[Viso1964]

I take it that thermostats are a bit different from other electric heating devices. and I needs some help in determining what I have and what replacement I should get.

Current Setup
Current is supplied by a twinned 30 amp breaker on a 240v system. Tests on the lead wires indicate 120v on each (testing black-to-ground and then white-to-ground) and 240v when testing black-to-white. The heaters include 2x 1500 watt electric baseboard heaters and 1x 1000 watt fan-forced electric heater. So total wattage is 4000.

Power supply comes in to the thermostat by a single heavy-gauge black wire. This runs through the thermostat and then returns to a cap which sends the current on through separate wires to all three heaters. The white wires are all capped together and do not run through the thermostat. When I test the supply at all three heaters, I read 240v so that part seems to be working fine.

Current thermostat is a circa-1978 White Rodgers model (166-133?). It is a fairly simple dial-based model with four connectors which are are arranged in an "X" pattern. Supply comes in to top-left and returns to the heaters via top-right. The bottom-left and bottom-right connectors are connected by a single red jumper wire.

Questions
1. Does the current wiring make sense?
2. What type of thermostat can I replace this with? 2-pole? 4-pole? Any other restrictions or specifications?
3. Can someone recommend a simple programmable thermostat that can handle 4000w at 240v?
4. How would the replacement be wired in? Okay, I understand that this is going to be model-dependent.
5. Is this a simple job or should I leave this to a professional?

Thanks,