Having a garage built. They were digging with a backhoe in the area of the Rehau pipes that were trenched from the vertical wells to the house. Although the backhoe didn't catch the pipe, hand digging in the area uncovered the pipes at a depth of 40 inches. Contractor told me and I checked the pressure at the p/t ports and it was 82 psi. Several hours later, it was 79 psi. System was not running either time I checked. Could it easily vary several psi over the day as the system runs intermittently and the weather here is warming? Or could there be a slight leak now? I will check the pressure again a few times before the concrete is poured tomorrow.

Yes, pressure changes with temperature. On the other hand, if it keeps dropping....

I've seen and am used to slight variations in pressure, but more on a seasonal and not hourly timescale. Not sure how Rehau compares with HDPE in terms of coefficient of expansion and the starting pressures are much higher than my system sees.

Even though system was not running both times, it could be a bit of hysteresis in the gauge with it getting hung when the pumps kick off. Just watch for the longer trends.

at 80 psi, I would think you would see the leak

im with Dewayne

Thanks everyone. When I checked it last night, it had gone up again, and this morning was even higher pressure. Certainly a leak would not cause a pressure *increase*.

They are pouring the concrete today. Thanks again.