Replacement Parts List

18
Boiler Control Replacement Parts
McDonnell & Miller
B
OILER
C
ONTROLS
Series 42 and 42S
Low Water Cut-Off/Pump Controllers
Combination Low Water Cut-Off/Pump Controllers
For Steam Boilers
Model 42S-HD
For Repl. Head Part Weight
Model Model No. Number Description lbs. (kg)
42S 42S-HD 129502 Head mechanism 7.5 (3.4)
Series 42S
Model 42S-A
Components (shown on page 19)
Item Part Model Weight
Number Number Number Description lbs. (kg)
1 302600 CO-12 Head gasket 0.1 (.05)
2* 328300 MA-159 Quick hook-up fittings 6.0 (2.7)
(includes items 4, 5, 6)
3* 351800 SA259-24 Upper quick hook-up fittings 1.7 (.77)
4* 349500 SA159-24 Lower quick hook-up fittings 1.7 (.77)
5* 349400 SA159-17 Black “Y” assembly 3.0 (1.4)
6 347900 SA150-106R Bellows Assembly 0.4 (.18)
Replacement Head Mechanisms
Head mechanisms include a gasket and bolts.
* Available for 42S-A models only.
IMPORTANT:
• Snap switches must be replaced as an assembly.
• We recommend complete head replacement to eliminate the
need for field replacement of the switch assembly.
• Series 42 & 42S Replacement Switch Assemblies are not inter-
changeable and must be selected and ordered for the specific
control model(s) on which they will be installed.
Replacement Switch Assemblies For Series 42S
Model SWA-42S
For Repl. Switch Part Weight
Model Model No. Number Description lbs. (kg)
42S SWA-42S 310488 Snap-action 0.5 (.23)
switch assembly
Replacement Switch Information