However if you live in the countryside and have a well water supply your water pressure is likely controlled by your well pump pressure switch.
Well pump water pressure varies.
If the plumbing system in your home or the mains pipes supplying your home are many decades old chances are they may be clogged constricted and filled with debris.
If the overall water level drops that will reduce your storage above the pump and often also reduce your recharge rate.
As pipes leak or clogs move around inside the pipes water pressure can vary and fluctuate.
This can be compounded if the overall water level in the well varies since the water in the well above the pump serves as a store of water that can be pumped out without needing to be immediately replenished.
Basic well pump water pressure guide if you live in a highly populated area your water pressure is controlled by the municipal water system and is usually around 60 psi pounds per square inch.
If you think your hot water piping is clogged see clogged supply pipes hot water.