My 1998 honda accord 6 cylinder radiator

@firmeonmine

First make sure you have enough coolant. Check your fans and make sure that those are working properly. Let us know if they are coming on at proper temperature. Since your thermostat is new check for proper installation. The upper and lower Radiator hoses should get warm during operation of the engine. If the upper hose is "HOT", and the lower hose is "COOL" then the thermostat is not opening. If both the upper and lower hose are hot it is possible that this is a water pump issue or a clogged radiator (unlikely). You can always try a coolant system flush. Let us know if you have to frequently add coolant. If so check your engine oil. Let us know what it looks like as well as the spark plug faces.