We have a home on a concrete slab in Texas. A week ago, we lost quite a bit of our water pressure. There is not a leak in the pipes coming to the house. Also all lines are made of copper. Is there a way to check the inside pipes to see if there is an obstruction in the pipes somewhere without having to go into the walls. This house is 25 years old and we have owned it for 3 years, so we are not sure where all the pipes are and how they run. According to our meter we have not lost any water. Our city crew suggested that there could be corrosion in the pipes. How would a person check this? Thank you.

Turn off water at the street. At the main shut off valve in the house attempt to remove the stem. If you can remove the stem, inspect and replace the washer. If you cannot remove the stem you will have to replace the valve.

Let's try and narrow this down a bit.

So every tap in the house has low water pressure?
Does it initially come out fast and then slow down to a trickle, or is it always slow?
Do you have a PRV (pressure reducing valve) near the inlet?

I wonder if this should be moved to the plumbing section...