Could be the timing is a little fast.
about 30$ to do it yourself, maybe less.
bad water pump or thermostat. check both.
Was the gasket replaced? Have you checked the hose and the heater core. Is everything tightened down?
The thermostat is stuck open and needs to be replaced.
Would need to know if car was overheating before waterpump and thermostat was replaced.
because the water pump is not working properly....
Little Jimmy Nelson.
If you personally changed it, I would guess theres some air bubbles blocking the hoses.
Year, make and model would help us help you.
Assuming it did not overheat before you replaced thermostat and water pump you may have installed the thermostat backwards. It is also possible the cooling system wasn't refilled properly and was air bound.