How to fix E-1 or Err1

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How to fix E-1 or Err1

Possible Reasons for E-1 (or Err1)

NOTE: E- 1 errors read as "Err1" on controls manufactured before 2006


  • If you see an E-1 or Err1, then for some reason the kiln could not generate enough heat to counter the heat loss. If one of the elements or one of the circuits in the control fails while the kiln is at a high enough temperature, then it will probably display an Err8 code (which means temperature is falling when it should be rising)
  • Err1 or Err8 can mean either you need new elements or a new component in one of the circuits. A Paper Test, an Ohms Test and a Voltage test can tell you which it is. 
  • Non-standard elements from an unauthorized supplier have too much resistance, or you did not hook them up properly (leaving the jumper wire out of a J230 section will double the resistance in that circuit and only one of the two elements will be used. Always use a ohms meter to check the element and circuit ohms.)
  • Some or all of the elements may be worn out. You may notice slower and slower firing over time, with bisques still ok, no clicking at the top temperatures and uneven results. E- d codes are possible too.
  • Element(s) out- broken inside the kiln, look for damage or perform a paper test.
  • Element(s) out- a wire bringing power is burned off.
  • Element(s) out- the center relay is out. The kiln section's temp may noticeably lag behind at med/ high temperatures. Top or bottom relay failure usually gives an E- d

Voltage or Wiring Problems

  • If you recently changed locations, power supplies, elements, or did any repairs, then closely examine what changed between your last successful firing and this one. There may be some other issue besides bad elements or a bad component.
  • A new location can mean a 208 volt power supply rather than a 240 volt supply (about 25% less power).
  • Wrong voltage power- These cases are usually a school that has a 240 volt kiln. 99 out of 100 schools run on 208 volts not 240 volts.
  • In re-wiring the power supply you may not have used thick enough copper wire (line, conduit and connection points will be very hot).
  • If you rewire anything improperly or incorrectly the potential for anything from a blown breaker to just no power at all is possible. (Using wire with a temperature rating of less than 150°F can seriously limit the life of the circuitry and can be dangerous as well, especially when the wires are close to the kiln. Use a wire diagram and trace every wire to check yourself). You can buy high temperature wire from L&L.
  • Power cord is overheating in the outlet/ up against the side of the kiln or some other connection point is overheating, this can always be seen- will look overheated and will be hot when kiln has been on for a while. Voltage test near the elements will show this too.
  • Summertime voltage, or just poor voltage in general, can be from wrong sized wire or too long a run. This problem is compounded by longer and longer firings as elements prematurely age.
  • Are you running more than one kiln at the same time? This could be lowering your voltage.
  • The gauge of the hookup wire is not large enough which creates a voltage drop and reduces power to the kiln. See this link for more information.
  • How old are the wires that connect the elements to the relays? If they are older and have been pulled off and on the relay a few times then it could be generating a hot spot on the relay and making it fail causing the Err1. This normally happens when the kiln is at hotter temperatures.

Thermocouple Problems

  • Check out the thermocouples. When they wear out they often don't read accurately at high temperatures, which can produce an Error 1 code.
  • Thermocouples reading unevenly (from age or loading unevenly or too close to the thermocouple).
  • Different style thermocouples used in same kiln

Loading Issues

  • Loading may be uneven- try putting two elements between the bottom two shelves and add more mass to the upper areas in the kiln.
  • Loading may be too close to the thermocouples.

Other Possible Problems

  • DaVinci/ Handheld only- Check Handheld 14-pin connector for poor connection. Wiggle the connection point carefully while running the kiln and listen for relays to correspondingly go off and on as you wiggle it.
  • Lid/ Hinge out of adjustment- lid opens a bit in the front when hot.

Error 1 at Low Temperatures

Sometimes you will get an E-1 at a low temperature due to the confluence of several variables.

  1. The first possibility from is that the kiln's load is uneven relative to the element heating zones and their thermocouples. This especially if the bottom is loaded heavily compared to the top. Be sure the bottom shelf of the kiln is under the bottom element and up on at least 1/2" tall posts.  Then use 8" posts to place the next shelf high enough to allow two elements (or bottom 3 elements if your kiln has 3 elements in the bottom section) to shine into the bottom area of the kiln.
  2. The second possibility is that there is something too close to a thermocouple in one kiln section, but not in another. Try to keep everything at least 1" from a thermocouple.
  3. The third possibility is perhaps a result of the way the kiln acts normally at low temperatures. Because of the thermocouple protection tubes, a change in temperature does not affect the thermocouple in the tube for a few seconds. During that few seconds, until the change of temperature is felt by the thermocouple in the tube, the kiln continues to heat. Normally this matters very little. All it does is make the firing little jerky at first. It will rise a few degrees, wait for the set point, rise a few more degrees, wait, rise, wait etc.  The hotter it gets the more it rises and the less it waits.

It is rare for any one of these variables to cause E-1 by itself, but when these variables get together it is possible for the kiln to climb slower than 12 degrees per hour for 22 minutes while waiting for the set point to catch up at low temperatures- and that is where you can get E-1E-1 at a low temperature will sometimes be proceeded by one of the thermocouple readings lagging behind the others. Try to be sure about the loading and perhaps- if it is OK for the clay- try a Fast Bisque instead. Usually E-1 at low temperatures will not happen on faster programs because the kiln is spending more time heating and the set point is rising faster.

Additional Actions to Take

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.

  1. Check your voltage at the receptacle or at your fused disconnect box. Check voltage at your panel and where the kiln is connected. Check the voltage when the kiln is firing and when it is not firing.
  2. Make sure no other large electrical appliances such as a clothes dryer or electric oven are on when you are operating your kiln.
  3. Find out from your local utility company when the end of the peak period of electrical use is.
  4. Check to see what the wire size of your circuit is. If it is very far (more than 50 feet) from your main circuit box then the wire size might need to be higher.

  • 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. Make sure power cord is plugged in.
  2. Reseat the plug. Pull it out of the receptacle and put it back it. This will reseat the connections.
  3. Also, sometimes the female socket and/or the male spades get oxidized (which can resist the flow of electricity). Reseating them can disturb this oxide layer.
  4. When you do this examine the plugs for any signs of burning or overheating. If the spades look oxidized you can rub them with steel wool to shine them.
  5. Make sure the plug is held firmly and that the springs inside the receptacle seem to be working.
  6. Look for any damage on the cord itself.
  7. Make sure the cord is not touching the kiln case.

CAUTION: This test should only be done by an experienced person familiar with electricity and its dangers.

  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. Make sure the circuit breaker or fused disconnect switch is turned on.
  2. If you have a circuit breaker flip it back and forth to make sure that it is really on. Some circuit breakers, if they have tripped, will not be obviously in a tripped position. By flipping it back and forth you will reset the circuit breaker.
  3. Check voltage of your power supply at the receptacle using your multi-meter set to the next highest AC voltage above 240 (typically this will be 600 volts but may be 250)
  4. Check fuses for voltage continuity. You can do this with your multi-meter.
  5. Make sure fuses or circuit breaker are/is the proper amperage and type. See your wiring diagram for the required fuse type.

CAUTION: This test should only be done by an experienced person familiar with electricity.

  1. Make sure peepholes are plugged with peephole plugs.
  2. Make sure hole for vent is proper. Check Vent-Sure instructions for proper hole sizes.
  3. If you are using a different brand of vent make sure it is the appropriate size for the kiln. Check with the vent manufacturer and tell them how many cubic feet are in the kiln.
  4. If the lid or bottom is cracked check to see if it seems to leaking much heat at high temperatures. Patch or replace if extreme.
  1. Plug element holes if they are too large.
  2. Lightly stuff non-RCF ceramic fiber in the element holes from inside the kiln using a sharp tool like a very small screw driver.
  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.