and potential system failure. The manual reset requirement ensures that an operator inspects the system before resuming normal operation — a critical safety feature for commercial and residential boiler installations.
Quick Hook-Up Fittings
The integrated quick hook-up fittings streamline the installation process, allowing technicians to connect the unit to the boiler’s water column tappings quickly and securely. This design reduces labor time and minimizes the risk of connection errors during installation or replacement.
Dual SPDT Switch Configuration
- Two independent snap-acting SPDT switches provide redundant circuit control
- Manual reset on both switches ensures deliberate operator intervention after a low-water event
- Snap-acting mechanism delivers fast, positive switching action for dependable burner shut-off
Applications
- Residential and light commercial steam boiler systems
- Hot water (hydronic) boiler systems
- Replacement or upgrade of existing water feeder and low water cut-off devices
- New boiler installations requiring combination feed and cut-off protection
Product Details
- Brand: McDonnell & Miller (Xylem)
- Model: 47-2-M
- Part Number: 132900
- Switch Type: Snap-Acting Manual Reset SPDT (x2)
- Function: Mechanical Water Feeder with Low Water Cut-Off
- Compatible Systems: Steam and Hot Water Boilers
- Fitting Style: Quick Hook-Up
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