DIY Home Improvement, Remodeling & Repair Forum

DIY Home Improvement, Remodeling & Repair Forum (http://www.houserepairtalk.com/forum.php)
-   HVAC (http://www.houserepairtalk.com/f8/)
-   -   Oil burner tripping (http://www.houserepairtalk.com/f8/oil-burner-tripping-8486/)

DPJ 01-26-2010 03:37 AM

Oil burner tripping
 
Hi all, Newbie here.
Was looking at some earlier posts on heater problems to see if my problem has already been answered, since I didn't see my particular scenario I thought I'd make a new thread.

The oil burner started tripping yesterday, when I hit the re-set button, combustion is not slow - I get ignition/combustion immediatly and everything seems fine for a while, heater goes through numerous cycles for a couple of hours or so, then it quits again.
I started hanging around to see what happens, and one of two things has been occuring -

1. It is in idle mode, and when it needs to start, the re-set trips before anything happens, blower dosen't even come on. Or...
2. It starts up as it normally would, igniting immediatly, but after it's been running momentarily ( I've seen it happen at just around 10 seconds, or as long as a half a minute or so) it shuts down prematurely in the cycle, (then a few/several seconds later the re-set button trips and red light goes on).

If I push the re-set button after it does this (after waiting momentarily), it always starts right up, with immediate ignition/combustion, runs again cycling normally for a couple of hours, then shuts down again doing one of the above two scenario's.

I cleaned the nozzel, made sure the electrodes are set to spec. (I have paper work for the heater, was new about 10 years ago), and examined the cad sensor and cleaned the glass (it wasn't that dirty)

What else can go wrong that would make this malfunction on an intermittent nature, and be able to fire up again right away and run seemingly well? Could the transformer be unreliable? Cad cell actually bad rather than dirty? Electrodes bad? Bad spot on the motor? I'd love to hear some ideas on what is most likely the culprit before I try to do anything else. Any and all suggestions greatly appreciated! Dan

Hertel 01-26-2010 04:38 AM

Im not a furness guy but ive worked on a few boilers.. If I had to guess I think your loosing flames and then your getting your aslarm because of that... If a safety was taking you out you would get the alarm right away and it would happen more often...

So.

You have a had sensor turning it off... Or bad air flow,oil flow,
You can also put a light pen to your electrodes/ignition coil and make sure thats not cutting in and out while opperating.

Be careful hitting that reset button all the time, if you do that and it doesnt start you have just dumped all that oil into the burner and when that thing fires you might get a fireball shooting out .

DPJ 01-26-2010 08:37 AM

Thanks for the response Hertel. Appreciate the tips.

Quote:

Originally Posted by Hertel (Post 39574)

Be careful hitting that reset button all the time, if you do that and it doesnt start you have just dumped all that oil into the burner and when that thing fires you might get a fireball shooting out .

Yes, I am aware of the hazard of pushing the reset more than once if it dosen't start, thanks.
As said, so far that hasn't happened - it always starts right up when pushing the re-set button. This is partly why I'm confused as it seems to run well for repeated cycles and then just quits.

Wuzzat? 01-26-2010 09:55 AM

Quote:

Originally Posted by DPJ (Post 39572)
everything seems fine for a while, heater goes through numerous cycles for a couple of hours or so, then it quits again.
I started hanging around to see what happens, and one of two things has been occuring -

the re-set trips before anything happens, blower dosen't even come on.
...

after it's been running momentarily ( I've seen it happen at just around 10 seconds, or as long as a half a minute or so) it shuts down prematurely in the cycle, (then a few/several seconds later the re-set button trips and red light goes on).

runs again cycling normally for a couple of hours, then shuts down again doing one of the above two scenario's.

What else can go wrong that would make this malfunction on an intermittent nature, and be able to fire up again right away and run seemingly well? Could the transformer be unreliable? Cad cell actually bad rather than dirty? Electrodes bad? Bad spot on the motor? I'd love to hear some ideas on what is most likely the culprit before I try to do anything else. Any and all suggestions greatly appreciated! Dan

What takes a couple hours to happen? Probably nothing thermal, but maybe an intermittent connection. Post a schematic, and wiggle wires to induce the fault.

What takes only a half minute to happen? Monitoring test points may help here.

You may need to rent or make an Event Recorder; it babysits the system, triggers on the fault and then reads back the data from test points that is stored in memory.

My furnace people sent me a factory service manual for free. Sequence of operations, schematic, etc. You might try to get one.


All times are GMT -6. The time now is 12:17 AM.