Owning a kiln is a little bit like owning a car. With mindful operation and a little bit of routine maintenance, your kiln should last for decades! Proper kiln maintenance ensures your kiln remains safe and operational during that time.
The good news is that kiln maintenance is much simpler (and less expensive!) than maintaining your car. While a car has a gazillion different parts that will eventually need to be replaced, kilns have far fewer points of potential failure. And while it can be a good idea to occasionally enlist the help of an electrician or a kiln engineer (especially during installation), most kiln operators will be able to perform regular kiln maintenance by themselves!
Better yet, today’s programmable digital kiln controllers like TAP Controllers by SDS Industries include advanced diagnostics features and preventative maintenance alerts, so that you know when it’s time to replace kiln elements, thermocouples, and relays. That way, you’re able to maintain optimal performance without having to worry about your kiln conking out on you mid-project!
Routine Maintenance: Component Replacement
Just like with cars, there are certain kiln components that will wear down over time and will need to be replaced on a regular basis, so we’ll start with those first. These components include:
- Thermocouples: Thermocouples – the probe that measures the temperature of your kiln – are regularly subjected to high temperatures. Over time, thermocouples become corroded and start crumbling at the tip and will no longer be able to accurately record temperature. You’ll need to replace your thermocouples on a regular basis – typically every 30 to 50 firings for Type K thermocouples.
- Kiln Elements: Elements are the metal coils that line the inside of your kiln and heat up when they receive electric current. Over time, kiln elements become corroded and their resistance increases – meaning that they begin to become less efficient and require more electric current to heat your kiln. The lifespan of kiln elements can range anywhere from 1 to 5 years. Their lifespan depends largely on the type of kiln you’re using, the temperatures you regularly fire to, as well as firing frequency and duration.
- Mechanical Kiln Relays: Kiln relays regulate the power to the elements of your kiln, allowing them to heat up or cool down. Mechanical relays, which come standard on most kilns, are subject to failure after around 200,000 cycles and will need to be replaced every 12-24 months. Alternatively, investing in solid-state relays can reduce kiln maintenance costs, since those relays last much, much longer – possibly over 1000 years! (TAP Kiln Controllers are compatible with both types of relays.)
Replacing these components is an inevitable part of kiln maintenance. TAP Kiln Controllers calculate health and life expectancy for each of these components based on user defined thresholds, letting you know when it’s time to replace each component to maintain optimal kiln performance.
Regular Inspection of Other Kiln Components
Other kiln components that may require replacement include kiln bricks, kiln lids, electrical wires, and your kiln controller. However, there are steps you can take to monitor and prolong the lifespan for all of these components:
- For kiln bricks, be careful when moving your kiln or when placing or removing objects from your kiln. Regularly visually inspect the interior of your kiln. Kiln bricks will need to be replaced when they’re no longer able to properly support kiln elements or when significant chunks of kiln bricks are missing, affecting the thermal efficiency of your kiln.
- For kiln lids, be mindful when opening and closing your kiln to prevent denting or damaging the lid. Do not lean on your kiln or use it as a shelf for storing objects.
- Regularly inspect electrical wires for discoloration, brittleness, or corrosion. Immediately replace these components if necessary.
- For kiln controllers, make sure they are properly installed and regularly clean your screen to keep it free of debris.
TAP Kiln Controllers give users a detailed error log that helps them identify component failure. For a breakdown of error messages and troubleshooting steps, check out p. 12 of the TAP II Controller User Manual.
Kiln Maintenance: Installation
Ben Franklin once said, “An ounce of prevention is worth a pound of cure.” This is definitely true when it comes to kiln maintenance. Proper installation will prevent a ton of potential problems down the line.
Below are a few principles for kiln installation that will prolong the life of your kiln:
- Select a space with adequate clearance and proper surfaces. Heat is a common cause of kiln component failure (or worse!). When installing your kiln, make sure your kiln has at least 18” of clearance of clearance from non-combustible surfaces and 36” from combustible surfaces. Ensure the kiln is installed on a level surface that’s non-combustible and able to withstand high temperatures.
- Install your kiln in a dry area. Water and electricity don’t mix! Installing your kiln in a dry area prevents shorts and surges and protects your kiln from corrosion, which will significantly reduce the life of your kiln components.
- Follow manufacturer guidelines for installation. When you purchase your kiln, you should receive manufacturer guidelines for installation and kiln safety. Make sure to adhere to these closely when installing your kiln. If you purchase a used kiln, contact the manufacturer for installation guidelines.
- Get any electrical work done by a qualified electrician. At home kilns, especially larger ones, utilize a lot of electricity, so it’s important to make sure that you use a dedicated circuit with a properly rated power outlet and never use an extension cord. Enlisting the help of a certified electrician during installation helps reduce the likelihood of kiln maintenance problems down the road.
- Make sure thermocouples are properly installed. Thermocouples help your automatic kiln controller precisely regulate the temperature of your kiln. However, thermocouples will only give you accurate temperature readings if they’re properly installed! Thermocouples should be inserted an inch or two into the interior of your kiln and should have at least 1″ clearance from any shelves, components, or any materials you place inside your kiln.
- For DIY kiln builds, make sure relays are properly installed. Kiln relays ensure the safety of your kiln by cutting power to the elements if the kiln gets too hot. For DIY kiln or oven builds, it’s important to choose the right type of relay; for instance, solid-state relays will have far more longevity and reliability than mechanical relays. But it’s even more important to make sure that relays are properly rated and installed. Additionally, you can invest in a safety controller to add redundancy if one relay fails.
- Don’t store your kiln outside. Since indoor kiln installation for ceramics and glazing requires proper ventilation, it might be tempting to keep your kiln outside. We strongly, strongly advise against that. Exposure to the elements will reduce the lifespan of your kiln and all of its components.
Kiln Maintenance Tips Before, During, and After Firing
While proper installation and regularly replacing necessary components can prevent a host of kiln maintenance issues, there are also steps you can take before, during, and after firing to prolong the life of your kiln.
Below is a list of tips for kiln care and maintenance:
- Regularly clean your kiln. Debris, dust, and glazes in the interior of your kiln can reduce element efficiency, ultimately reducing their lifespan. Carefully dusting around the element grooves and regularly vacuuming your kiln’s interior helps prevent this. Just be careful not to damage the elements or the surrounding brick! If melted glaze gets on your kiln brick, make sure to gently scrape it off to avoid it absorbing into the kiln brick. You can also use kiln wash to minimize potential damage from dripping glaze (just make sure not to get it on the kiln’s elements!). Additionally, you should only clean your kiln when it is powered off to avoid causing electrostatic discharge if you accidentally hit the thermocouple and other mishaps.
- Keep your lid closed between firings. Leaving your kiln’s lid open leaves it susceptible to dust, debris, or wildlife getting in (yikes!). Make sure to keep your lid closed when you’re not using the kiln.
- Do not lean on your kiln. Leaning on your kiln can cause dents or stress fractures, reducing its efficiency.
- Don’t use your kiln for storage. Storing items in your kiln can easily damage the bricks or elements of your kiln.
- Be careful opening and closing your kiln. Be gentle opening and closing the lid of your kiln to avoid damaging the lid or the top-edge of your kiln.
- Don’t open the kiln for prolonged periods when it’s still hot. While it may be necessary to occasionally open your kiln to monitor the status of your work during firing, prolonged exposure to abrupt changes in temperature can cause cracks and fractures in your kiln brick.
- Regularly inspect kiln elements. Regularly visually inspect your kiln’s elements for debris buildup or corrosion. Occasionally, kiln elements may become dislodged from the grooves in the brickwork and may need to be repositioned. Additionally, you can use a multimeter to test their resistance. Once they exceed 10% of the recommended resistance in your kiln’s user manual, it’s time for them to be replaced.
- Invest in a safety relay controller. The biggest threat to your kiln’s lifespan (as well as your safety and the welfare of your household and personal property) is too much temperature. Occasionally relays fail. If they fail in the closed position, your kiln will keep heating up indefinitely. This is no bueno! Investing in a redundant safety relay controller like TAP Monitor ensures that your kiln safely shuts off in case of relay failure.
- Regularly replace all necessary components. Your thermocouple, kiln elements, and kiln relays will all need to be replaced at regular intervals. Make sure to always adhere to manufacturer recommendations for each component – and consider using a kiln controller like TAP that’s capable of tracking component usage against manufacturer specs to let you know exactly when it’s time to replace components.
How Your Kiln Controller Can Help with Kiln Maintenance
Wouldn’t it be nice if your kiln controller could tell you when it was time to swap out your relays, elements, and thermocouples?
TAP Kiln Controllers can do this automatically through the TAP Kiln Control Mobile app.
All you have to do is open the app, select your kiln, and tap the Settings icon at the bottom.
Scroll down to the Preventative Maintenance section. Here you can use manufacturer spec sheets to enter:
- Relay Life
- Element Life
- Thermocouple Life
Your controller will then track the usage of these components to tell you when it’s time to replace them!
Explore Programmable Digital Kiln Controllers by SDS Industries
Power your at home kiln with the most advanced, easy-to-use kiln controllers on the market!
The TAP II and TAP II Pro Controllers by SDS Industries provide artists with intuitive touchscreen controls, PID-driven precision, and the ability to name, save, and access and unlimited number of firing schedules with an unlimited number of steps. That means that you can easily save, access, and execute the firing schedules for all of your projects – without having to dig through your kiln notebook or look up schedules online.
With integration to the TAP Kiln Control Mobile app, you will be able to monitor your projects in real-time, receive real-time alerts, and enjoy remote kiln control through your smartphone or tablet!
We invite you to explore our selection of programmable kiln controllers, standalones, and conversion kits on our online store. You can also purchase TAP Digital Controllers or TAP Controlled Kilns and Heat Treat Ovens through one of the following distributors:
- Evenheat
- Hot Shot Oven & Kiln
- Paragon Kilns
- Mobile Glassblowing Studios, LLC
- Jen-Ken Kilns
- Kiln Frog
- Sheffield Pottery
- Delphi Glass
[H2] Kiln Maintenance FAQ [H2]
Should I factor maintenance costs into my kiln budget?
Yes! If you’re shopping for kilns, it’s important to be aware that purchase costs aren’t the only cost of owning a kiln. You’ll also need to budget for possible installation expenses, kiln firing costs, and – of course – kiln maintenance.
How much do you need to set aside? That depends on how often you use your kiln, the temperatures you fire to, as well as the specific components your kiln manufacturer uses.
For instance, if you regularly fire cone 10 porcelain, you’ll need to replace your kiln components far more often than if you just use your kiln for fusing glass, heat treating knives, or other processes that require lower firing temperatures.
In terms of kiln maintenance, you will need to budget for regularly replacing the following components:
- Mechanical Relays: $100-$200 every 12-24 months (or approximately every 200,000 cycles). One way to save on kiln maintenance costs is to invest in a solid-state relay, which will be more expensive upfront but will probably outlast your kiln.
- Thermocouples: Around $25-$80 every 30-50 firings for a high-quality replacement for a Type K thermocouple. Your replacement cost may vary based on the thermocouple you use.
- Kiln Elements: Anywhere from $47-$700+ to replace your elements every 1-5 years.
- Kiln Bricks: This isn’t a regular maintenance cost – but you’ll want to set aside money to replace or repair bricks that become worn, crack, or lose insulation.
In addition to tracking component usage automatically through your TAP Controller, we also recommend regularly visually inspecting your kiln to stay on top of any maintenance needs.
How can I avoid kiln relay failure?
When it comes to kiln safety and maintenance, one of the most potentially disastrous risks is if your relay fails in the “on” position. This causes your kiln to heat up indefinitely, potentially causing a fire and putting your project, your kiln, and your property at risk.
Luckily, this outcome is easily avoidable with a little bit of precaution and oversight. Below are tips for avoiding kiln relay failure:
- Regularly Replace Mechanical Relays: If you’re using mechanical relays, it’s important to regularly replace them before they’re at risk of failure. We strongly encourage you to track relay usage and set preventative maintenance alerts with your TAP Kiln Controller.
- Invest in Solid-State Relays: Upgrading to a solid-state relay (SSR) is a great way to protect yourself from the risk of relay failure without proactive maintenance. As long as your SSR is properly ventilated, it should last the lifetime of your kiln or oven.
- Use a Safety Limit Controller: Finally, even if you conduct regular maintenance or have an SSR, it’s good to have another layer of protection! Wiring a safety limit controller like TAP Monitor [DIY Components] to a redundant safety relay protects your kiln and your property even if your primary relay fails.
Where can I learn more about kiln maintenance and safety?
The TAP IN blog is an amazing resource to start learning about kiln maintenance and safety. But how awesome would it be to have a complete, easy-to-understand guide for operating and maintaining your kiln all in one place?
Our friend, Gail at KilnAcademy.com, has created exactly that! The Ultimate Guide to Kilns and Ovens has everything you need to accelerate your learning curve and fire with confidence. This comprehensive guide includes:
- 300+ pages of accurate, up-to-date guidance for kiln installation, setup, maintenance, firing, and more.
- A 2-hour video class that you can follow along with.
- Downloadable checklists for kiln firing and kiln maintenance.
- Options to purchase digital versions, hard copies, or just the video class.
We encourage you to check it out!
