MM 150 SHD

William Faust

My boiler's manual says that my MM 150S LWCO cast line should be 2-3/8" above the bottom of the gauge glass. The actual figure is 1-1/16". My backup MM 61 LWCO cast line should be 1/2" above the bottom of the gauge, but it is actually right at the bottom. Are these issues that should be rectified?

bob young

inline piping

does not the inline field fabricated piping determine the cut off point of these controls. what size is this unit ?

William Faust

cast line

If by unit you mean the boiler, it is a 15.7 HP Weil McLain LGB-6. The boiler manual indicates using a 2" long nipple below the MM 150S LWCO (not furnished by WM) and what is actually there indeed appears to be 2" long. The cast line is nonetheless 11/16" too low relative to WM's installation instructions. This 11/16" difference may amount to the installing contractor using too much thread at both ends of the nipple. In any event, is this difference an issue?

In the case of the MM 61 backup LWCO, the cast line is AT the bottom of the gauge glass rather than at 1/2" above the bottom as per WM installation instructions. In this instance also, it may be that the contractor used too much thread and thereby missed the 1/2" target. Is this an issue?

bob young

150

from what you are saying ,it seems to be within safe parameters but lets hear if the other experts concur.

oil-2-4-6-gas

the cast mark on the low wates are not always absolute ---you need to fill it and dynamically test it /// a lot of time people will measure -from the floor to the cast line -well if the floor and control are --level this is fine --but (90% of the time they ar not ) if the piping is not plumb and level ---or any of the tappings are off (again 90% of the time they are) --NOW if they trully are too low --for protection -they can and ae adjusted by shortening and lengthening nipples -( if it was installed with unions above and below --this is an easy process) Oh yeah the "S" model is the snap acting switches as oppose to the mercury switches --the mercury switches can be adjustedwhereas the snap acing switches are ---Not supposed to be adjustable --But i have done it -in a pinch ----HOW OLD IS this insall?

William Faust

The install was in 1997 or 1998.

oil-2-4-6-gas

you can have someone come in and check,and make any necessary adjutments