Common Oven & Hob Problems
Last Updated: 11 Feb 2016
A faulty oven or hob can lead to an expensive repair bill or worse still to the cost of a new replacement. However, in many cases the problem with your oven or hob is easily fixed if you know how. First we're going to take a look at how an electric oven works and then go through the common problems that can arise, and hopefully give you solutions on how to fix any faults.
How An Electric Oven Works
To help diagnose problems and replace faulty components on your electric fan assisted oven it is first necessary to understand how it works. In the video above we used a built in fan assisted Indesit oven to explain each of the main important components and how they work together.
The oven is a single cavity oven which means as well as being a fan assisted oven it also includes the grill as well. Some ovens are twin cavity which simply means that they have a separate oven and grill.
Let’s take a look at all the main components of the oven and how together.
Oven Element, Thermostat, and Fan
First we’ll look at the oven Element, thermostat, and fan.
The main function of an oven is to heat up and cook our food. The heating part of the process is done by an oven element which is normally situated at the rear of the oven. Most ovens nowadays are what’s known as fan assisted. This means that at the same time the oven element is heating up there is also a fan which distributes the hot air around the cavity to ensure even cooking throughout the oven.
Temperature is regulated by the thermostat. To us this is simply a knob which we turn to our desired temperature. But behind the knob is the thermostat switch with a capillary (wire) running from the switch and down in to the cavity of the oven. The capillary is actually a tube with gas inside. As the gas heats up the pressure build up causes small bellows in the thermostat switch to move until they reach the predetermined temperature set by the user. The thermostat will turn the oven element on and off during the cooking cycle as the temperature gets to hot or too cool.
The fan should always be on when the thermostat knob is set at anything other than off. There are normally two fans in an oven; the fan that distributes the hot air to aid cooking, and a cooling fan.
Cooling Fan and Thermal Switch
Next we’ll look at the Cooling Fan and Cooling Fan TOC.
The cooling fan is designed to keep the area between the cavity and the outer casing cool. It is a cylindrical fan and is operated by a Thermal Switch automatically depending on the temperature. As the temperature rises it cause a bi metallic strip inside the TOC to turn the cooling fan on. As the temperature cools the bi metallic strip breaks the contact which turns the cooling fan off. When you finish cooking and turn the oven thermostat off the cooling fan motor should (depending on temperature) still be running and will run for 10 minutes or so until the oven has cooled down sufficiently.
Grill Element and Energy Regulator
As with the oven element the grill element is responsible for the heat needed to grill our food. The grill element heat settings are controlled via an energy regulator that sits behind a knob on the oven console. The energy regulator regulates the heat output by the amount of power sent to the grill element which is determined by the user.
On this oven the function switch is combined with the thermostat. This switch simply enables the user to select which part of the oven they want to use. So if I want to use the grill I need to select the grill on the function switch before it will work.
Door Glass, Door Seal, Door Hinges
Although the door area may not seem as important as the other components we’ve discussed any damage or wear to them will likely lead to poor cooking performance. There will normally be an inner and outer door glass. This is to ensure that the temperature of the outer door doesn’t get too hot. Obviously if there are any breaks or cracks to either door glass then they should be replaced without delay.
How to replace the door glass on an oven:
The door seal is normally fixed with clips in each corner and should be in good order and free from sagging. If the seal is worn or is sagging then heat will be allowed to escape and cooking performance will be affected. It will also have an effect on the amount of energy your oven is using to maintain the temperature set. Changing an oven door seal is a straightforward job.
How to replace the door seal on an oven:
Over time the spring within the door hinge can become sprained which will result in the door not closing properly. The only solution to this fault is to replace the oven door hinges. Fortunately replacement is straightforward and we have a video showing you exactly how to do it.
How to replace the door hinges on an oven:
Why Won't My Oven Heat Up?
As the old adage goes; if you can’t stand the heat, stay out of the kitchen. However, if your kitchen’s not actually generating any heat – specifically from the oven – then you’re in even more trouble.
Checking The Elements
The heating elements which heat up the oven can burn out and are the most likely cause of an oven not heating up; if they do, they won’t work or heat up at all. These are relatively easy components of the oven to replace – most are simply held in place with a couple of screws and have 2/3 wires going to it, and can be fitted easily without the need for specific technical knowledge or experience.
The heating element can usually be found at the back of any fan oven, behind the back plate. To check it, you will need to turn off the power before opening up the back of your oven. Removing the heating element is a case of very carefully detaching the wires before completely retrieving the heating element.
How to replace an oven element:
Although the thermostat can cause the oven not to heat up it is more likely to be a faulty element. The thermostat is a switch that regulates the temperature, if the thermostat has a malfunction it may not be able to turn the heat on.
How to replace an oven thermostat:
Cooking On Gas
Of course, not everyone has an electric oven – some people use good, ol’ fashioned gas. If you do, check your igniter, which is situated next to the burner.
It’s possible you could have a faulty gas safety valve, in which case you can check that too.
The burner contains a lot of small halls for the flame around the burner, and some them get clogged thereby preventing the burner from lighting properly. A good quick fix for this is to clean the holes out with a needle or some wire.
If you can smell gas, leave your home immediately and call the National Gas Emergency Number, 0800 111 999. Oh, and always remember any repairs to gas appliances MUST be carried out by a 'Gas Safe' registered engineer.
Too Many Switches
Lots of ovens – particularly the more complicated, contemporary ones – are adorned with switches, knobs and an eye-popping panoply of buttons.
If things get a bit complicated and you’re getting flustered firing things, consult the manual no matter how confident you are – or you may end up creating more problems.
In most cases the oven needs to be in ‘manual mode’ otherwise it won’t work at all!
Out Of Power
One of the basics, but if there’s no electrical current surging to the oven, you’re going to be waiting quite some time until that cottage pie’s ready.
Check the circuit breaker and make sure it’s flipped to the ‘On’ position, as a sudden electric surge can cause it to overload and trip out. If you cannot make it click or lock back into the ‘On’ position, chances are there’s either a fault with the oven or the circuit breaker switch is faulty and will need to be replaced.
As a sanity check, make sure the oven’s plugged in, or hasn’t been pulled out of the socket slightly.
Why is My Oven Overheating & Cutting out?
An overheating oven is a common problem, and can result in you burning or overcooking your food (a serious issue for any food lover!). But don’t panic – most of the common causes of the problem are easy to fix.
Thermal Overload Switch
There is a real safety consideration if your oven is overheating and it should be repaired as soon as possible. Whilst there will be a thermal overload switch fitted inside your oven which will trip and turn off the power to the heating system, it shouldn't be relied upon and is a warning sign that you have a problem. Your oven will likely work again once it has cooled down but you are advised not to use it until the root cause of the problem has been fixed.
Faulty Oven Thermostat
The most likely cause of an overheating oven is a faulty oven thermostat, which will result in an inaccurate temperature setting. Thermostat replacement is a straightforward DIY repair task.
See our 'oven thermostat guide' for more details on advice and fitting.
Faulty Oven Cooling Fan Motor
If the fan isn’t working at the correct speed, the oven may overheat – and this is likely to be due to a faulty oven cooling fan motor.
How to replace a fautly cooling fan motor:
Blocked Oven Vents
Blocked oven vents are another possible cause of an overheating oven. To fix the issue, make sure that any vents aren’t blocked.
Faulty Control Module
In some cases, a faulty control module may be the cause of the problem. To fix the issue, you’ll need to replace the control module.
Why is My Oven Is Smoking?
If you’re ever confronted with a smoking oven, use an extractor fan when dealing with it.
It might just need some elbow grease!
It may be the case that your oven gives off a lot of smoke when it’s empty, in which case it’s probable that there’s a build-up of burned food and/or grease. In these situations, it’s best to let the oven cool down. Once it has, clean it out and rinse it thoroughly. We recommend a Professional Oven Cleaner as it always gets fantastic reviews. Make sure it’s completely dry before you use it again.
However, if your oven’s already been cleaned and gives off anything more than a small amount of smoke, turn off the oven straight away and wait for the oven to cool down. It’s probable that the residue of a cleaning product has built up inside the oven. Once it’s cooled down, rinse the oven out thoroughly with water, and make sure it has dried out completely before you use it again.
How to clean your oven:
Is your oven new?
Brand new ovens also give off small amounts of smoke the first time they’re used.
Good general maintenance advice is to clean your oven after every time you cook in it, particularly if it’s food with a lot of fat that might spit inside the oven.
Self-cleaning ovens may cause small pieces of caked-on food to catch fire – but do not open the oven door or try to put the fire out if your oven is self-cleaning.
It’s also possible that a short in an electric oven will cause the components to smoke. In a situation like this, you’ll need to call in the assistance of an expert repairer.
If you've just replaced the oven element in your oven then it is normal for it to smoke the first time it's used.
Why Won't My Oven Turn On?
The general solution to this problem will change depending on what kind of oven you have. Gas ovens are more dangerous than electric ovens to fix yourself.
Gas oven won't turn on
If your gas oven doesn’t turn on, you should seek the opinion of a registered ‘Gas Safe’ professional in the first instance. Problems with gas ovens can be dangerous for amateurs to fix, and improper fixes can lead to dangerous problems building up over time.
Electric oven won't turn on
Before you do anything first of all check that your oven is set to manual. If it's not then your oven will appear dead. Normally there is a symbol or icon that looks like a 'high five' hand and pressing this will re-set your oven to manual.
Next you need to ensure that electric is getting to the oven. If it is a plug in type then check that the socket is working by plugging in to it something that you no is working. If it's 'hard wired' in then you will need to check that power is reaching the switch and that the switch is functioning correctly; you may need to employ the services of an electrician to carry this check out.
If electric is definitely reaching the oven then you should check that the terminal block where the wire connects to the oven hasn't burnt out.
If all the above prove to be ok and it appears still that the oven is 'dead' then it could be an internal component at fault and is probably best to employ the services of a repair engineer.
Why Does My Hob Keep Sparking?
Gas hobs can be very dangerous, and small mistakes can cause death or severe poisoning. If you are having issues with your gas hob or oven you should always make sure that a gas safe engineer is called.
Problems are most likely to have originated with electric switches on the gas valves, individual sparkers, the sparker module, or excess moisture after using too much water to clean the hob.
You should not investigate the problem yourself. Call in a professional to sort out the problem quickly, cleanly and safely.
Why Does My Hob Ignition Keep Clicking?
Your hob ignition clicking shouldn't be anything to worry about, as it means that your ignition is working too much if anything. That means that any gas around the hob will be ignited and burned off before it can build up.
There are many potential reasons your hob ignition is clicking, but the most common is that some food or water is causing an obstruction.
Clean the igniter, but be sure to leave the hob dry once done. Too much water will mean that the problem persists, and might have been the cause of the problem in the first place.
If this doesn't fix the problem, check that the microswitch on the hob isn't stuck down. Remove the knob covering it to locate the microswitch. If it is stuck down, and cannot be unstuck very easily, you will need a replacement spark module.
If it's not stuck down, the switch may have shorted. If this is the case, you will need a replacement spark module.
Hob Control Unit
Automatic ignition cookers, where the ignition kicks in automatically when you start the gas flowing, have one more option. It might still be the case that debris, water, or a faulty spark module are your problem, but you may also need a new control unit in some cases.
This is a much less common problem, though, so be sure to check thoroughly for the other potential issues first!
By Lee Gilbert