Water isn't flowing through radiator unless you press the gas pedal, acts like its running hot but temperature gauge never shows it going above normal . Thermostat is new and temperature sensor is new , could it be the water pump?
TL DR: It could be the water pump, but maybe not.
Yes, it absolutely could be the water pump. If the vanes of the water pump are corroded and only partially there, it wouldn't transfer much coolant until it gets to a higher RPM. About the only way you are going to be able to tell if this is your issue is if you take the pump off.
There is another theory I'll throw at you though ... the engine and cooling system could be running just perfectly. The thermostat's job is to direct traffic (flow of coolant) which helps keep the engine at a constant temperature. If the engine is cool or the right temperature, it won't flow it through the radiator, because the engine side coolant isn't hot enough to open the thermostat and allow it to flow. If this is the case, it might not be much (or very little) flowing through the radiator at all. You may want to just let it ride, especially since you've stated the temperature sensor doesn't get above normal anyway. If you're not getting any signs of overheating, that may just be because everything is working as it should be.