So we had a weird issue with the hot water over the weekend

it was very slow and never got really hot

They had installed the rough valve but we didn't have the cartridge for the shower valve yet

might this have caused the hot and water to crossfeed through the rest of the house?

@Aaron Cross feed would show up more as hot water on the cold side. Sounds more like you have a blockage somewhere, maybe a failing valve, those always seem to happen when you use them.

the rough in valve is one with screws on either side of the inlets

presumably so you can replace the cartridge without turning off the water to the whole house

so they closed off both the screws and it seems to work normally now

@Aaron If those valves were open without a cartridge, how were you not getting water spraying in the shower?

paint on the walls (2.5/4 walls in the living room complete). Though we're not sure if the color is the one we ordered :(

@BMitch that was also a very good question, but I think there's some other piece that it ships with that goes in the valve

I'm not completely sure how it operates

deltafaucet.com/bath/details/r10000-unbx.html

That's the valve body

The cartridge comes with the trim piece

@Aaron very curious. Still not sure why the water was slow, or are you just saying it was slow to heat up but still at the normal pressure?

Yeah, I mean it was slow to heat up

like it took a lot longer than it usually did, and some fixtures never got as hot as they used to

the pressure was unchanged as far as I could tell