Furnace won't blow warm air...but cold air is fine. HELP!!!?

Question

Hi All,

I have an oil furnace in a house we just moved into. The unit is for the heat and cooling together. It will blow cold air when AC or heat is on, but no hot air. Any suggestions? We have tried re-setting the furnace, and that doesnt work. We have also thought that maybe it was the thermostat but that also seems to be working just fine. Any suggestions would be greatly appreciated. We really don't have the money to call someone to come look at it.

The house I lived in before this one we had oil heat too...so I know what it sounds like when the burner comes on, and I'm pretty sure that it IS coming on in our new house. And yes...there is oil. That was the first thing we checked LOL.

Answer 1

When heating with oil there is no pilot light. The oil goes from the tank to the burner and the pump pressurizes the oil to 100 psi (usally). The oil then comes from the pump through the nozzle and is atomized. The transformer creates a spark that ignites the oil spray.

A primary control takes input from the thermostat and tell the motor and transformer to run. If the primary doesn't see a fire in X amount of seconds (X could range from 15 to 90, depending on the age of the unit), it will shut everything off.

What you are hearing the motor running. DO NOT CONTINUE TO PRESS THE RESET BUTTON. Every time you press it, 15-90 seconds of oil will spray into the chamber (if you have oil, the lines are not clogged, the pump is good, yada yada yada).

When the service tech comes out to fix it, the unit will smoke very heavily for some time, depending on how much extra oil you let into the chamber. Just think - when the tech fixes the fire, it will need to burner ~2 minutes of oil all at once - it will not have enough air to burner that much oil, and therefore it will be a bad, smoky fire for a short while.


My answer - call someone to fix it before you fill the chamber with oil and have to spend MUCH MUCH more than it would cost if you just have someone come out. More than likely a part is bad (pump, transformer, oil line, nozzle).

Answer 2

The first thing is BECAREFUL when working with FLAMES and FUEL!!!

It sounds like that the "Pilot light" is not functioning and this can be due to the fuel supply not flowing, or the thermo-coupling not functioning correctly.

Try to directly light the pilot light with a long lighter and watch the flame after you light it. If it stays lit then adjust the thermostat to ON - HEAT and look at the burner again. If it remains lit and you still cannot feel heat out of the vents then check for a blockage in the ducts.

If the flame goes out as soon as it lights or it fails to light. Then the thermo-coupling is probably bad and must be replaced. and it is not very expensive or hard to replace and can be bought in most hardware stores.

Hope this helps.

Answer 3

Is there any oil in the tank, NO FUEL=NO HEAT. If you are not familiar with an oil furnace, you will need to contact a serviceman to fix the problem

Answer 4

Is the burner coming on? You should be able to hear that?

try this site: http://www.homeheatingservice.com/Furnace_Troubleshoot.htm