Bathroom replumbed - little hot water in sink

Yesterday we had part of our bathroom replumbed with PEX. All the work is still open and accessable. We have two sinks in the bathroom. Neither one was plumbed, but one of the sinks now has very little hot water.

I am figuring some dirt or particles got in the valve (single handle) and is restricting the flow. Is this a good guess?

Anything else I should check?

Thanks!

That's as good a guess as any. Are you sure the shutoff valves are fully opened? Some faucets have filter screens on their inlet. Sometimes you have to remove the cartridge, sometimes the supply line; sometimes it is crud in the aereator. Unscrew that and see what it looks like first. Turn the water on with it off and see...clean it out if it is full of crud.

very common

to have debris dislodged in pipe when repiping. Lines should be bled out before installing to fixtures. Remove the aereator and clean if needed. If that doesn't help, turn the hot water off for that fixture, remove the supply line from the fixture, point supply line in a bucket and check the hot water flow. If that is okay, then the problem is prob debris in the cartridge/stem. Sometimes, they can be flushed out, but you might have to buy new.