Imagine a fine wire spiral,. encase it in magnesium oxide powder, then encase it in a metal sleeve. This is how a fan oven element is constructed, but why should it fail? And, when they do, how do you replace them?
Consider that the element is essentially a metal construct, so as it heats it will expand. The motor driven fan central to the element is blowing the heat off the element to disperse is around the oven box, however, this brings the first problem; the inner edge of the element is running at a lower temperature than the outer edge. Next, we have the thermostat causing the element to cycle when it reaches temperature. This is not a sophisticated process; the element is either on or off. As soon as the power cuts off, the element starts to cool, and consequently, contract. This can cause the element to expand and contract by up to 10mm!
|A typical fan element, in this case faulty|
The insulation of the oven is critical to the cycling process. A cheap and cheerful single box oven is likely to be poorly insulated and as a consequence will lose heat quickly. This means that the element will be forced to cycle more quickly.
If we tie this all together, we have a differential temperature gradient on the element sleeve, combined with repeated expansion and contraction and exacerbated by poorly insulated appliances. Thefilament (the "spiral") begins to move in its powder casing and will eventually touch the outer metal sleeve, with the inevitable result.
Other things that can happen include the fan motor becoming caked in grease and running slow as a consequence - this will cause the element to overheat and blow. The thermostat can also fail to cycle; again the element will eventually overheat and fail.
We may conclude that by the very nature of the environment in which a fan oven element lives it will eventually fail; it is fair to say that it is only a question of when.
We are often asked how long an element should last, or is expected to last and I'm afraid that the honest answer is that there is no set expected lifespan. This is simply due to the factors involved as pointed out, that can affect the life and so the answer is, anything from two minutes to twenty years, who knows?
Replacement is usually relatively straightforward.
In this short video we quickly explain how to test a fan oven element to see if it is indeed faulty or not and, our apologies for a little of it wandering out of shot.
It is absolutely vital to do this and DO NOT trust cooker wall switches as they can very often be faulty, especially if they are older.
Electricity kills, do not become a statistic!
This is desperately important!
It is a sad fact that not all elements are equal, like most spare parts that are common there are good copies and there are bad ones. Be very careful what you buy as common issues are:
All the elements that we supply through UK Whitegoods are direct replacements that we would fit ourselves to our own cookers, we don't supply inferior quality elements. Where there is no spar?e of reasonable quality available we will only supply the genuine replacement part.
Yes this does lose us business and, quite honestly we'd rather lose the business than supply something that we are not comfortable selling or that we wouldn't fit to our own appliances. We like to offer the best quality we can at the most affordable prices possible.
You will find that most good appliance engineers take the same stance as we like our customers and, importantly, we like to keep them.
On most ovens and cookers you can remove the rear panel in the inside of the actual oven and access the element.
Usually you can see if this is possible as there will be a retaining screw or nut (at least one) to hold the panel in place, after that you will normally have to lift it or slide it to one side depending on the make, to remove it.? Usually the rear panel of the oven is simply fixed with a couple of knurled screws that you can simply undo by hand.
Once removed you should see the fan element and, inside that, the blades of the actual fan motor itself. Normally you will see the element split or blown something like the example shown in the photographs.
Ordinarily the element itself is fixed to the rear wall of the inner oven cavity by either a single central bolt, two bolts on either side of the fixing bracket or on occasion one or two bolts that have to be undone from the rear, which means taking the oven out from the housing to replace
Whilst you're in there there's a few things to check:
On the whole though most fan elements are reasonably straightforward enough to replace with only the odd one being beyond the capability of a reasonable person with some DIY skills. Most of it is fairly straightforward and simple common sense with the most awkward part of replacing a fan element being working how to get into that particular model of oven or cooker.
A close up of a blown element and you can see the outer casing is clearly split
Make sure that the cooker has not been running or has power on it before you start work on replacing the fan element, one can cause burns and the other can cause burns and far more serious injuries.
Second word of warning, once you have the screws out gently wiggle the element out. Now, be very careful as if the wires fall off then you're going to have to strip the oven down as above.
Third pearl of wisdom. Be warned that most often these wires are short, very short and you will not have a lot of room to work in, welcome to our world!?With all the above information you should be able to replace the element but if this has put you off the idea, or you don't think that you're up to the task then please feel free to use the site to find an engineer or ask in the forums for more advice.