mcdonnell miller
McDonnell Miller, a trusted name in boiler controls and flow switches, offers a comprehensive collection of products designed for efficiency and reliability. Explore our selection and find the perfect fit for your needs.
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![Mcdonnell Miller 324100 Transformer 101-24V-48 Replacement for 101A Series 24 Volt | Midwest Supply Us](http://midwestsupplyus.com/cdn/shop/files/514897_dab945c5-874f-4b07-9580-fa7a583465fc_medium.jpg?v=1719942335)
324100 | Transformer 101-24V-48 Replacement for 101A Series 24 Volt | Mcdonnell Miller
Brand: Mcdonnell Miller
SKU: 324100
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![Mcdonnell Miller 317354 Vacuum Breaker TC-V for TC-4 Test-N-Check Valve | Midwest Supply Us](http://midwestsupplyus.com/cdn/shop/files/786106_9be075cf-072c-425a-98cc-b902584a956c_medium.jpg?v=1719942293)
317354 | Vacuum Breaker TC-V for TC-4 Test-N-Check Valve | Mcdonnell Miller
Brand: Mcdonnell Miller
SKU: 317354
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![Mcdonnell Miller 317350 Check Valve Upper Test Vacuum Breaker with Gasket Model TC-U | Midwest Supply Us](http://midwestsupplyus.com/cdn/shop/files/995203_d42a2a97-a685-4d2c-a60d-7d3d4c918119_medium.jpg?v=1719942323)
317350 | Check Valve Upper Test Vacuum Breaker with Gasket Model TC-U | Mcdonnell Miller
Brand: Mcdonnell Miller
SKU: 317350
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![Mcdonnell Miller 315450 Cap Dirt Pocket 47-171 for 47/247 Series | Midwest Supply Us](http://midwestsupplyus.com/cdn/shop/files/mcdonnell-and-miller_f0520f30-a410-44ba-930f-48873bd87b1d_medium.gif?v=1717080024)
315450 | Cap Dirt Pocket 47-171 for 47/247 Series | Mcdonnell Miller
Brand: Mcdonnell Miller
SKU: 315450
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![Mcdonnell Miller 310800 Gasket 21-12 for 21 Series for Boiler | Midwest Supply Us](http://midwestsupplyus.com/cdn/shop/files/55579_medium.jpg?v=1717080060)
310800 | Gasket 21-12 for 21 Series for Boiler | Mcdonnell Miller
Brand: Mcdonnell Miller
SKU: 310800
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![Mcdonnell Miller 310490 Control Unit 150E-CU with Auto Reset for Series 150E/157E | Midwest Supply Us](http://midwestsupplyus.com/cdn/shop/files/663402_medium.jpg?v=1719942301)
310490 | Control Unit 150E-CU with Auto Reset for Series 150E/157E | Mcdonnell Miller
Brand: Mcdonnell Miller
SKU: 310490
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![Mcdonnell Miller 310488 Switch Assembly Snap Action for 42S Model SWA42S | Midwest Supply Us](http://midwestsupplyus.com/cdn/shop/files/995131_dc9df841-bae8-408b-8df9-02826e8f7312_medium.jpg?v=1719942299)
310488 | Switch Assembly Snap Action for 42S Model SWA42S | Mcdonnell Miller
Brand: Mcdonnell Miller
SKU: 310488
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![Mcdonnell Miller 310473 Orifice Kit Strainer for WF2U and WFE Series | Midwest Supply Us](http://midwestsupplyus.com/cdn/shop/files/969518_9f19afdf-65f8-4eda-a3a4-71807339afdb_medium.jpg?v=1717080050)
310473 | Orifice Kit Strainer for WF2U and WFE Series | Mcdonnell Miller
Brand: Mcdonnell Miller
SKU: 310473
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![Mcdonnell Miller 310472 Valve Assembly Reverse Acting Model SWA-PFC-R | Midwest Supply Us](http://midwestsupplyus.com/cdn/shop/files/995243_medium.jpg?v=1717080039)
310472 | Valve Assembly Reverse Acting Model SWA-PFC-R | Mcdonnell Miller
Brand: Mcdonnell Miller
SKU: 310472
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![Mcdonnell Miller 310462 Switch SWA150S Snap Assembly Replacement | Midwest Supply Us](http://midwestsupplyus.com/cdn/shop/files/786105_medium.jpg?v=1717079976)
310462 | Switch SWA150S Snap Assembly Replacement | Mcdonnell Miller
Brand: Mcdonnell Miller
SKU: 310462
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![Mcdonnell Miller 310451 Paddle Assembly FS4-15 Stainless Steel | Midwest Supply Us](http://midwestsupplyus.com/cdn/shop/files/108733_medium.jpg?v=1717080027)
310451 | Paddle Assembly FS4-15 Stainless Steel | Mcdonnell Miller
Brand: Mcdonnell Miller
SKU: 310451
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![Mcdonnell Miller 310447 Blow Down Valve 14-B Ball Type for 47/247/67/70B Series 30 Pounds per Square Inch | Midwest Supply Us](http://midwestsupplyus.com/cdn/shop/files/12487_2a368312-8707-4e07-965e-fa2ce1b51e7b_medium.jpg?v=1719942289)
310447 | Blow Down Valve 14-B Ball Type for 47/247/67/70B Series 30 Pounds per Square Inch | Mcdonnell Miller
Brand: Mcdonnell Miller
SKU: 310447
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![Mcdonnell Miller 310442 Bracket Assembly for Series BA-551-05 Bellows | Midwest Supply Us](http://midwestsupplyus.com/cdn/shop/files/995254_medium.jpg?v=1717080002)
310442 | Bracket Assembly for Series BA-551-05 Bellows | Mcdonnell Miller
Brand: Mcdonnell Miller
SKU: 310442
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![Mcdonnell Miller 310439 Bracket Assembly for Series 51/52-2 Bellows Water Feeder BA-51-05 | Midwest Supply Us](http://midwestsupplyus.com/cdn/shop/files/969463_medium.jpg?v=1719942312)
310439 | Bracket Assembly for Series 51/52-2 Bellows Water Feeder BA-51-05 | Mcdonnell Miller
Brand: Mcdonnell Miller
SKU: 310439
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![Mcdonnell Miller 309200 Switch 11MV for 61/64/67/69/70/764/767 | Midwest Supply Us](http://midwestsupplyus.com/cdn/shop/files/12486_0ec9befd-060c-48e9-b668-bb1817d304c0_medium.jpg?v=1717080066)
309200 | Switch 11MV for 61/64/67/69/70/764/767 | Mcdonnell Miller
Brand: Mcdonnell Miller
SKU: 309200
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![Mcdonnell Miller 309100 Flow Switch 11 Replacement with Manual Reset | Midwest Supply Us](http://midwestsupplyus.com/cdn/shop/files/12485_eb1cd9ce-793c-4a11-9778-85647f7a0a87_medium.jpg?v=1719942332)
309100 | Flow Switch 11 Replacement with Manual Reset | Mcdonnell Miller
Brand: Mcdonnell Miller
SKU: 309100
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![Mcdonnell Miller 309000 Resistor Slide Kit Model 7B-1R for 7B Switch | Midwest Supply Us](http://midwestsupplyus.com/cdn/shop/files/mcdonnell-and-miller_370dacea-ef52-4ddc-8af4-7d5455d2cf80_medium.gif?v=1717079936)
309000 | Resistor Slide Kit Model 7B-1R for 7B Switch | Mcdonnell Miller
Brand: Mcdonnell Miller
SKU: 309000
Application
- 101A; 47; 247; 847 Water Feeders
- 25-A Series Make-Up Water Feeder
- 42 and 42S Series Low Water Cut-Offs/Pump Controller
- 51; 851 Water Feeder
- Boiler Control
- Commercial/Industrial Low or High Pressure Boilers
- Commercial/Industrial Low or High Pressure Steam Boilers
- Electronic for Hot Water and Steam Boiler
- Low Water Cut Offs Water Feeder
- Low Water Cut Offs; Steam Boilers
- Primary Low Water Fuel Cut Off Protection and Pump Control for Commercial and Industrial Steam Boiler
- Protection Against High Water Condition in Steam Boilers and Other Water Level Applications
- Residential/Commercial Boilers with Steaming Capacity
- Residential/Commercial Industrial Low and Medium Pressure Steam Boilers with Separate Water Column
- Residential/Commercial Low Pressure Steam Boiler
- Residential/Commercial/Industrial Boiler with Steaming Capacity
- Series 247 and 247-2 Combination Low Water Cut-Offs/Pump Controllers
- Series 63 Low Water Cut-Offs
- Series FS4-3 and FS8-W General Purpose Liquid Flow Switches
- Tanks and Hydronic Heating Systems
- Water Feeders
Collection
End Connection
Material
Part Number
Pressure
Product Type
- 150S-HD with Manual Reset and Maximum Differential
- 158-S-HD with Manual Reset
- 2 Level High Pressure
- 51-2HD for Mechanical Water Feeder with Number 2 Switch Low Water Cut Off
- 69 with 1-3/16IN Insertion Length
- 851-S Make-Up with Extended Float and Rod Assembly
- Air
- Assembly CTRD-101
- Assembly CTRD-51
- Assembly For RS Series
- Assembly G-3-SS
- Assembly for 93/193/194 Control
- Auto Reset
- Ball Type for 47/247/67/70B Series
- Basket SA101-38
- CO-106 Screw and Pin
- Cast Iron Sensor Chamber with Probes
- Combination Pump Controller
- Combo Low Water Cut Off with Auto Reset SPST
- Combo Low Water Cut Off with Float Manual Reset SPST/SPDT
- Combo Low Water Cut Off with Maximum Differential SPST SPDT
- Combo Low Water Cut Off with Number 5 Switch
- Combo Low Water Cut Off with Quick Hook Up Fitting SPST
- Cover 4 Hole for RS-1 BR-1 Remote Sensor
- Cover for VFS VFC Gasket-PFC Series
- Cutoff with Manual Reset
- Direct Acting Liquid Level 3-15PSI Output
- Dirt Pocket 47-171 for 47/247 Series
- Electric
- Electric Replacement
- Electronic Manual Reset Probe
- Electronic with Auto Reset
- Electronic with Burner Control Harness
- Electronic with Manual Reset
- FLT-51-05 for 51 Water Feeder
- FS4-15
- FS4-3S with SPDT Body Stainless Steel
- FS4-3T1-3 High Flow SPDT
- FS4-3T3-4 Low Flow SPDT
- FS7-4D with 2 SPDT
- FS7-4SE Stainless SPDT with NEMA 7-9 Enclosure
- Fitting Lower for 42A/47/64A/67 Series
- Fitting Upper for 47/64/42/42S Series
- Fitting for 67 Series
- Float Arm 21-109 Model
- Float Type
- Float Type 3-18IN Insertion
- Float Type Auto Reset Number 2 Switch
- Float Type Manual Reset Number 2 Switch
- Float Type with 1-3/4IN Insertion
- Float Type with 2-1/4IN Insertion Length
- Float for Pneumatic Actuated Series PFC
- For 150 Series Snap Switch
- For 21 Series
- For 61/64/67/69/70/764/767
- For 64 Series
- For 69+ Series Model SA69-104
- For Combo Low Water Cut Off/Pump Controller With Manual Reset
- For Float Type Combo Low Water Cut Off/Pump Controller with Manual Reset
- For Low Water Cut Off 63 Series
- For Low Water Cut Off 64 Series
- For Low Water Cut Off 750/750-MT-120/PS800/PS801/PS850/PS851 Series
- For Mechanical Water Feeder 51 Series
- For RB-24E-S
- For Series 21 Make-Up Water Feeders
- For Series 51/52-2 Bellows Water Feeder BA-51-05
- For Series 851-S Make-Up Water Feeders
- For Series BA-551-05 Bellows
- For TC-4 Test-N-Check Valve
- For Water Feeder 25-A Series
- General Purpose Liquid SPDT
- General Purpose SPDT
- General Purpose SPDT with NEMA-1 Enclosure
- General Purpose SPDT with NEMA-4 Enclosure
- Ground
- High Pressure Model PA-750-HP
- High Sensitivity Liquid SPDT
- High Sensitivity SPDT
- High Sensitivity Single Pole Double Throw
- Insert for Low Water Cut Off 67 Series
- Junction F/Series 150-150S Low Water Cut Off Pump Controller
- Kit Model FS7-4W
- Large Model SA47-4
- Less Quick Hook Up Fittings
- Less Switch Steam 93-HDLS
- Liquid
- Long Barrel
- Long EA-157L for Series 157S-RBP
- Low Water Cut Off Controller Less Switch
- Low Water Cut Off Float Type Snap Switch SPST/SPDT
- Low Water Cut Off Float with Maximum Differential SPST/SPDT
- Low Water Cut Off Less Quick Hook Up Fittings
- Low Water Cut Off Number 5 Switch with Water Column
- Low Water Cut Off Proportional 7B with Manual Reset
- Low Water Cut Off Snap Acting Switch
- Low Water Cut-off
- Lower Test Model TC-L
- Main Valve 2200-2300
- Make Up
- Make Up Proportional Feed Action
- Make-Up for Model 847
- Manual Reset
- Manual Reset with Barrel Probe
- Manual Reset with Short Probe
- Manual Reset with Standard Probe
- Mechanical
- Mechanical Dual Switch
- Mechanical Less Quick Hook Up Fittings
- Medium Velocity Single Pole Double Throw
- Model 250-1 1.437M BTU
- Model 260-1
- Model BA-53-05
- Paddle Kit with 1IN and 6IN Paddles
- Potentiometer Automatic Reset
- Probe Style Auto Reset
- Probe for 4 Level Remote Sensor Model RS-4-BR-1
- Quick Hook Up
- Quick Hook Up Auto Reset Float Style
- Quick Hook Up Lever Operated
- RS-1-LP Low Pressure Sensor
- Remote High
- Replacement For 101A Series
- Replacement Harness for RB-24E-L
- Replacement Remote
- Replacement for 42S
- Replacement for 67-G
- Replacement for 93/193 Series Combination Low Water Cut Off Pump Controller
- Replacement for B-24E-B
- Replacement for Low Water Cut Off
- Replacement for Mechanical Water Feeder
- Replacement for Model 63BM/63M Float Type Low Water Cut Off
- Replacement for Model 93/193 Low Water Cut Off
- Replacement with 7B Switch for 94/194 Series Control
- Replacement with Manual Reset
- Reverse Acting Liquid Level 3-15PSI Output
- Reverse Acting Model SWA-PFC-R
- SA150-106R Replacement
- SA150-11 for Series 150/157 with Gasket
- SA159-17
- SA21-6
- SA25-5
- SA25A-15 with Valve Disc
- SA25A-6
- SA27T-75 Diaphragm
- SA37-30
- SA47-104 Replacement
- SA51-9
- SA51-9R
- SA51S-6
- SA63-5
- SA67-2
- Short EA-157S for Series 157S-RBP
- Short PA-Rb-122
- Single Level Remote High Pressure
- Single Pole Double Throw
- Slide Kit Model 7B-1R for 7B Switch
- Snap Action for 150S/157S Model SWA150S-M
- Snap Action for 42S Model SWA42S
- Snap Action for Model SWA150S-MD
- Snap Assembly Replacement
- Snap Assembly for SW-FS250
- Snap FS7-31
- Spring Loaded
- Stainless Steel Body NEMA 4X Enclosure Single Pole Double Throw
- Strainer for WF2U and WFE Series
- Supply for Pneumatic Actuated G-PFC-S
- Switch Replacement
- Teflon Coated
- Test-N- Check
- Universal for Hot Water Boilers with Vent Damper
- Upper SA66-35
- Upper Test Vacuum Breaker with Gasket Model TC-U
- Water Feeder Make-Up for 551S-HD
- With 2 Single Pole Double Throw Switches
- With 4-1/8IN Insertion Length
- With Auto Reset
- With Barrel Probe
- With Blow Down Auto Reset
- With Burner Control Harness
- With Corrosion Coating Single Pole Double Throw
- With Extended Paddle/Arm Single Pole Double Throw
- With Extension Barrel Model PSE-802-24
- With Fitting
- With Float Block
- With Float Block 63B
- With Gasket Model SA53-6
- With Gasket Model SA64-30
- With Gasket SA-63-30
- With Low Water Cut Off #2 Switch
- With Low Water Cut Off #2 Switch Manual Reset
- With Low Water Cut-off Mechanical
- With Manual Reset
- With Manual Reset Quick Hook Up
- With Millivolt Switch Length 1-3/4IN Insertion Length
- With NEMA 7/9 Enclosure Single Pole Double Throw
- With Pump Controller 150S-B with Manual Reset
- With Pump Controller 157S SPDT with Water Column
- With Pump Controller 157S with Manual Reset SPDT
- With Pump Controller 157S-R SPDT with Alternate Tapings
- With Pump Controller 157S-RBP-MD SPDT with 2 Integral Conductance Probes
- With Pump Controller 157S-RL Float Type Combo SPST/SPDT Auto Reset
- With Pump Controller 193 with 7B Switch Steam
- With Pump Controller 193-A with 7B Switch Steam
- With Pump Controller 193-B with 7B Switch Steam
- With Pump Controller 194-A with 7B Switch
- With Pump Controller 94 with 5 Switch SPDT
- With Pump Controller Alternate Tapping
- With Pump Controller Glass Connector
- With Pump Controller Manual Reset
- With Pump Controller Model 93-7B SPDT
- With Pump Controller Model 93-M SPDT Steam
- With Pump Controller Series 7B Switch
- With Pump Controller and Float Block
- With Quick Hook Up Fittings
- With Remote Sensor RX2 Probe
- With Stainless Steel Body Single Pole Double Throw
- With Standard Probe
- With Strainer SA51-101-102
- With Vent Damper Harness Model RB-24E-A
Size
Temperature
Used on
- 101-A Series Electrical Water Feeder and 551-S Series Make-Up Water Feeder
- 21; 25-A and 221 Series Make-Up Water Feeder
- 25-A Series Make-Up Water Feeder
- 64A; 47; 47-2 Controls
- 750B-C3/750B-C4 Series
- Actuation Control
- Air Flow
- Boiler
- Boiler Receiver Tanks
- Commercial and Industrial Liquid Level Open Tank Applications
- Hot Water/Steam Boilers
- Liquid Flow
- Low Pressure Steam and Hot Water Boilers
- Low Pressure Steam/Hot Water Boilers
- MA-159/MA-259 Quick Hook-up Fitting
- Multilevel Control
- PS-800/850 Series
- PS-801-U-120/PS-802-U-24 Series
- RS Sensors
- Series 150E/157E
- Series 21 and 221 Make-Up Water Feeders
- Series 247; 247-2; 47 and 47-2 Combination Low Water Cut-Offs/Pump Controllers
- Series 25A
- Series 51-S and 51-S-2 Combination Mechanical Water Feeder/Low Water Cut-Offs and Series 851-S Make-Up Water Feeders
- Series 51; 851
- Series 61/64/67/69/70
- Series 61; 67; 69 and 767 Low Water Cut-Off
- Series 63 Low Water Cut-Offs and Series 47; 47-2; 247; 247-2; 51; 51-2; 51-S; 51-S-2; 53 and 53-2 Combination Mechanical Water Feeder/Low Water Cut-Offs
- Series 67 Low Water Cut-Offs
- Series 750B Remote Mount Control Modules
- Series 93; 193; 94 and 194 Combination Low Water Cut-Offs/Pump Controllers
- Steam Boilers
- Steam/Hot Water Boilers with Cold Water Feed
- Water Boiler
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