[percygreen]

My oil-fired floor furnace will run through two cycles before the reset button on the primary control trips. When it's running, it runs smoothly with no problems. The tank wasn't empty when the problem began yesterday, and it was filled this morning.

The nozzle, electrodes and oil filter are only a few months old. The transformer, primary control, fuel pump, coupling, and motor are all less than a year old. Any ideas?

 

[yuri]

Just Bcause they are less than a yr old does not mean they are not dirty or fouled up. A bad flame can foul them up in a day or 2. Get it checked by a Pro.

 

[beenthere]

How low was the tank.

 

[percygreen]

It was half full (it's a 250 gallon tank). I changed the oil filter today, even though the old one looked fine, but the store didn't have my nozzle size. I've got a cad cell (the only part I've never replaced) and nozzle coming tomorrow. Hopefully that takes care of it. If that doesn't work, I guess it's time to suck it up and call someone.

Just to ease the mind of anyone who's worried about a "civilian" playing with his furnace, I was a plumber for 15 years and I now work at a plumbing/HVAC supply house. I don't have a lot of experience with furnaces - I've mostly done water/waste pipe systems and I've worked on a couple boilers, but I am somewhat familiar with how this thing works and with the industry in general. In other words, I know my limits. I'm just trying to find out if this is a common problem with a simple solution.

I'm also trying not to dump much money into it. We're installing a heat pump this spring and getting rid of the oil furnace altogether. (It'll be so nice to be warm in EVERY room of the house instead of just the ones adjacent to the living room!)

 

[techpappy]

Check to see if condensation building up on cad cell. Just one of many possibilities.

 

[He123321]

Where is your oil tank located at, inside/outside? If its outside, do you have heat tape/insulation installed on the oil line? The only time I ever had such problems was do to the clod weather outside.

 

[percygreen]

Changed the cad cell and the wires leading to it. It still trips on shutdown. I redid the wire connections for the thermostat while I was at it, just to make sure they were nice and tight. Changed the nozzle and filter just to be sure I'd done everything I could think of (Both were still clean), and I looked at the electrodes, which are positioned correctly and still have a nice, fine pencil point on them. I've talked to a service guy at work and warned him that he might be getting a call this week. I don't mind paying someone to do it so long as I've tried everything in my power first.

To answer your question, He123321, the tank is outside, but I'm getting nice, clean oil all the way up to the pump. It's been cold here, but not below freezing. The house has never gotten colder than 55 degrees or so, according to the thermostat, and when I reset the control, it warms back up to temperature.

Anyway, thanks to everyone for your help and suggestions. Hopefully the service company can keep this thing running for another two months. By summer, I should have a nice 15 SEER heat pump and I'll have a nearly full oil tank to sell.

 

[beenthere]

Probably a transformer getting weak after it gets warm/hot. needs to be tested. As any component should be before just replacing it(exception being a run cap).

 

[old_squid]

Hopefully that takes care of it. If that doesn't work, I guess it's time to suck it up and call someone.

Just to ease the mind of anyone who's worried about a "civilian" playing with his furnace, I was a plumber for 15 years and I now work at a plumbing/HVAC supply house. I don't have a lot of experience with furnaces - I've mostly done water/waste pipe systems and I've worked on a couple boilers, but I am somewhat familiar with how this thing works and with the industry in general. In other words, I know my limits. I'm just trying to find out if this is a common problem with a simple solution.

Having worked on oil equipment for almost 20 years I cringe whenever I see someone that has limited experience doing it. The problem with oil is that when vaporized (sprayed through the nozzle, expecially into a warm heat exchanger) and it doesn't light right away, it can cause rapid and uncontrolled burning. :whistling2: If you don't know the short definition of that it's called an explosion.

Of all the fuel burning equipment I've worked on the only ones that have outright tried to seriously hurt me or kill me were the oil ones when they delayed on ignition.

I hope you find the problem, but please be careful.

 

[percygreen]

Which is exactly why if it had been an ignition or oil problem, I wouldn't have fooled with it at all. I know all about the sudden "boom" when an oil furnace finally kicks on after several repeated failures - a functioning pump and failing ignition is a horrible combination. Whatever my issue is (and I should find out tomorrow when the tech gets here), it's neither of these. It's happening when it shuts down after a cycle. To further ease your mind, we've placed space heaters around the house to keep it tolerable until the furnace is fixed, and I've shut off the power switch to the furnace under the house so there's no way it could come on. As someone who spent years working with soldering torches under sink cabinets, I try to be as cautious as possible.

 

[COLDIRON]

Hard to say but I am always suspicious when the oil tank is filled and the heater is running. Stirring up any sludge from the bottom of the tank going into the oil feed system.
I like to have my tanks filled with the burner off for a while until everything settles down.