How to tell if electrodes have deteriorated?

sunlight33

Today I checked ignition electrodes and found two small orange color spots on the leads that look like rust. Also there is a thin grey layer on the leads when I compared to the new one. Will this affect its performance? How do I know when I need to change them?

HomerJSmith

I'm not sure what you're asking. Ignition probes in a spark ignition sys do get dirty and this will affect the ignition and rectification current over time. The orange spots are combustion deposits.

I use a dremel type tool with stainless wire wheel brushes and I clean the probes. You can also clean them with wet & dry silicon carbide sandpaper. I do not use emery cloth to clean them. I have pulled probes out that were almost all orange and they cleaned up fine and a check of the current draw showed that they were as good as a new probe.

I buy my brushes from Harbor Freight, item #66129.

EBEBRATT-Ed

Are you talking about the electrodes themselves or the lead wires?

sunlight33

EBEBRATT-Ed said:

Are you talking about the electrodes themselves or the lead wires?

Sorry for the confusion, I meant the electrodes themselves.

HomerJSmith

In my experience they don't deteriorate, just clean the them. The only time they need to be replace is when they ground out or you don't want to clean them. Make sure any grounding green wire is firmly attached and grounded.

STEVEusaPA

The green wire has nothing do to with oil burner electrodes.
There is a way to actually check them with your meter to see if the porcelains are bad.
They basically need replacement when the porcelains are cracked, then ends don't come to a sharp point, or you don't/can't clean the carbon off of them. If they are really bad, I usually just spray them with Kroil, hit them with a brush, wipe them off.
If you are using interrupted ignition, you'll probably never replace them. Some techs up in New England replace them every year. I've probably only replaced maybe 5 sets of electrodes in the last 10 years. I replaced one set on a Riello because I cracked them over tightening them.
But to your original point, it's also important to figure out why they are dirty, i.e, back pressure, lack of combustion air, etc.

HomerJSmith

Are we talking about oil or LP or Nat gas? I'm confused.

STEVEusaPA

LOL, now I am too. I hear electrodes and think oil.

sunlight33

It's for LP mod-con boiler.

STEVEusaPA

sunlight33 said:

It's for LP mod-con boiler.

Oh then disregard my comments...

HomerJSmith

My experience is that LP electrodes dirty faster. I was previously speaking of almost all orange on the electrode as being from LP fuel. Maybe that is because of the combustion not being set correctly.

EdTheHeaterMan

STEVEusaPA said:

The green wire has nothing do to with oil burner electrodes.
There is a way to actually check them with your meter to see if the porcelains are bad.
They basically need replacement when the porcelains are cracked, then ends don't come to a sharp point, or you don't/can't clean the carbon off of them. If they are really bad, I usually just spray them with Kroil, hit them with a brush, wipe them off.
If you are using interrupted ignition, you'll probably never replace them. Some techs up in New England replace them every year. I've probably only replaced maybe 5 sets of electrodes in the last 10 years. I replaced one set on a Riello because I cracked them over tightening them.
But to your original point, it's also important to figure out why they are dirty, i.e, back pressure, lack of combustion air, etc.

sunlight33 said:

It's for LP mod-con boiler.

STEVEusaPA said:

sunlight33 said:

It's for LP mod-con boiler.

Oh then Nevermind...