Fault Finding For Cooker Hoods

Cooker hoods are usually simple enough appliances to diagnose faults on and to repair or, they are at least to professional appliance repairers like ourselves.

If however you have no experience with them and take a peek inside you will very often see little more than a few enclosed housings and, quite probably, have no idea what is in behind the plastic cowls and covers. The good news here is that, for the vast majority of cooker hoods on the market the answer to the question of what lies beneath the covers is, not a lot really.

  Cooker Hood Component Parts

In most cooker hoods, whether they are built in or integrated, island type, chimney and the common garden variety basic cooker hood there’s a handful of components in there, they are:

• Motor: to draw the cooking air and odours into the hood and expel it to the outside or back into the kitchen
• Lamp Holders: which hold the light bulbs in the cooker hood
• Bulbs: we all know what that is although there are various flavours of bulbs used on cooker hoods
• Control switch or PCB: this controls the speed of the motor and the lights usually

And, pretty much, that’s it. There’s only really four things that can go wrong in almost all cooker hoods.

Some fancy upmarket cooker hoods have an additional power board for the motor or, a remote control board and a switch only type electronic touch control at the front control panel but they’re best left to people that know about them and, if you bought one as fancy as that then you should be prepared to pay for any repairs that may be required as it won’t have been cheap.

You can also get remote motor hoods and, again, our advice would be not to mess with it, get someone that knows about this type of cooker hood to repair it for you as it’s much harder.

  Poor Cooker Hood Airflow Or Extraction

This we only usually hear of when a cooker hood is newly installed, it’s rare to get this on hoods that have been in a while as, if the motor fails then ti will fail  completely. Or, put it this way, we’ve never seen one fail partially in about 100 years of collective experience so, it’s extremely unlikely.

If you get poor airflow or extraction from your cooker hood it is far more likely to ba an issue with the vent to the outside or a simple case of the filters being blocked. 

  Cooker Hood Lights Failed

This is probably the single most common fault with any cooker hood.

There are also several reasons for it, some of which some people really don’t like being told about when they find out that they can’t have the lights on the cooker hood on all the time, which you can’t or at least shouldn’t.

Most cooker hoods are, let’s face it, cheap and nasty. The ones you get thrown in with most kitchens are the cheapest that the retailer could get and most people either don’t think or, don’t care about the cooker hood, it’s just an afterthought. So you get loads of them that don’t perform very well and have, let’s say, “quality issues”.

But they are cheap.

  Running the Cooker Hood For Extended Periods

If you run the lights all the time, especially simply for the effect, then the chances are that you will burn the plastic holders or clips that hold the lamp glass in place, it’ll fall down and smash on your hob or cooker and, that’s not good. But, if the bulbs weren’t switched on for extended periods beyond what the hood was designed for then it’s not a problem.

Then there’s the issue with the electronic modules that often switch the lamps on and off, these can also get hot and effectively fried just because the lights are left on for ages.

And of course, we have the lamp holders and, the same applies, if the lamps are left on for extended periods these will melt (as they’re usually made of plastic largely) and fall apart.

Most cooker hood bulbs and components are designed for light use, especially the low cost cooker hoods and not designed to be left on for extended periods of time.

If you get bulbs popping on your cooker hood all the time, this is probably the number one cause of the fault.

  Other Causes For Lamp Failure On A Cooker Hood

Other than the above the other things to check are the mains voltage supply as, if that’s not quite right it can give you issues with bulbs blowing prematurely as well as issues with the control module if your cooker hood has an electronic control in it.

Also check the lampholders as well as fi they have poor contact with the actual bulb it can arc can cause the bulb to pop.

The last resort is the control switch or control module for the cooker hood itself. Usually the lamps are controlled on a separate circuit within this so that they can be switch on and off without the motor having to be on, if that particular circuit fails for some reason then the lights will not work.

Beyond that, there’s really not much it can be.

  Finding Other Faults On A Cooker Hood

As we’ve said, cooker hoods tend to be rather simple appliances and, as such there’s not a lot in them. To demonstrate this we’ll show you a wiring diagram for a typical chimney cooker hood.

This shows you how simple the wiring is in a typical cooker hood. As it is so simple it is very easy to trace and find faults but this will often require that you trace the wiring if something isn’t working. Of course, remembering that working on a live appliance is not acceptable for safety reasons. On this cooker hood you have the additional complexity of a transformer for the low voltage lighting as well as a control board with a seperate user input board and, even with that, it’s still not that complex really. For the vast bulk of cooker hoods, the wiring will not be far away from this and, as you can see, virtually every component is routed through the main control switch or electronic module. Because of this it makes the control module or switches the spot where failure is most likely to occur and, does.

By far and away the next most common fault is of course the electronic control module or switch. Contacts or relays blow, tracks lift and so on with regularity and this is the weak spot on most cooker hoods.

Motors rarely fail. Cooker hood motors do fail, but nowhere near as common as the other faults above so look to the main control board or switches before you go to the motor looking for a fault as they are rarely under any stress.

  Cooker Hood Spare Parts

As a spare parts company we can supply almost all cooker hood spare parts that are available but, in order to ensure that you get the correct spare part for your cooker hood it is absolutely essential that you have the model number of your cooker hood at the very least. For some makes you may also need to have production numbers or serial numbers as well.

If you can’t find it or aren’t sure please ask, it’s better to do that than get the wrong parts.

Cooker hoods are not all the same and, like most appliances, they do not (or rarely) use standardised parts.

Do not order merely off a photograph as a lot of cooker hood spares all look the same, especially the ones that you are liable to need like motors, control boards, lamp holders and filters.

The only standard parts are universal cooker hood filters, both grease and carbon filters and bulbs. Beyond that, they are by model and serial numbers only.