Electric Heat Thermostat Wiring
That will work.
It actually does not matter &quot;which of 3,4 connects to L1, L2&quot; nor &quot;which of 1,2 connects to T1, T2&quot;, but conventionally you would like to keep the same color on the same side.
i.e. L1 -&gt; 3 and L2 -&gt; 4 works no worse nor better than what you had - in 240V single phase the lines are interchangeable.
It's also polite to put red or black tape or paint on the white wires, but normally considered &quot;obvious&quot; in this application.