FtL/fired too long error message. Restart or not?

[s6x]

I'm firing test tiles in my test kiln to cone 6, and at 2100f it got a FtL /Fired too long error message and then temperature rapidly decreased to 1900 before I decided to restart it.  it's now slowly trying to reach cone 6 temperature at 2232F again.   Will these test tiles be unusable now?  Or does it not really matter as long as it reaches the correct cone 6 temperature at some point?  even if it reaches that temperature twice?  or would accepting the 2100F render more accurate results??  Just trying to understand how this all works, so I know for next time.  

 I think I might have gotten the FtL message because I set the target temp at cooldown to 32F.   it says in the manual that  "programming a cooling segment target temperature that is below room temperature can trigger the FtL message".    Strange that it would give me the error message before I even got to that ramp hold segment.  But anyway, let me know if you have any advice should this happen again in the future.  

Edited March 25 by s6x

[Bill Kielb]

FTL message usually indicates not enough power to get to temp. Worn element(s), bad relay - some mechanical or electrical reason it cannot maintain a reasonable rate of heating at the end. On the test tile side, Orton says most of the important (flux) heat work work will be done in the last 200-250f degrees given a reasonable rate of rise during this period. If your kiln stops well short of that last 200-250 degrees then generally things can be restarted as if nothing significant happened. 

In your case, you are sort of close so restarting likely fine if you can make temp at a reasonable rate. If it stalls again though you are going to need to diagnose the problem and those tiles are likely half baked and depending on the stall temp can end up looking any number of ways. If you have witness cones in place then plus one - you will have an idea of how much heatwork you achieved. If virtually none, then repair the kiln and refine.

My guess is it stalled for a reason and It will stall again. My rule of thumb is if it stops 250f or more before it’s final temp it usually can be cooled and refired after repairs with it likely ending up looking / firing as normal. In effect no heatwork was done during the most important phase.

[oldlady]

question.   did i read that you are making test tiles and firing them to cone 6?     now that you have fired them, you must have learned that they should only go to bisque so they can absorb glaze in the same way you will working with actual pieces. 

bisque temps are a whole subject with many options and reasons for selecting the best cone for your clay and style of work.