My apartment has too much heat. My thermostat registers about 100 to 110 degrees. I've opened windows, but still too hot. According to management of apartments, the boiler is very old and heat cannot be controlled. Boiler is driven by gas. How can I turn my radiators off. The shut off valves were replaced some time ago with individual dials/controls that have never worked. Can the radiators be turned off with a wrench or pliers?