Best Of

I agree with replacing the #67 and the #47 LWCO at certain intervals, As long as they have been flushed properly each week. If it has been neglected for a few years, then I would NOT spend the time cleaning it out. Mostly because my labor to do it properly would cost too much, compared to replacing it and having a 10 year old rebuilt part when completed. But I would take one apart and do a deep cleaning and install new gaskets and flush valve every 5 years or so. Then make a judgment call as to the need for a new replacement or keel the existing.

I have been looking for a story or video that has a #67 that would appear to operate properly on a flush (because the fast flow of the water past the float forced the switch off) but failed to shut off the burner when the water level dropped slowly as it might during normal operation.
That was because there was a small mound of build up on the ledge that the float would get stuck on, and that flushing failed to remove. I believe it was @DanHolohan who published it but I just can't find it. I stole this pic from Gordo to illustrate how the fast moving water in the flush didn’t move all the schmutz outta the way. (schmutz is a technical term)

Probably because the flush was not done with high enough steam pressure