I wanted to warn people about the possibility of a tumble dryer fire. With recent horror stories about Hotpoint and Indesit dryers catching fire, it is worth going in to some details. As an ex-manufacturer service engineer, I was sceptical about the fix Whirlpool have implemented on their machines.
To me it seemed like papering over the cracks rather than solving the root cause of the problem. I believe there is a chance of seeing more tumble dryer fires in future, from theses models. It would however, be unfair to lay all the blame at the feet of Whirlpool. Whirlpool bought out the Hotpoint/ Indesit brand some time ago, and the quality of their merchandise had already been in rapid decline for a while.
A Legacy In Tatters
Perhaps a few decades ago, Hotpoint always had a good reputation for producing quality wares. It was not unusual to find stuff purchased in the 1980s to still be running over fifteen years later if it had been well maintained. In fact, I have come across some customers who have had Hotpoint freezers and cookers for 25 years which are still going strong. Imagine a freezer manufactured today that would last that long?
Indesit on the other hand, were commonly referred to, by engineers in the trade, as Indesh*t. It should be no surprise that now Indesit and Hotpoint models are all but identical, other than the decorative plastic fascia on the front. It is almost as if the Hotpoint brand has been levelled down. Years later they were bought out by Whirpool, who took on their legacy and got stung by this whole saga.
Whirpool were probably rubbing their hands with glee after becoming the worlds largest appliance manufacturer. However, this episode has cost them millions and severely damaged their reputation.
The Good Old Days
The focus on engineering used to be on quality. Engineers used to work on ways to improve the durability of their products. That is how brands used to build their reputations. Stuff breaking down all the time was one way to damage your brands reputation. However, these days due to all the clever marketing, reliability has almost become negligible.
Take a washing machine that breaks down in three years; this is viewed as par for the course now. Of course this is no accident. Whilst there was always commercial pressures to find the cheapest way to do things there always used to be a balance between cost and quality. It seems that this balance has been somewhat skewed in recent years.
As I have discussed previously, the statement “They don’t make ’em like they used to” is taken as matter of fact. It is is repeated so often as to become a mere platitude. It is half a complaint about quality, and half of a harking back to the good old days when stuff was better engineered.
I suppose in one sense, it is a slamming indictment on the way in which our societies focus on the race to bottom has replaced reliability with cheap as possible. In this sense, how can anyone take pride or accomplishment in many of the things we make a commodity?
When we race to the bottom for cheapness, we are left with crap stuff that won’t stand the test of time, and nobody takes pride in making it. The thing is though, its not supposed to stand the test of time anymore. It is designed to fall apart after the warranty obligations have expired, so they can sell you another one. Yes, this actually happens in real life.
Having agreed that stuff isn’t made too well any more, we can take a look at how tumble dryers works.
The fundamental concept of tumble dryer design is airflow. Basically, air is sucked in through the intakes and in to the heater unit by a fan. Warm air is then channeled through an inlet to the drum. The warm air passes through the clothes falling around in the drum, which evaporates the water. Not only does the air hold moisture, it also carries with it loose fibres and dust from off the clothes.
This is commonly referred to as lint and this is what you find deposited on the fine mesh filter in the front. The air is pushed through the outlet and this filter. Then, depending on whether you have a vented or condenser dryer, the air is outlet through the exhaust port. In the latter, the warm air is pushed through a condensing chamber. The warm air hits cold metal and the vapour rapidly condenses. This water, now having been liberated of moisture, is recirculated back through the machine to the heating chamber.
As the filter blocks up with lint, it reduces the airflow. Not only does this reduce the drying efficacy of the unit, it also causes the airflow to be impeded when it goes through the exhaust port or condenser. This then causes depositing of lint inside the machine. Over time this depositing builds up and eventually it can clog up to the point where it starts to restrict the airflow even with a clean lint filter.
It should be clear that blocked lint filter = bad. This is why you should clean it every single time without fail, no matter which manufacturer you bought it from. If you do two cycles without cleaning it, you are starting to leave lint deposits inside your machine.
One of the side effects of this, is that as the normal airflow decreases, it causes the pressure to increase inside the drum, as it is more difficult for the warm air to escape. This causes the damp air to be forced out through the front seal of the drum. It is here, where you start to get deposits building up inside the machine.
Over time as this depositing increases, it starts to be sucked in to to the heater air inlet. As dust passes through the heater it tends to burn up quite quickly if it catches on the element. However, if it passes through it can land on the element housing. As time goes on, this can start to build up inside the heater itself.
When the drying efficiency of the machine is reduced, in condensor dryers damp air is recirculated through the heater. The damp lint contained in this air often passes through the heater without burning up and as it is damp it is more easy for it to cling to the sides. With vented dryers, if there is poor ventilation and exhaust fumes are not expelled, damp air can recirculate inside the machine and cause the same problem.
This situation then becomes compounded further if ever the lint filter starts to get blocked. From here, the dust is pushed through the heater housing and cannot enter the drum as easily due to the higher pressure already present. This causes an eddy current behind the drum and the dust settles on the rear seal. Over time this builds up until it reaches the height of the heater inlet.
Once it starts to lean over the heater, it is only a matter of time until a large chunk hangs directly above the heating element. Then you have an ignition source which can spread inside the heater housing and its game over. This process is exacerbated by having dust already built up inside the machine as it is more likely to get caught in the recirculating air current..
Issues With Tumble Dryer Design
The trouble with certain dryers is that the air is not ducted. That is to say, that stray lint can reach any point of the machine easily. Whilst most of the time this lint is harmlessly burnt off if it gets in to the heater, in some instances it causes problems. I can’t help but think if the airflow was ducted in the affected whirlpool dryers, then there wouldn’t have been an issue.
I think as a consequence of engineers applying the “How can we do this cheaper methodology”, it has resulted in this situation. As subsequent engineers remove bits of ducting and other things that help with airflow, it has compromised the units actual safety.
In all fairness to the engineers, they have to make assumptions about airflow. I don’t think their model takes in to account people who don’t clean out the lint filter properly. Since the manufacturers recommend this is done, their model clearly doesn’t take this in to account. If it did, they would have realised that an eddy current could occur behind the drum and cause dust to be deposited on the inner seal. Naturally this is contingent on impeded airflow which I don’t think they adequately modelled for in their testing.
I’ve lost count of people who have complained that their dryer doesn’t dry clothes well anymore. It is usually down to blocked airflow rather than the actual machine, however, the thought of it going on fire is a cause for concern.
The Modification For Preventing Tumble Dryer Fires
The ‘fix’ in essence, is simply to put a rivet in the drum. The back panel is also changed so there is a better seal between the drum and panel. This seal is supposed to prevent any dust getting in behind the drum from inside the machine. However, the bulk of the dust that ends up there actually gets sucked in through the heater intake. This is clearly evidenced in the photos. As a side effect, the friction is increased between the front drum mount and this causes the machine to make more noise.
Moreover, the rivet is supposed to run on the inside of the rear seal and prevent the dust from having chance to build up. Only time will tell if this is effective, however, it is not immediately clear how dislodging chunks of dust near the heater is going to prevent fires. In this sense, there are still questions hanging over these fixes. The new rear seal is negligible and causes noise. The rivet knocks off chunks of dust near the heater. It still does not address the issues regarding poor maintenance of the lint filter, and if the operator neglects cleaning the lint filter, the machine will still back up with dust. This means the heater can still choke up with dust and pose a fire hazard.
Root Cause of Tumble Dryer Fires
Now I might be unfair here, but there is one contributory factor that we have not yet made explicit. Most tumble dryer fires are caused by poor maintenance. There I said it. There are a few caveats but in essence if you look after your dryer it should give years of trouble free service and won’t catch fire. Even if you have the best tumble dryer in the world if you don’t clean it, eventually it will catch fire.
I dare say the infamous Sheppards Bush tumble dryer fire in the tower block, was caused by poor maintenance. Without knowing the particulars I am merely speculating. However, this speculation is not merely idle. I like to think of it using the coffee cup analogy. Basically, the operator is responsible for not burning themselves with their hot coffee. Compensation culture tells us that we should blame others for own stupidity or bad luck. Now we have a situation where coffee cups have a “Caution: contents may be hot” warning sign printed on them.
I have seen dryers back up to the point of a fire risk in as little as under a year. They claimed they were cleaning the lint filter but nobody tends to admits that they are at fault. It is quite easy to tell as signs like this are a dead give away.
In their defence though, people just don’t tend to have time. The worst offenders are young families who are busy.
Since we are all rushed off our feet, things can easily get left by the wayside like cleaning the lint filter, cleaning the fridge and so forth. Its quite easy to see how chucking school uniforms in the tumble dryer while getting tea ready and stopping kids from playing up, is a distraction. In all fairness, pensioners with a bit more time on their hands tend to be better at cleaning lint filters regularly. I guess they were also more aware of electrical goods going on fire from poor maintenance than we are too.
The worst places though were holiday lets and shared laundry facilities. People didn’t have to care too much at these places because they expect someone else to do this job. I often found machines that were not far off from being a severe fire risk at these places.
It is six of one and half a dozen of the other. Cuts made to save money have led to safety issues, coupled with poor maintenance on the part of customers and this incendiary situation has arisen. I don’t think it is fair to blame Whirpoool entirely for this as such, however, their poor response, lacklustre effort and lamentable attitude to customers has made it far worse.
At the end of the day, things need to be fool proof. If someone doesn’t clean their lint filter they are asking for trouble. However, that does mean that there should be some kind of safety mechanism to prevent a fire. It is the companies responsibility ultimately. Yet some people have had these machines for 10 years, and have never had a lint build up as they were properly maintained.
The truth is most people won’t have a fire if they are sensible and maintain them properly. However, the machines safety was inadequate here as a result of cost cutting measures. The fact is the countermeasures were non existent and Whirpool did themselves no favours by not admitting to the problem and treating customers with utter contempt.
Whilst this has been all about problems we need to look at the proactive solutions we can take. Here are the top tips for correctly maintenance, so as to prevent the risk of a tumble dryer fire.
You must clean the lint filter every single time without fail. This prevents the build up of lint inside the machine, it is essential this is done. In fact, you can even clean it out halfway through the cycle if you wish!
Don’t put clothes straight out of the washing machine in to the dryer. Believe it or not, the damp lint clings inside the dryer more easily. The correct usage practice is to air dry clothes off a little, and then use the tumble dryer to finish them off. This also saves energy as you don’t have to have the dryer on for two hours.
Check inside the lint filter housing. If you get a build up of dust, then hoover it out with an attachment. Keep this area clean, signs of a build up here are signs that your machine is filling up with lint. This is a no no.
Inspect air inlets. On vented dryers the air inlet is often at the top on the rear of the unit. On condenser dryers it is often situated on the front. Any dust here is a sign that there is a build up starting inside.
On condenser dryers check for signs of build up in the condenser unit. Manufacturers recommend this is cleaned monthly, however, from light use this is excessive. It should be self evident when it needs cleaning. If you remove the condenser and you get a large surge of water, this means the sump is probably blocked or the pump has failed.
With vented dryers you need to check the. exhaust port and vent hose are free from debris. Any debris here will impede the airflow. The vent hose must be positioned so it is not kinked as this will cause impedance. The exhaust air should not have chance to recirculate back to the inlets or else the machine will clog up in no time.
Do not open the door to interrupt the cycle. When you do this the fan cuts out and there is a massive temperature surge in the heater chamber. Not only will this wear out the thermal cut out switch prematurely, if there is any dust build up it could ignite inside the machine.
Do not operate tumble dryers in cupboards with the door closed, it must be ventilated so leave the door open. When operating them it is wise to have a window open to allow fresh air in if possible.
Airflow is the biggest factor in ensuring you don’t run in to problems.
If in doubt get it checked out. It is worth having your dryer serviced annually if you use it constantly. Otherwise every few years will suffice. Mr Circuit will service your dryer and repair any problems for the best price in town. Special offer: *****Belt and bearing change now only £40 inc. parts, labour & free service include. (Whirpool all inclusive price under free parts guarantee = £70!)*****