1984 Cress 27x-p not hitting temp, please advise!

[ChelseaRae]

Hi there, 

Thanks in advance for any tips or advice! I have a ‘84 cress kiln 27xp.  On my last 2 firings the kiln has been running longer and not hitting temperature (cone 04 and cone 5).  I had a kiln tech come out and look at the kiln and was told that the elements were reading as ~49 and that I wouldn’t need to replace them until they read at ~45.  I had a relay replaced which fixed the problem of the thumbwheel not turning during firing.  Since the repair, the plunger will not stay plunged (not sure if this is the right language to describe that) and the kiln tech told me to quickly move the timer between 10 hr mark and max time at 20hr so that the latch bounces and removes any debris that may be trapped in there.  This worked when I tried it out with the tech on the phone and without kiln loaded (had to unload kiln to be able to take out the bar from the sitter) and when I loaded kiln again and went to turn it on, had to unload again.. do the same procedure and it turned on.  I am wondering if anyone has any ideas of a solution on this.  

Also, I am not sure why the kiln won’t even hit temp during bisque firing.. this is the first time that has ever happened (and since repair). It ran for 10 hours, shut off with timer and the bar never melted to trigger auto shut off.  I am wondering if anyone has suggestions on this that could help.  My witness cones varied across the shelves with one seeming to over fire (top shelf which was at about 2/3 height at the inside of the kiln).  The middle shelf (mostly had plates on it, things of that nature) did not hit temp, and the bottom shelf (not sure.. I forgot a witness cone).  

I am wondering if how I load the kiln would significantly change things so that the kiln wouldn’t auto shut off.  The last firing was a lighter load.  I am also wondering if I should consider adding more time on the timer, loading with more space between shelves, and if firing on a faster setting would help... or if I am looking at costly repairs.  Pray to the kiln gods for me.  All help or suggestions are appreciated.  Thank you.  

[Sorcery]

No downdraft vent?

So far, more timer time makes the most sense.

 

Sorce

[ChelseaRae]

Thanks for your comment, everything helps. I do not have a vent installed.  However, when I fire it is in a well ventilated space- its in a detached garage with airflow from a window/door/garage door that is partially opened.

My timer is functional- it shut off with a timer in the last firing.  I am concerned because it usually does not take 10 hours to fire and not hit temp.  It measured 10 hours on kiln timer and in real time.  

I am stumped and think maybe its an elements issue after all.