Faucet problem

The sink faucet in our first floor powder room has never had more than a thin stream of water coming out, even with the tap fully open. I routinely check aerators to make sure there's no gunk gumming up the works, and that's never been the issue with this faucet, which is Jado's New Haven single hole unit. The pressure in the rest of the house is fine. We have a mix of Jado and Grohe faucets. All work great with this one exception.

The plumber I called in told me that problem is in the faucet itself. That at some point —*obviously right after we did our whole house reno 10 years ago, when this bathroom was built —*some gunk got swept up into the unit itself and that it's impossible to take the faucet apart and clean it.

Is this true? But if that's so, then any single hole faucet I replace the Jado with is likely to have the same thing happen to it, right? That's what the plumber contends, anyway. This is a tiny bathroom, and there is literally no room for a bigger sink that would afford me the ability to use a widespread faucet set.

I'd love to know if you guys think there is something else that might be going on in the faucet or if I need to go ahead and replace it.

If the pressure and flow remain constant no matter where the handle is positioned, then the problem IS in the faucet, and specifically after the point where the hot and cold merge to come out of the spout. Whether it can be corrected is something we cannot tell without being their ourselves.

It would be highly unlikely that both supply lines are partially plugged so the flow remains the same, as HJ said. Take the thing apart and remove the cartridge. Put something over the top of it and turn the water back on to see if you now get decent flow. If so, then replace the cartridge with a new one. If not, it is in the spout. If you take the aerator out, you might be able to poke something through there back to the area where the cartridge was and clean it out. All else fails, replace the thing.

It would also NOT be the first faucet which has a casting flaw, so that a "web" was left internally which is restricting the flow.