Since installing our Peerless Faucet with sprayer model P99578-L, our water pressure at the kitchen sink decreased. I adjusted to this but the past 6 months has been unbelievable. It takes me 30 minutes to run a sink of water to do dishes! The only way to get water that is hot enough to wash dishes is by using the sprayer and the faucet together to fill the sink (it still takes a good while to fill the sink even with both of these working together). When just using the faucet (the hot spout) the water is barely warm and will be cold before doing the dishes. There is plenty of water pressure in the sprayer and the amount of water coming from the kitchen spout is almost the same, about the circumference of a pencil, whether I am using the water sprayer or not. Something is obviously not right here. Please help!:(

Try removing the aerator and tell us if you get more water. I think you have debris in the aerator.

In the aerator, there are three mesh screens, one two-part white plastic covering and one black rubber seal. There doesn't seem to be anything clogging it up. When I leave the two-part white plastic covering out of the aerator, I do get more water pressure. Any reason to leave it in if it is the reason the water is not flowing?

Put the aerator back the same way you found it. It think the problem is in the valve,(see image, ) or supplies. Shut the water off at the stops and open up the faucet. Check for any trash in the cartridge inlets. Now turn on the hot and cold for a minute to flush out everything. You should have a strong stream coming out of the open valve body, if not click on back. Reassemble and test. Good luck, Tom