Head Mechanisms

McDonnell & Miller model number 42S-HD is a head mechanism for model number 42-S controls. Head mechanisms include everything except a float chamber. They allow for quick and easy replacement by removing the bolts on the float chamber and then removing and replacing the new unit, with no need to disrupt piping. Learn More

McDonnell & Miller model number 64-HD is a head mechanism for model number 64 and 764 controls. Head mechanisms include everything except a float chamber. They allow for quick and easy replacement by removing the bolts on the float chamber and then removing and replacing the new unit, with no need to disrupt piping. Learn More

McDonnell & Miller model number 93-HD is a head mechanism, with standard number 5 switch, for model number 93 and 193 controls. Head mechanisms include everything except a float chamber. They allow for quick and easy replacement by removing the bolts on the float chamber and then removing and replacing the new unit, with no need to disrupt piping. Learn More

McDonnell & Miller model number 93-7B-HD is a head mechanism, with standard number 7B switch, for model number 93 and 193 controls. Head mechanisms include everything except a float chamber. They allow for quick and easy replacement by removing the bolts on the float chamber and then removing and replacing the new unit, with no need to disrupt piping. Learn More

McDonnell & Miller model 93-HDLS head mechanism less switch. Learn More

McDonnell & Miller model number 94-HD is a head mechanism, with standard number 5 switch, for model number 94 and 194 controls. Head mechanisms include everything except a float chamber. They allow for quick and easy replacement by removing the bolts on the float chamber and then removing and replacing the new unit, with no need to disrupt piping. Learn More

McDonnell & Miller model number 94-HDLS is a head mechanism, without standard number 5 switch, for model number 94 and 194 controls. Head mechanisms include everything except a float chamber. They allow for quick and easy replacement by removing the bolts on the float chamber and then removing and replacing the new unit, with no need to disrupt piping. Learn More

McDonnell & Miller model number 94-7B-HD is a head mechanism, with standard number 7B switch, for model number 94 and 194 controls. Head mechanisms include everything except a float chamber. They allow for quick and easy replacement by removing the bolts on the float chamber and then removing and replacing the new unit, with no need to disrupt piping. Learn More

McDonnell & Miller 173003 replacement head mechanism 150S-HD with automatic snap-action switch assembly repairs Series 150, 150S & Series 157, 157S combination low water cut-off, pump controllers for steam boilers. Learn More

McDonnell & Miller 150S-M-HD Head Mechanism Manual Reset 172809 for 150S-M Low Water Cut-Off/Pump Controller Learn More

McDonnell & Miller model number 150S-MD-HD is a head mechanism for model number 150S-MD and 157S-MD controls. Head mechanisms include everything except a float chamber. They allow for quick and easy replacement by removing the bolts on the float chamber and then removing and replacing the new unit, with no need to disrupt piping. Learn More

McDonnell & Miller model number 150S-M-MD-HD is a head mechanism for model number 150S-MD and 157S-MD controls. Head mechanisms include everything except a float chamber. They allow for quick and easy replacement by removing the bolts on the float chamber and then removing and replacing the new unit, with no need to disrupt piping. Learn More

McDonnell & Miller model number 159S-HD is a head mechanism for model number 159S controls. Head mechanisms include everything except a float chamber. They allow for quick and easy replacement by removing the bolts on the float chamber and then removing and replacing the new unit, with no need to disrupt piping. Learn More

McDonnell & Miller replacement head mechanism with manual reset for Model 94-M combination low water cut-off/pump controllers. Learn More

McDonnell & Miller combination low water cut off and pump controller head mechanism with two snap-acting manual reset and SPDT switch for steam boilers with 150 psi max pressure. Learn More

McDonnell & Miller model number 64M-HD is a head mechanism for use with model E-11M-24V (SKU: MI1615) or model E-11M-120V (SKU: MI1616) reset switches. Learn More