Advice on fixing overheating issues ?

[unitt01]

My car overheated on me heading home from work a few nights ago and it only got to be driven for about 4 days after its engine rebuild and the 5th day i gassed it a little and it overheated quickly. pulled over checked the engine and the coolant cap released its "pressure valve" which spit some coolant around the coolant tank. Today I did some diagnostics towards the coolant system and checked the hoses that go towards the thermostat housing and those were hot and the hose on the bottom of the radiator is cool, still need to check the fan viscous coupling by seeing if the fan stops. Didn't find any leaks on any hoses.
When I did the engine rebuild I got a new thermostat, water pump and coolant sensor so is it possible one of those went faulty ? Any other things I should look into ?

I'm also going to flush my coolant and try to release air that might be stuck in the cooling system since that night obviously there was too much pressure

Any advice is appreciated thanks!

[digger]

both hoses in and out of rad should be hot if the coolant is flowing. one will be hotter than the other but still not cool. check t-stat opens properly and make sure radiator isnt blocked IMO