Catchment Woes

[DaVinci]

That is interesting. Do you think it could happen the other way? Like, if the valve was faulty, could it leak when the water in that system gets cold? Because it seems like the extra cycles happen at night, or on heavily overcast days.

[Royall]

I would think that the reason it happens at night more is the fact the pump isn't run to build up as it would during the day. Just put a ladder up and inspect. Might even be able to see it if you get back far enough and use a binoculars... that is if you have a ones story home.

[dobanion]

As previously stated by others, always suspect the check valve first. I have had great success with the simple PVC deals, slip fit, glued into the line. I put mine after my pump, so my pump head "rests" at 0 pressure.

If you have a back flushing filter of some sort, check the outlet from that. I just discovered mine is leaking 20gal+ a day as soon as I removed it from drain to ground to drain to container. I was gonna water some plants with it.

Accumulator of some sort? It could be leaking AIR out the top at the shrader valve, which means pressure drops, pump cycles on. If this was the case, eventually it will stop being a very good accumulator.

Last, maybe just the pressure switch itself is getting lazy.

[terracore]

We had the same problem and the culprit was toilet flapper. We didn't notice it during the day because the suspect toilet was getting flushed regularly during the day and set off the pump when we would expect it and didn't drain down enough in between normal for the mystery pump run. But it was a toilet that rarely got used at night so that is when it drained enough water to cause the pump to run.

Because it wasn't a flush the toilet would almost be done filling by the time the pump started so we never "caught" the toilet running when the pump was.

Try turning the water supply off to the toilets at night and check them in the morning. The one with the empty tank is the culprit.