Is this a new install?

What is the voltage of the heaters?

If it is 220, is the breaker installed properly? Is it a double pole breaekr or two tandem mini breakers. What is the voltage between the two hot wires.

More details of the complete wiring would help also.

replacing old, for some reason two of the heaters in the room quit working. so i looked into it and found that they were getting power so it had to be the heater, so i bought a new heater but nothing happened. voltage is 220 at each black wire coming out of wall for thermostat and heater. it is a double pole breaker. there are two sets of wires at each location which come from the box. the thermostat is a 4 wire, and at the heater they had the 2 white wires twisted together, and then black on black. I don't know what else to tell you about it. it was working last year, could something have happened, like the breaker went bad? but i am still registering power at both locations.