Wiring an electric Fireplace for 240v.?

After wiring my cct brkr for 240v I had to have a repairman come in to see why my fireplace did not produce heat. He found that with the 4 wire connection, recommended, I was getting 117v from red to white and 117v from black to white. The problem being is that I also only read 117 from black to red, where it was expected to read 230-240v. Checked the wiring for my dryer which is also 240v, 4 wire and it did read 240v from black to red. Why do I only get 117 when I should be getting 240v?