I've got an earth stove model #wp50 Pellet stove. I bought it used, it's been working great. Now the dual room blowers won't shut off once the stove is running. The blowers stay off untill the stove gets up to operating temp, come on but will not turn back off like they did when I bought it. I can turn the wall thermostat down all the way but it makes no difference. I can shut the stove down and the blowers will run till the stove cools down and then shut off like before. The blower speed control has never worked, but the blowers did cycle on and off till now. Any ideas? Thanks