Jump to content

Wacky Oil Heater

John Raffensberger

Recommended Posts

This might be easy for one of you but it stumped me, and my client who seemed to know his way around a house.

The system was serviced 5/3/05 and it was 78 degrees out and the power was on.

When I adjusted the aftermarket thermostat up the furnace did not respond until I hit the reset button on the furnace and then only the pump motor turned on, the furnace did not light and system cycled off.

Also, the fan/blower did not respond to the thermostat but did turn on manually.

The oil tank was buried so we couldn't check level.

My thoughts: No oil in the tank and bad fan/thermostat connection.

Thanks for the help.


Link to comment
Share on other sites

Sounds like it's out of fuel or there's water in the fuel line.

Get some Kolorcut and pick up a cheap tape measure that you're only going to use for fuel tanks.

Stick the tank next time using Kolorcut. You'll know whether it's out of fuel and, if not, how much water there is in the tank. More than about 1/2 to 3/4 inch of water in a 275 gallon tank and you could have a hole in the tank that's admitting water. Holes in the tank are bad ju-ju.

OT - OF!!!


Link to comment
Share on other sites

Well, the furnace is not lighting properly and going off on reset hence having to hit the reset button to get it to try and fire again. There could be numerous reason for this, defective ignition system (spark igniter etc), a oil supply valve inadvertently turned off, lot's of things could be wrong.

If they have a buried oil tank then somewhere in the home they should have a wooden stick, with graduated markings, that you would put in the tank to measure how much oil is left.

How did you turn the fan on manually, at the fan/high limit switch? What you find typically is that they didn't run the green (fan wire) low voltage wire to the thermostat sub-base. You might just find the red (power) and white (heating) wire run to the t/stat. You have to pull the stat off the sub-base to check (outside the scope of a normal inspection).

Heating did not respond to thermostat, have a licensed HVAC contractor inspect/repair.

Link to comment
Share on other sites


Around here, most of the oil furnaces have a separate switch to run the fan in hot weather. It's a cheap way to cool a home if you've got a basement and it helps to dehumidify the home.

typically, you'll see one switch for winter that allows the burner and the blower to operate as a heating unit and the second switch will only be turned on in the summer when the heating switch is off.

Had one the other day though where the blower only operated when both switches were on and the stat was calling for heat. The fan switch would not allow the blower to run separately in summer without the burner.

How long has the tank been in the ground? Around here, a tank in the ground 40 years is a leak waiting to happen and I tell 'em to get them replaced or be ready to deal with an eventual remediation.



Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Create New...