why do my radiators cycle hot and cold in the winter
Just like a forced air furnace, your thermostat controls the heat in your apartment. When your apartment cools the thermostat tells the boiler and a zone valve heat is needed. Your zone valve opens on a call for heat allowing hot water to flow through your radiator and cycle in the system heating your apartment. After the desired temperature is reached the zone valve closes shutting off the flow of the hot water so as it cools from not being cycled through the boiler is why your radiator cools until there is a call for heat again.
