I have a 3 family home and am having a problem getting the heat up to the third floor. Right now the thermostat is in the basement and the sensor is in the first floor apartment. Where should the thermostat be placed? In the first, second or third floor apartment for me to better manage the heat and make sure everyone is warm. Thanks for your help

I don't think moving the thermostat will solve the problem. If it is a single zone forced air system, you need to rebalance the duct work. Start by checking any ductwork you can get at. Look for obstructed vents, leaks, and closed dampers in the third floor ducts. Fix any problems you find. If you don't find anything, you will need to reduce the air flow to the lower floors. Instal dampers or blast gates on the ducts to the warmest rooms. That will cause more warm air to flow to the third floor before the thermostat shuts the furnace off.

Thank you for getting back to me so quickly. The system is not a forced air system. I have radiators in the apartments and it's a gas boiler. I believe it is a hot water system. Not steam. Does this change your thinking? Thanks

That opens new possibilities. It is possible the system is low on water and none makes it up the third floor. How is the system piped up? Does all the water pass through all the radiators, or is each floor a different branch? Are there zone valves? I don't have a lot of experience of hot water systems.

thank you for getting back to me so quickly. the system is not a forced air system. I have radiators in the apartments and its a gas boiler. I believe it is a hot water system. not steam. does this change your thinking? thanks
.. if the system is hot water; does each floor have its own balancing valve... one of the choice you have it balance the water flow== balance the temperature (((** balancing valve should be globe or ball valve)))... leave the sensor where it at now; try to balance the water flow first... relocate the sensor to another location won't solve your problem... ***... this is 1 more solution... you could reduce the temperature in rooms that are HOT by reduce the opening of the air vent(radiator's cover louver) or/plus cover up portion of the effective length of the radiator ( use foil or sheet metal)... did you try to bleed out mostof the air in the water..?

Thanks for your help. I had messed up the thermostat and had to reset it to the factory settings . Now it is getting the heat up to the 3rd floor but I am having a different problem now. Hope you can help me. As I mentioned before the thermostat ( white rodgers 1f97-371) is located in the basement apt and the sensor is on the first floor apt. The thermostat is set for 72. I have been noticing that the thermostat will call for heat to get the apt to 72 then shut off and then a few minutes later (about 5 ) the thermostat will go on again even though the apt is at 72. It will stay on for about 5 or 10 minutes more then go off . About 15 minutes later it will go back on even though the apt is satisfied at 72. Any suggestions? Thanks for your help

I wonder if the sensor is too close to the radiator? The area near the radiator heats up shutting the heat off. The heat then flows into the cold room, turning the system back on.

No the sensor is not near any radiator or windows. Im thinking maybe it just keeps current the 72 degrees. Ive been monitering it now and it hasent come on in an hour now so maybe it was just maintaining the 72 degrees and anticipating that it was about to go lower. Does this make any sense? If so then there probably isn't a problem and Im just overreacting to all that has been happening lately.