I have a Reznor F100 ser# ANK31k5n65696, Natural gas, manufactured Nov. 1988. Since that time it may have run 90 days total. I have tested the transformer, it appears the 120 side is bad. I have pulled the three sensors so that they can be tested (once I know how)

In researching a new transformer in Reznors part cat. At:

https://www.rezspec.com/index.php?pa...0012&mod_files[currpos]=000000000054&mod_search[text]=P-F%2FB&mod_search[skipsearch]=true

Then you ([F]If you want to see the parts I am talking about --- Middle of page ) select:
P-F_B.pdf... Replacement Parts - Model Series: B, BE, F, FE Unit Heaters

On page 19, They reference "F 25-400 Single-Stage, March-Lit Pilot" uses a "115/1/60, 12VA, Basler #BE141615-RAD Part No. 131988 replaces part 102706"
OR
"f 75-400 Two-Stage, Match-Lit Pilot" uses a" 115/1/60, 20VA, Basler #BE141620-RAD, 132204, replaces part 102709".
Since the part number on the existing transformer - Reznor 96346-class 2 60hz, TE121224-B11, pri bk-yw120v, sec 25v 12va, do not match any of the choices, am I correct in picking: 115 1 60,12va, Basler #BE141615-RAD ?

Having replaced the gas valve and pilot assembly ([F]the starting problem being pilot would not stay lit) to no avail, as I see it, there are only three other parts left to replace: (All on page 18) the ECO device that goes to the valve near the pilot gas supply, - replacement part #82414; limit control, auto reset - replacement part #45602; and fan control assembly - replacement part #123976(the old numbers don't match but it does say 150-35f)
Is there a way to test these 3 items so I can put in one order and be done? I built a scaffolding over the chest freezer a couple weeks ago to get to the control side of furnace(to old, to fat, to ridged to hang sideways from ladder) I am in the better half's way and she is starting ask if I am ever going to get done working on that piece of junk!
Thanks Terry

If I`m looking at the right one,, it looks like a standard 120/24 volt step down transformer which is universal except maybe for the mounting base ,which can be altered to work,, these can be bought at any heating /cooling parts house,,

I have 2 model F heaters. I found shorting VCO device with a cliplead allows pilot to stay lit.
Danny Sadler