Followup - Electronic water meter: Can you turn on the faucet on Shabbos?
I posted a few days ago about electronic water meters and can they be used on Shabbos.
A number of people suggested that this should be permitted because it is a פסיק רישיה דלא ניחא ליה on an איסור דרבנן. I would like to raise 2 issues with that premise:
1. Is this really לא ניחא ליה? Everyone would agree that you cannot disconnect the meter before shabbos and use the water because you would be stealing from the water company. Therefore, the meter recording how much water you used is ניחא ליה. If the meter didn't record your use the company would not be able to charge you and you wouldn't know how much to pay, in essence you would be stealing. Therefore, you want the meter to record your use to keep you from stealing.
2. It is not so clear that פסיק רישיה דלא ניחא ליה on an איסור דרבנן is permitted. R' Eider in his sefer on hilchos shabbos writes that a פסיק רישיה דלא ניחא ליה on an איסור דרבנן is assur. The Shemiras Shabbos in the new edition has an introduction to Hilchos Shabbos. In the text he doesn't discuss פסיק רישיה דלא ניחא ליה on an איסור דרבנן but in a footnote he quotes a number of Mishna Berura's that it is assur. R' Willig in his sefer Am Mordechai on Shabbos, wanted to make the following distinction by פסיק רישיה דלא ניחא ליה on an איסור דרבנן. He said that if the issur is עיקרו מן התורה and it is only דרבנן for a technicality (מלאכה שאין צריכה לגופה ,מקלקל, etc.) then פסיק רישיה דלא ניחא ליה on an איסור דרבנן would be assur. But if the issur is עיקרו מדרבנן like electricity then פסיק רישיה דלא ניחא ליה would be mutar.