An electrician friend of mine told me to get a Marley 2500 heater, and I was wondering if there's any specific order to connect wires to outside of no crossing color paths outside of the heater itself?
The manual can be found here: http://www.marleymep.com/en/assets/pdf/5200-2194-010.pdf
We're wiring the left side with a switch.
Best Answer
If your thermostat control is double-pole, then it doesn't really matter which switched wire gets connected to which heater wire. But if the thermostat is single-pole, then as HighInBC says, make sure it switches the hot wire.
With the single-pole, looking at figure 5 in the referenced manual, connect the switched hot to field wiring point L2, ie. the safety limit switch. Connect your neutral to field wiring point L1, ie. the heater element.
That way, when the heater eventually stops working because the thermostat has failed or the safety limit switch has opened, and you or your dad stabs the element with a screwdriver, you probably won't die.