radiant heating

My eichler still has the original radiant heating system and is working fine. My problem is that a portion of the house has hardwood floors. It takes a very long time for that section of the house to warm up. Generally it takes up to three hours until you start to feel the warmth in that room.

So basically the boiler is running nonstop for a long time to maintain the room temperature where the thermostat is located.

Does anyone else have this problem?