desel furnace heater for the mushroom grow .The temperature in the room is demanded on about 14 degree Celsius。When the weather is cold ,furnace often burns only few seconds and then shuts off and can not self start. If heating the furnace with other electric heater,it will work normal .The furnace continously blows. I think the blower has problem。But the mushroom needs fresh air ,so we hope the the furnace can continously blow.What can we do for self start?