Any Thermocouple Experts Here?

[hawg]

Can a thermocouple be ID’d from the number stamped on it? I was getting these from ASAP Heating but they are sold out and I have searched with no results. This is for an Orbis Colorama 20,000 btu direct vent wall heater I have in my fish house. Orbis went out of business about 10-12 years ago but I can’t believe they made their own thermocouples. I’ve tried some pretty big plumbing & Heating suppliers with no luck. The SIT numbers are stamped into the wire/tube part. Numbers have different first 3 numbers but came from ASAP and fit the same. Can anybody help?

[kc_]

Try amazon. type in universal direct vent gas stove thermocouple

[Ronnie D]

The only difference on thermocouples are length & thread ( some are reverse / left handed threads) . They all create the same micro amp current when heated to establish pilot safety & allow main valve to open. Any HVAC supplier, hardware or bigbox store will have em in stock. The stamped part # you have is a manufacturer part # probably made by Honeywell or White Rodgers which allows them to call it O.E.M & mark up da $$.

A generic one should run under 20.00
& comes w/ multiple sleeves to fit any pilot assembly

[mugsy]

[hawg]

Thank you guys. My first number in the diagram should have been 5/16, not 5/6. Dropping the first 4 numbers in the part number like you guys showed me was my problem finding the same thermocouple and why the two I had began with different numbers and were the same part. The heat exchanger end diameter shows 6.49 mm and necks down to 5.94. From that neck down, shoulder, to the tip it’s about 1 3/8 inch. I have to believe that’s a very important number so that the thermocouple seats at that neck down and the tip of it is in the pilot area. Wouldn’t that screw me up from using a universal thermocouple unless that distance was the same?

[esox_xtm]

There is often some latitude for thermocouple adjustment. But you are right, that tip's gotta be at the very tip or in the flame.

[Ronnie D]

The sleeves & insert clips that comes w/ da kit will allow to slide & adjust the nipple end of the t-couple to the "sweet spot" of the pilot flame, which is right at the blue flame tip. I've installed / retro'd hundreds of em and w/ little adjustments they all will line up & run fine.

[Ronnie D]

Looked in an old manual for Orbis & couldn't find much , but SIT came up & gave these guys for O.E.M. parts source.
I've never had any dealings w/ em.

https://www.fire-parts.com/products/sit-thermocouple

[hawg]

 Ronnie, I think, not sure, the SIT is the way the gas valve end attaches/works. The SIT valve requires a SIT fitting. Not 100% sure.

[Ronnie D]

Not sure what ya mean by gas valve attachment, but the thermocouple in pic. will fit ANY   standing pilot gas valve used for a residential/ light commercial application. You could swap it w/ the one in your hot water tank & it would work fine. Its 2 pieces of fused metal that creates 25 millvolts when heated & all valve thread ends are industry standard unless reverse or special applications, which doesn't apply in dis situation. If you have a d.c. multi meter , you can test the old one by using a lighter & alligator clips.

[hawg]

Thanks again Ronnie, I’m still learning. What happens if the wire lead from the thermocouple to the valve gets linked? Are they ruined?

[Ronnie D]

I think ya mean kinked ?
You can put an ohm meter from tip to tip & if resistance is above 35 Ω , It's weak. If it's infinite , the links broken & trash it

[Ronnie D]

If you do use the ohm meter trick & Ω value is high, try sanding the entire nipple  shaft &  tip ( pilot end ) w/ sandcloth or an emery board till it's shines. The thin layer of burnt crud adds resistance & is more than likely da problem. I do the same w/ all my buddy heaters every season.

[hawg]

I mean the wire or tube between the actual thermocouple end and the valve. I’ve never kinked one but always wondered.