Have a heat only furnace reran new wirex3 red white green hooked up to new stat now will not turn on at all furnace or fan that is trying to heat house with wood burner and just run fan

Tell me you turned off the power to the furnace when you made the changes! OK, now look for a in-line fuse or one on the board. Typically the red and white wires are used for heat and the red and green are for the blower. Make sure red goes to R, white goes to W and green goes to G on both thermostat and furnace.