You don’t have to put in bottle warmer after freshly pumped. Can just put at room temp for max 4 hours. Once you put in bottle warmer to pump you need to use within max 2 hours. If not throw away if baby doesn’t consume it. Otherwise just store the milk in fridge or freezer.
From what i understand, you cant keep in the warmer for so long. Also, if baby has already drank from the bottle and did not finish it, you cant heat up n feed within 4h. From what i understand once it has been drank, you need to finish by the next hour..