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It was a safety thing -- it (understandably!) didn't like the debris in the valves. Unpacked the kiln this morning -- beautiful firing and in the shortest firing timeframe reflecting the original manual. So happy a potter all round!

Thank you! Yep all correct, when the kiln had cooled I saw debris had fallen into the burners (I'd covered them but not well enough it seems!) gave it a good clean and now firing smoothly today but requires double the pressure again. I have the manual now kindly given by a member here and the pressure increase matches the sample firing given in the manual - just trying to get my head around why it needed less gas before. I think the kiln is now well-sealed and repaired, so is there less airflow? The dampers are adjusted at the top of the kiln across the top vent. I will take pictures.

Good morning, almost a year and a half since I started this thread and the kiln has been firing consistently beautifully until this week. My kiln roof collapsed (the lining inside) last week (it had been on its last legs for a while) and we replaced it at the weekend, replicating the same fitting and materials as before. BUT my firing on Monday suddenly needed almost double the pressure to get to the top temp (150mb was enough to reach the top temp before -- this time it took to 250mb), today I started the kiln as normal at 6 this morning but still needed double the pressure to get the same temp rise and then about 2 hours into the firing the kiln started turning itself off and reigniting say about every 10/15mins. I've turned the whole system off, checked the valves were clear (as much as I could from the under and side I'm waiting for the kiln to cool to check no debris has fallen from inside the kiln) and swapped the bottles over to full tanks (although the other bottles still had half tanks). Restarted the kiln and again every 10/15mins the kiln shuts off and reignites. I've got in touch with my gas plumber but just reaching out to see if anyone has had the same problem/has any ideas about what's going on?

Hi Neil, I did get a cold spot in the front left, is there anything I can do to counteract this?

The regulator -- the manual specifies up to 300mb so 30mb was going to be tricky to get to top temp I think...

Thank you so much for all your help, I managed to find someone who has the same kiln as me and the manual!! So the correct regulator is in and she is firing beautifully. @Bill Kielb thank you for your detailed firing tips I followed it today and looking forward to opening the results on Saturday! Thank you also @Mark C. for all your help!

I did this! A 0.85mm drill bit fit into the orifice of the gas burner

Yes exactly, was planning on using the strips of fiber as dampers but also have kiln bricks

I hadnt reached 850/900 which is when I used to start using dampers in my old kilns. Would you recommend doing before then?

The previous owner slid fire bricks/or kiln shelves over these top slots for reduction, half way either side

Some more images.. not sure if they're helpful!

Sorry not to have got the orifice sizes to you yet, don't have small enough drill bits and couldnt get them undone but I'm sure the plumber tomorrow will have something he can measure them for me! No damper at back or in flue, its at the top previous owner slid fire bricks over the chimney slots for reduction, Thank you, really hope I can get it going Chloé

Hi, thank you! Sorry will get back to you re orifice size, I don't know how to get to the burners to measure it. Has a damper ontop its a updraft, I'll attach a pictures, yes I have a storm cap which I put on when not firing. The shed is just for the kiln and the door stays open during the firing. The clesse changeover has a 37mbar restrictor on it - is that an issue? How do I calculate the mbar/bar I need? I think my plumber should have got me the 750mbar changeover? Many thanks, Chloé

Hiya thank you! The hood and bars between the kiln body came with the kiln/are part of the model. Will get back to you re orifice size - I dont know how to move the burners to measure the size will ask the plumber coming on Wednesday. And I dont have contact with the previous owner who converted it for previous orifice size I'm afraid. I attach further pictures, the clesse changeover has a 37mbar restrictor on it - is that an issue? How do I calculate the mbar/bar I need? I really appreciate your help thank you,

I bought a J9 Laser Gas Kiln last year and finally got it installed, but I can't get it to reach above about 750˚C. It rises over 6.5hrs to reach my maximum 35 Mbar at 570˚C and then crawls to 750˚C at 9hrs. I thought too much gas needed more air, so I've lowered the pressure, but the temperature quickly started to drop again. The kiln was converted from Natural Gas to LPG; its internal dimensions are 52cmsq 80cm tall. With 4 burners, it runs off 4x47kg, which has a Clesse Automatic ChangeOver Kit has a hood and flue. It came with only a couple of pages in the manual, and the lady before me hadn't fired it before. Before her, the previous owner converted it to gas (and my plumber has checked it all over and connected it up). But we can't figure out why it's not reaching higher temperatures... I have fired 3 different gas kilns regularly for the past 6 years, but all were installed by others, and I booked to use them, this is my first own gas kiln, and I was so excited to be self-sufficient. I have been using my previous firing schedules, but this is performing miles behind. Any help would be hugely appreciated. I have a deadline for an exhibition looming ever closer I'm sure I must be doing something wrong, I will attach pics of the set-up, My plumber thinks that the interior needs replacing, it has cracked walls, and the front door padding has sagged, but it still does seal. Or he said he could look into making the burners orfice larger.