Nordyke MH series gas furnace

wyork

Furnace pilot stays on furnace ignites. Stays on all day, however goes out at night. Trying to figure out the prob 

EdTheHeaterMan

Is this a consistent problem? I mean, does it happen every night? When did the pilot outage start? This week, or has it gone on for months?

There are many reasons for this. If the flame sensor is getting weak. Thermocouple or PowerPile Generator are the two most common flame sensors for standing pilot. If they are old, they could be getting weak. If they are weak then they may work fine for hours. Then at some odd hour of the day, something changes. Like maybe at dusk there is a wind shift every evening. that may change the vent draft just enough to pull the flame away from the flame sensor to read a "NO FLAME" condition. Even if the flame is still there, once that "NO FLAME" signal happens long enough, the gas valve will close off the pilot gas.

Another condition could be that everyone in the neighborhood turns up their heat and the very cold weather causes the main gas pipe to be over used. The pressure in the main drops and your pilot gets just small enough to read as a NO FLAME condition.

So @wyork
First, I would see if the pilot burner needs cleaning.
Replacing the thermocouple (or Pilot Generator) may solve the problem.
Or of you are not the DIY kind of guy, you can call a Professional

any more than that and we will need more information about your model and brand of equipment. or post pictures... lots of pictures of your heater and controls and what the pilot looks like