How to fix E-d or Errd

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  • The Knowledgebase is organized into a series of questions and answers having to do mostly with technical troubleshooting and understanding of kilns.
  • Although we write this for our own kilns many of these articles apply to other makes - although L&L takes no responsibility for that.
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How to fix E-d or Errd

Note: E- d errors read as "Errd" on controls manufactured before 2006

Basic Problem

  1. In general E- d or Errd means that one of the thermocouples' temperatures is 50°F above traveling set point.
  2. The basic cause of this is some condition that is causing the heat of the elements from not getting to the thermocouple tip or some sort of erroneous thermocouple reading.
  3. This often happens during a first firing in an unloaded kiln. The first thing to do is to fire the kiln with shelves evenly loaded in the kiln (avoid putting the shelves directly in front of an element or allowing a shelf to touch a thermocouple.
  4. If all else fails just turn off the Error Codes.

Potential Causes and Solutions

Loading and firing Issues

  1. Loading may be uneven: Try making sure two elements are exposed between the bottom two shelves so that more heat is put in the bottom.
  2. Load may be too close to or is touching the thermocouples. This would shield the thermocouple from the heat of the kiln. Allow almost an inch between everything for thermal expansion. Fix and re-fire the kiln.
  3. Center zone is too hot.

Power Issues

  1. Element(s) out: They could be broken inside the kiln. Look for damage or do a paper test. Test ohms.
  2. Element(s) out: Wire bringing it power may be burned off.
  3. Relay out: A kiln section’s temperature is noticeably lagging behind at medium to high temperatures. Check relay.
  4. Check to make sure relays are connected to the proper outputs on the control board.
  5. There is a bad connection point somewhere and it is overheating causing a voltage and power loss to the kiln. This will become more of a possibility as the kiln ages. Examine all points carefully for melting, corrosion, discoloration and/or bad smell. This can usually be seen. It will look overheated. 
  6. 3 phase kiln hooked up to 1 phase with a neutral on the center leg. This would not provide proper voltage to some of the elements.

Thermocouple Issues

  1. Thermocouples are reading unevenly (from age, loading unevenly or loading too close to the thermocouple). Check thermocouples.
  2. Different style thermocouples were used in the same kiln. For instance you could have a metallic sheathed thermocouple and an exposed 8 gauge thermocouple.
  3.  A thermocouple extension wire has melted against the kiln case (the thermocouple extension wire can melt and send erratic signals to the DynaTrol). The wire extension must be replaced.
  4. Thermocouples are not fully inserted into the kiln. They should be in at least 1".
  5. A thermocouple is about to fail. Perform a physical inspection if possible, or just re-start the kiln and monitor it carefully.
  6. One or more of the thermocouples is bottoming out in the thermocouple protection tube. This could give you very different readings in the various thermocouples which would give you an Error D. To solve this put a washer on the mounting screws between the ceramic washers - you only need to pull back the thermocouple a 1/8" or so.
  7. Debris in the thermocouple protection tube could also be causing different readings in the various thermocouples. Remove them and dump out any debre.
  8. Make sure thermocouples are connected to the proper inputs on the control.
  9. There is noise in the thermocouple circuit.

Kiln Assembly Issues

  1. Easy-Fire or eQuad-Pro kiln is reassembled incorrectly: backwards thermocouple wires at thermocouple or at terminal strip.  Power wires not connected in right order on terminal strip or on relays.
  2. Jupiter and DaVinci Kilns: If the kiln was just re-assembled double-check that the kiln sections are plugged into their appropriate receptacles and the thermocouples are in the proper zones:
    1. Two section kilns: Top ring is in #1 receptacle on the control, bottom is in #2. Top ring gets TC1 bottom ring gets TC2.
    2. Three section kilns: Top is in #1 receptacle, middle is in #2, bottom is in #3. Top ring gets TC1, middle ring gets TC2, bottom ring gets TC3.
    3. Four section kilns: Top is in #1 receptacle, next section down is in #3, next is in #4, the bottom is in #5 (the cords and numbers go 1,2,3,4, but the second receptacle down on the control box is skipped; there are five circuits on the control, but only four sections. The top ring gets TC1. Either the upper-middle or the lower-middle section can have TC2 in it. The bottom ring gets TC3. All five circuit controls have the center three circuits tied into TC2. Therefore, skipping #2 receptacle with the four ring kilns would be the same as skipping the #3 or the #4 receptacle. TC1 must always be in the top section and TC3 must always be in the bottom section. TC2 can be in either of the middle sections.
    4. Five section kilns: Top is in #1 receptacle, upper middle is in #2, middle is in #3, bottom-middle is in #4, bottom is in #5 receptacle. The top ring has TC1 in it. The middle ring has TC2 in it (receptacles #2,#3,#4 go on and off together), the bottom ring has TC3 in it.
  3. DaVinci Handheld Control: Check Handheld 14-pin connector for poor connection. Wiggle carefully while running, etc.

Other Issues

  1. You were firing with the lid open and you got Errd either while the lid was open or right after you closed it. For drying with the lid open, only about two inches is needed to adequately vent off water vapor. This is plenty if all the peep holes are open. The DynaTrol will attempt to compensate for the heat loss, and it usually can. The trouble may happen when you close the lid. The elements in the top of the kiln are already much hotter than the ones nearer the bottom due to their need to compensate for the heat loss from the top. When you close the lid it can take as long as eight seconds for the DynaTrol to respond to the rise in temperature in the top of the kiln, and shut off those elements. This can quickly cause an uneven temperature in the kiln, which will usually result in Errd (possibly an Err2 in a smaller kiln -Err2 is when the entire kiln temperature is more than 50°F over the hold time's temperature for longer than 18 seconds).
  2. There was a lot of air being exhausted from your kiln when Errd appeared. If a vent system pulls too much air from just one point in the kiln, say, to down-ramp the load very quickly to a lower hold time for crystal formation, an uneven temperature can result. The firing will go slowly as it will be difficult to compensate for the heat loss; eventually, however, the Errd (or Err1) can appear. 

Additional Actions to Take

Use cone packs in all sections (top, center, bottom) of the kiln and keep records of what happens.

  1. Unplug kiln.
  2. Remove or hinge open the control box.
  3. Remove the Thermocouple Lead Wire from the Thermocouple.
  4. Unscrew the Thermocouple from the kiln.
  5. Remove Thermocouple.
  6. Install a new Thermocouple and screw in place.
  7. Replace Thermocouple Lead Wire and tighten. Be sure to get red matched to the MINUS (Negative) sign and the Yellow matched to the PLUS (Positive) sign.

See this video:

Running a paper test is a great way to troubleshoot your kiln. With just some scraps of paper and 5 minutes you can determine if you have any elements or relays that need replacing.

Despite it's usefulness, the paper test cannot compare to the information that you can get from a multimeter. It will only point you in the direction of a problem, not pinpoint it.

The Paper Test

  1. Start by folding up small strips of paper. You will need one paper per element in the kiln that you want to test.
  2. Turn off the kiln and unplug it (or at least shut it off at the circuit breaker/fused disconnect).
  3. Insert the paper scraps in between the coils of each element. It does not matter where along the element.
  4. Plug-in and turn on the kiln.
  5. Program for Fast Glaze to any cone (or turn manual switches on high).
  6. With the lid open, watch the paper scraps for smoking. (Do NOT reach into the kiln while it is on. Contact with the elements could cause electrocution and/or burns).
  7. After approximately 2 minutes, the paper should start to smoke. Wait another minute or so to give them all a chance to burn.
  8. Turn off the kiln and unplug it (or at least shut it off at the circuit breaker/fused disconnect).
  9. Use pliers, tweezers, etc. to remove the paper from the elements as they will still be very hot. Make sure to note which pieces burned and which, if any, did not.
  10. Vacuum or simply blow out any remaining ashes in the element holders.


Once you have your results, you can start to draw some conclusions. We will look at one section at a time. These are some potential results and causes. Keep in mind you might have any combination of these issues.

If the paper is not burnt in one element in a ring:

  1. The element is burnt out/broken and needs to be replaced.
  2. Your elements are wired incorrectly at the element terminal block.

If the paper is not burnt in all (2 or 3) elements in a ring:

  1. All elements in the ring are burnt out/broken and need replacing.
  2. Your relay for that section is burnt out and not working.
  3. One (or more) of the power wires to that ring is burnt or disconnected.
  4. Your controller is not sending the proper output to the relay. Test the controller.

Resistance and Error 1

  • The most common cause of kiln slowdown, E-1 messages, and failure to reach temperature is element wear. As your elements age they generally increase in electrical resistance.
  • When resistance, measured in Ohms, increases, both Watts and Amperes (amount of power) will decrease, assuming Voltage remains constant. If you don't have enough power, your kiln will fire slowly and might not even reach the desired temperature.

What does this mean?

  • Using resistance, we can tell exactly how much power your kiln has lost over the course of your element's life.
  • For example on an e23T that uses 240V, a brand new kiln section would read about 14.5 ohms. If you measured this same kiln section after many cone 6 firings and the reading was 16.5 Ohms, you would know that this section of elements has lost approximately 14% of it's power (16.5/14.5=1.138, or close to 14%).
  • A very general rule of thumb is that most people will typically begin to notice some slowdown once you've lost more than 10% of your power.
  • It will certainly vary based on the kiln you have, your voltage, as the types of firing you do. People only doing low fire work will continue to get by on lower power than those needing to go to higher temperatures (cone 6).


In these series' of kilns a piggy-backed control panel covers up the element terminals.

  1. Turn the power to the kiln completely OFF and unplug it if possible. If it is direct wired, then you should at least turn off all power at the disconnect switch or circuit breaker.
  2. Open the outermost control panel by unscrewing it either from the element cover box in the case of Easy-Fire, eQuad Pro, School Master and Liberty Belle kilns or from the kiln body in the case of Doll kilns.
  3. Once you open up that control panel you will see the element power wire terminal strip. See the picture. It will have numbered wires coming from the element terminal blocks and wires connecting to the power relays. There are two wires per kiln section/ring, so numbers 1 & 2 are for the top section, 3 & 4 for the middle, and 5 & 6 for the bottom section on a three ring kiln.
  4. Set your multimeter to Ohms (Omega symbol Ω) and using your testing leads, place one in between the two tabs/terminals w/ #1 wires connected. There is a small circular divot that the lead fits into (see picture). Put the other lead on terminal #2 and make note of the reading. Repeat the process for 3 & 4 and then for 5 & 6. Remember that each pair of wires represents one section.
  5. Compare your readings to those on the wiring diagram in your instruction manual. Keep in mind that the ohms on the wiring diagram are per ELEMENT while your reading will be per SECTION. See above for more info on understanding the readings.



In these series' of kilns, the control panel is separated from the kiln body and the element terminals are connected to the controls via external jumper cords or plugs.

  1. Turn the power to the kiln completely OFF and unplug it if possible. If it is direct wired, then you should at least turn off all power at the disconnect switch or circuit breaker.
  2. Unplug the first jumper cord from the control panel.
  3. Set your multimeter to Ohms (Omega symbol Ω) and using your testing leads, place one lead on each of the "hot" prongs. They will be the flat ones.
  4. Make note of the reading and move on to the next one.
  5. Compare your readings to those on the wiring diagram in your instruction manual. Keep in mind that the ohms on the wiring diagram are per ELEMENT while your reading will be per SECTION. See above for more info on understanding the readings.


See this tutorial on how to use a multimeter.

Ohms Per ELEMENT VS Ohms per SECTION (or Circuit).

  • How you figure out the section ohms depends on whether the elements are wired in Parallel or Series.
  • Most kilns are wired in Parallel except for JD230V and most 18" kilns like the e18T.
  • For a parallel kiln you take the per element ohms listed on your wiring diagram and divide by the number of elements per section.

Example #1 (2 Elements in Parallel): e23T 240V 1 Phase: Elements are 28.9 Ohms each. Divide by two because they are in parallel and you will get a reading of 14.5 Ohms per section.

    Parallel element connection for a kiln with two elements

    Example #2 (2 Elements in Series): e18S 240V 1 Phase: Elements are 9.6 Ohms each. Multiply by two because they are in series and you will get a reading of 19.2 Ohms per section.

    Series element connection for a kiln with two elements

    Example #3 (3 Elements in Parallel): JD2927 240V 1 Phase: Elements are 36.5 Ohms each. Divide by three because they are in parallel and you will get a reading of 12.3 Ohms per section.

    Parallel element connection for a kiln with three elements

    Example #4(3 Elements in Series): Doll DLH11-DBX 240V 1 Phase: Elements are 6.6 Ohms each. Multiply by three because they are in series and you will get a reading of 19.8 Ohms per section.

    Series element connection for a kiln with three elements

  1. Empty the kiln.
  2. Turn kiln on using a fast program such as FAST GLAZE (USr3) until elements are red.
  3. Open the door carefully and check if each of the elements are glowing with approximately the same brightness.
  4. This is an approximate method. The best thing to do is check the ohms on each element or circuit.

CAUTION: The power does not turn off when the lid is opened. Do NOT put your hand inside the kiln while it is on.

  • Power relays are one of the most important components in your kiln. They execute the will of the computer controller, giving power to the elements only when requested. These power relays are also mechanical switches which will wear out over time. Worn out relays can be the cause of slow or incomplete firings, error codes (E-1, E-d), etc. Other more obvious signs of relay failure are if a zone is lagging behind in temperature considerably or if you notice an entire ring of elements not heating/glowing. 
  • The surest way to test your relays is by using a multimeter to check input, output, and signal voltage. If you do not have access to a multimeter you can run a paper test, which will give you some indication of whether or not you have a relay out.


  1. One way to check the relays (or bad elements) is to check the temperatures of each zone by pressing "1", "2" and "3" in sequence and recording the temperatures of each thermocouple at intervals over the length of the firing. If one zone is consistently firing at a lower temperature then you probably have either burned out elements or a bad relay.
  2. If the relay does not make a soft clicking noise when the kiln is turned on try turning the kiln off and on and then restarting the program.
  3. Remove panel.
  4. Set your multi-meter the approximately 24 volts AC. Check the voltage coming into the coil of the Power Relay. You can tell which wires these are because they will be the small wires coming from the control. This test will tell you if you are getting power to the relay coil which actuates the relay. Unless the relay is actuated by the control you will get no output from the power side of the relay.
  5. With panel plugged in and firing check output from Power Relay with your digital multi-meter. The meter should be set to the next highest voltage above 240 volts AC. Output should be approximately the rated voltage of the kiln when it is supposed to be calling for power to the elements.

CAUTION: LIVE ELECTRICITY IS INVOLVED WITH SOME OF THESE TESTS. This test should only be done by an experienced person familiar with electricity.

  1. Carefully examine thermocouple tip. This is the exposed welded joint at the end of the thermocouple that is not covered up by the ceramic tube.
  2. To do this you will have to remove the thermocouple from its protection tube (if it is a kiln that has one of our protection tubes). You can do this with the kiln disconnected from power.
  3. Look for corrosion - especially if it severe. These thermocouple tips will oxidize and otherwise corrode over time. That is normal. There is some point, however, at which the corrosion affects the ability of the tip to work (thermocouples work by generating a small voltage at the tip caused by two different metals reacting to each other).
  4. Corroded thermocouple tip

  5. Make sure the two wires are securely joined. One of the things that can cause an intermittent problem is a bad weld. If the two wires touch each other (even if they are not welded) they may work temporarily. However, if the weld is not secure then the wires could separate when the kiln heats up and cause an intermittent failure.
  6. If the thermocouple tip looks healthy then test the control board.

  1. Unplug kiln or turn off circuit breaker if the kiln is wired direct to your power supply. If you can not physically be sure the power is disconnected (for instance is you see that the cord is unplugged you KNOW there is no power coming into the kiln) then check the voltage at the power connection pluck with your multi-meter.
  2. Open up the control panel. This will be a little different on each kiln series.
  3. Remove or open the panels that cover the element connections.
  4. Look at internal wiring.
  5. Images burned wires in a kiln

  6. Check the tightness of all connections. Do this by wiggling the connector to make sure nothing is loose.
  7. Make sure all wires are connected to their proper connection point. You may have to compare the kiln to the wiring diagram to be sure of this. This step would be particularly important if a wire has come loose.
  8. Specifically look at wires going from power connection block to the on/off switch, then to the control fuse, and finally to the control transformer.
  9. Make sure all wires inside control panel are connected.
  10. Look for any burned spots or deteriorating wire.
  11. Look for any short circuits. This might be caused by a wire losing its insulation and touching another component for instance. Typically if there are any short circuits there will be some evidence of a burn on the metal the wire touched.
  12. Look for dirt or foreign material. Some material can be an electrical conductor and could cause a short circuit. Clean out any dirt.
  13. Pull off and reseat all spade connector connections of power wires to remove oxides and ensure good connection.

CAUTION: Turn power off to kiln from the circuit breaker or unplug the kiln.

Fix lid seal if a bright red glow is visible around the seal when kiln is operating and/or excessive heat loss can be felt around seal.

  1. Rub seal high points down with sandpaper until no more than 1/16 of an inch gap is found at any point along seal.
  2. Check for unevenness in the gap that will cause an excessive heat loss.
  3. Replace lid if it is excessively cracked or worn or has holes in it. Replace lid.
  1. If uneven firing occurs persistently, distribute your load weight more evenly throughout the kiln or to match the firing characteristics of the kiln.
  2. If elements typically fire hot at the top of the kiln put more weight in the top to absorb that heat, and vice versa.
  3. The bottom shelf should be at least 1/2" to 1" above the floor of the kiln.
  4. Badly distributed load weight can also affect the firing rate of the kiln and lead to Error 1.

TIP: The longer square posts can be laid down on their sides to get a perfect amount of space under the bottom shelf.