Furnace shuts off burner with no warning every three or four days. It shuts off the gas to the burners. The induction blower keeps running and the pilot stays lit. To get it running again, I shut off the power, turn the knob on the Honeywell VR8440 to the off position. Wait several minutes, turn the VR8440 knob to the on position and turn on the power. It comes back on and runs normally for three or four days. The day before this problem started every time we used the gas range the flames were totally yellow. Later that same day they were blue again. Could the gas company have had either dirt or moisture in their lines that is affecting the Honeywell gas control ?