Okay to adjust control head screws?

William Faust

My gauge glass is 9-1/4" tall. The water level in the gauge is normally 3-1/2" from the bottom rather than at the half-way mark (4-6/8"). Is this a problem?

In considering this issue, I looked inside the controller head of my 150S LWCO and I was able to determine which of the two switches actuates the boiler feeder. It appears that one could raise the float level in the LWCO at which the controller would actuate the boiler feeder by simply adjusting a screw on the switch. Is this the right approach?

bob young

be careful

before you start adjusting a sensitive , expensive ,critical safety control , which you know nothing about, maybe you should at least read the factory literature explaining this product. kinda like taking a watch apart to see if you can make it work differently.

William Faust

don't break the watch

Your point is well taken and that's why I'm asking. Let me first redirect my question toward a better description of my problem. As I mentioned, my boiler's gauge glass normally shows a water level at 3-1/2" above the bottom of the gauge whereas I thought that it should be at the mid-point of 4-5/8". Let me know if this is a non-issue for system performance. On the chance that it is, I made an assumption that this condition could be related to the function of the boiler feeder controller.

In answer to your question, I have read the MM 150S manual and noted the chart that indicates approx. distances above cast line for pump on/off and burner on/off functions. That's why I made the other post, to which you also responded and for which I thank you, concerning the fact that my cast lines are not quite where they are supposed to be located relative to the bottom of the gauge glass. Additionally, I noted that the MM online document 150s-157.pdf addressed controller head or snap switch assemmbly replacement by saying that, "We recommend complete head replacement to eliminate the need for field adjustment of the switch assembly." That statement is what precipitated my question concerning whether adjusting the switch that controls the boiler feeder - the relevant switch and the screw on the switch being obvious - would be appropriate for an effort to raise the boiler's operating water level. A knucklhead installed this boiler and did just about everything wrong and I would not have put it past him to have turned that screw and fouled up what otherwise might have been an appropriate factory adjustment that would have resulted in a proper level of boiler operating water.

As I've said, however, if the indicated water level is a non-issue, this is all much ado about nothing.

bob young

periodic inspection

how old is the boiler & when is the last time it was inspected by a qualified registered tradesman. a sophisticated system such as this warrants yearly inspections. in new york city it is the law. protect your investment at all times.

William Faust

her age

Installed in early 1998 for a 2-pipe gravity steam system dated from May 1946, the boiler is a Weil-McLain LGB-6 (sized for the radiation) that is now pumped.

In answer to your question, the knucklehead who installed it for our home's prior owner was inspecting it, but it's become apparent that they didn't know anything. We believe that we have secured a steam system-competent contractor, but not necessarily one who is soup-to-nuts like a Steamhead or Pompetti.