Are programmable thermostats compatible with steam heat systems? Seems like radiators are not getting hot enough. Air valves were replaced. Not sure why steam is not reaching radiators.

If the old thermostat was a simple 2 wire one, connecting the 2 wires to RH and W should work. Otherwise, you may have to give some more details.

Jump the thermostat out and let the boiler run. Then see if the radiators get hot. If they do the thermostat is the problem.

Steam takes a different setting if you are using a digital thermostat.