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How did i get so many?

Cleaning out one of the vans! Can't believe all the stuff that was found.
Ended up cleaning then testing the ones that looked ok on the shop furnace.

I must say, I ALWAYS clean flame sensors with sand cloth. I have never had issues with said flame sensors ... ever due to sand cloth cleaning...


Stay safe out there bros.

Originally Posted by rich pickering

we had a guy use a screwdriver as a temp rod. It worked.

Bingo, I taught our guys to take proper reads FIRST and then if in doubt use jumper and screwdriver and also take read from that.

Originally Posted by Kevin O'Neill

Some boards look for micro-amps, some tenths of micro-amps. Always DC.

Thanks that would explain it. Maybe my meter wasnt sensitive enough to read the Micro amps on this particular unit although i know i did read .1 uA on a unit befor i cleaned it. If it was much less than that i doubt my meter would pick it up. Giving the size of this flame rod it would make since it feeds back less uA . Thanks again good to know

Some boards look for micro-amps, some tenths of micro-amps. Always DC.

Originally Posted by hurtinhvac

I've always wondered: Why would you check ground if you are getting adequate uAs DC? Don't the uAs depend on a good ground?

It is a circuit, afterall...?

I've never had to replace one yet, and don't expect to any time soon. Also, I like just a little abrasiveness when I clean them - so I make little custom pieces of emory cloth by turning the rough surfaces on each other and sanding off and smoothing them quite a bit. Then simply turn the cloth over to the smooth side for a polishing when I'm done cleaning with the smoothed, formerly abrasive side.

Same here, unless its friday and I still have a dollar bill.

I've always wondered: Why would you check ground if you are getting adequate uAs DC? Don't the uAs depend on a good ground?

It is a circuit, afterall...?

I've never had to replace one yet, and don't expect to any time soon. Also, I like just a little abrasiveness when I clean them - so I make little custom pieces of emory cloth by turning the rough surfaces on each other and sanding off and smoothing them quite a bit. Then simply turn the cloth over to the smooth side for a polishing when I'm done cleaning with the smoothed, formerly abrasive side.

Originally Posted by itsiceman

I the meter at school a better meter?

No, same meter. ❓

Originally Posted by LKJoel

If its just steel, with no special coating, why not use sand paper or emery cloth?

Scratching and scarring the surface causes it to get dirty faster.

The glass in the sand will insulate the the rod making it useless

Originally Posted by beenthere

Its just a piece of metal. Clean it with steel wool or a dollar bill, never sand paper or emery cloth. Its good to go. As long as the ceramic isn't broke, it isn't pitted or physically broke.

If its just steel, with no special coating, why not use sand paper or emery cloth?

Originally Posted by chaser310

I have a hand full of f/s . Was just wondering can they be tested out of a furnace with just a flame (torch or lighter) and meter? Kind of like testing a t-couple on a bench? If not I will just check them on the shop furnace.

Thanks

Its just a piece of metal. Clean it with steel wool or a dollar bill, never sand paper or emery cloth. Its good to go. As long as the ceramic isn't broke, it isn't pitted or physically broke.

Originally Posted by Core_d

I can't get a uA reading on my home furnace at all. Its an janitol with a spark igniter. flame sensor is coming from ignition module i know its good if i unplug it durners shut down and spark starts up and i know my meter is good ive tested the sensors at my school the same day. This has been bugging me can anyone please give me an explanation?

I the meter at school a better meter?

Originally Posted by LKJoel

I was always told that flame sensors had a coating on them that helped the flame rectification, and that if it was damaged, it would not pass through the correct flame signal

Is this accurate? Or was somebody misinformed

No, it needs to be the bare metal. A coating of any kind will cause more resistance.

Due to their environment, any flame rod must be made of a corrosion resistant material. If you get dirt or pitting from arcing, you can get signal degradation.

A lot of effort for little gain.

Throw them in with your igniters. If you think you have a bad one on a call replace it with your stock. If still doesn't work, get a new one.

Flame sensors I've changed in close to 20 years:

Trane on LP. They seem to burn a grove in the rod and break.

Rheem. Two occasions. The sensor looks good, just didn't work. Replace the sensor and all is good.

Carrier. Ceramic broken and rod spinning. But it worked until the next day when I replaced it.

BTW, how did you get so many flame sensors?

we had a guy use a screwdriver as a temp rod. It worked.

Originally Posted by littlebigdad

Maybe I'm doing something wrong but I haven't replaced maybe a dozen flame sensors in 25 years

Usually, guys condemn them as a part of "shotgun service"

Can't figure out what's wrong, so they order a module, a spark electrode, a flame rod, a gas valve.....

Maybe I'm doing something wrong but I haven't replaced maybe a dozen flame sensors in 25 years

I can't get a uA reading on my home furnace at all. Its an janitol with a spark igniter. flame sensor is coming from ignition module i know its good if i unplug it durners shut down and spark starts up and i know my meter is good ive tested the sensors at my school the same day. This has been bugging me can anyone please give me an explanation?