The answer is often, yes! Many times your dryer vent becomes so restricted that it causes a failure within the appliance. So, yes, it is often due to your vent; and, yes, it is often your appliance. The lack of heat is a direct sign of an appliance problem (typically the heating element), but oftentimes is indirectly due to restricted ductwork causing the appliance failure in the first place. I’ve heard many customers recount that the warranty company warned that they would not cover the repair again unless the homeowner got the dryer vent professionally cleaned—otherwise the appliance can just keep failing requiring repair after repair. That is dangerous, and could be a prime situation for a fire to start.

Occasionally, water can accumulate within your dryer vent system so that there is wet, sopping lint. Normally, the moist air from the dryer dampens the dryer vent ductwork, the moisture in the exhaust is largely brought to the exterior, and the dampness remaining in the duct evaporates away. When there is a significant blockage or restriction such that the dryer is unable to bring the moisture outside, the water accumulates within the duct and creates problems. First, it can be very difficult to clean the dryer vent (higher cost) and can also require an additional cleaning a week or two later (extra cost). Second, large amounts of condensed water can leak out of the duct and damage your house. Third, this same water can corrode the galvanized metal ductwork, especially if it doesn't have a way to leak out of the duct. This can require anything from a more isolated repair to a complete dryer vent replacement. This can all be avoided by simply staying up on regular dryer vent cleanings. All these problems become quite costly and can be mitigated by proper maintenance.

There are several factors that contribute to lint accumulation (the topic for another post), and these factors vary significantly from house to house. However, no matter your dryer vent's configuration, the frequency for cleaning is based upon how much buildup occurs in your dryer vent. So how much accumulation should be found between cleanings? Not much more than a dusting. For straight sections of duct we look for no more than a dusting and for your transition duct, around your elbows (turns) and toward your termination cover there will be "balling." Since these latter areas are more restrictive they  have increased accumulation and start to clump up (balling). Those balls of lint should be no more than a quarter in size (and hopefully not that large).

In order to target this level of buildup annual cleanings are preferred for most people. If your vent system is DIY-friendly (only exhausts a few inches through the side of your house and does not require an extension ladder to access), then by all means clean your vent system more regularly. However, for professional cleanings it usually turns out that an annual cleaning does pretty well in targeting the desired level of accumulation. If you go beyond this level you begin to flirt with the fire-hazard aspect of your vent system. In order to incentivize this proper maintenance we give an annual cleaning discount and offer, for a further discount, to schedule your next appointment a year in advance. 

There are a several choices when it comes to termination covers. Plastic or metal; louvered or single-dampere; hooded or flush. Louvered models can have two, three, or four louvers. If metal, they can be paintable, galvanized, or pre-finished. Plastic models can consist of the standard cover or have multiple pieces which comprise act as flashing. Sometimes a termination cover will be installed over the siding, flashed around the siding, or with part of it under the siding. Plastic models can also dramatically vary in quality, leading lower quality models to disintegrate or break easily. There is even a model that has two single-dampers. one on top of the other, to deter bird entry.

We prefer to install metal covers because they tend to last far longer than their plastic counterparts. By far and away, the most popular model we install is this:

Why do we like it so much? It is the most attractive and efficient cover on the market (that we are aware of, at least--and we are aware of most of them!). Also, it is more easily cleanable than other metal models, ensuring the damper remains functional. Perhaps most importantly, it has a couple layers of bird resistance built into it so as to thwart off avian entry. (However, there is also a matching bird guard to definitely ensure that they stay out!)

Something that can need to be replaced is the dryer's transition duct. The transition duct connects the duct from the dryer to the main ductwork that begins in the wall/ceiling/floor. There are a few things to bear in mind regarding transition ducts. Firstly, they should be of the appropriate material. This means that it should be a heavy metal material. Slinky foil ducts should not be used--ever--in the dryer vent system. Typically, the choice material for transition ducts is semi-rigid duct. This allows for heavy metal material while maintaining flexibility while connecting the dryer. Secondly, the transition duct should be of the appropriate length. Code requires that the transition duct not exceed eight feet. Unfortunately, eight foot sections of semi-rigid duct do not actually equal eight feet--they are often closer to six feet when extended. This means that in certain longer-length situations the main duct needs to be extended in order to bridge the difference. Thirdly, the transition duct should not extend out of the laundry room area. Non-rigid material certainly cannot penetrate past the wall/ceiling/floor of the laundry room such that it is concealed. Lastly, the transition duct should be listed as in accordance with UL2158A.

Over the last few decades, architects have begun to design laundry spaces with convenience in mind. As a consequence the laundry room has become more and more centrally located in the home. This has largely created the need for professional dryer vent cleaning, since most homeowners are not aware of the proper procedures for cleaning a dryer vent nor do they have adequate equipment to clean these longer vents. Instead of a vent running a few feet to the exterior, the modern vents may be ten times that--and behind finished spaces.

A dryer vent exhausts hot, moist, linty air (and resultant gasses of combustion if it is a natural gas dryer) from the dryer to the outside of the house. Although I've seen dryers vent into crawl spaces, attics, joist cavities, or just straight into their own laundry room, none of these scenarios are permissible. The dryer must vent to the exterior.

To create the dryer vent, a route must be established from the dryer to either the roof or exterior wall that is within the overall length guidelines and also is able to be efficiently routed. This dryer vent system is comprised of several items:

• Transition duct -- should be rigid metal or semi-rigid metal. This is the duct that connect from the dryer to the main duct.
• Main duct -- should only be heavy gauge rigid duct. This is the duct that connects from the laundry room to the exterior.
• Insulation -- wrapped fiberglass. This is recommended for ductwork in unconditioned spaces.
• Termination hood -- ideally metal without a pest guard. This is what the duct connects to and interacts with the outside world. It's what you see of the dryer vent system from the exterior and it is the actual point where the exhaust leaves the dryer vent.

As the exhaust travels through the dryer vent system, the moisture condenses on the inner wall of the duct. The condensed moisture then pulls the lint out of the exhaust and causes it to accumulate. As this happens, the airway slowly chokes down in size (1/2" of inner wall accumulation restricts the duct by almost 50%). Also, as the velocity of the exhaust stream dissipates over the distance of the ductwork, then further accumulation occurs.

I hope these basic help you understand your house's dryer vent better.

Here's a quick post regarding the three most common items needing replacement in a dryer vent system.

1) Transition Duct -- this is the duct that joins your dryer duct to the main duct. This should be made of heavy metal, but often it is not. There is a sticker on the back of most dryers that clearly specifies this.

2) Termination Hood -- this is where the exhaust system meets the exterior. The termination hood can be through the wall or roof (either is ok!) and there needs to be a damper integrated into it (whether a single damper or louvers). Plastic termination hoods are not recommended because most crack and break apart after a few years.

3) Main Duct -- sometimes a builder has installed an improper dryer vent and it needs to be replaced. "Slinky foil", vinyl, and semi-rigid are all insufficient materials to act as the main duct. In this case, the main duct will need to be replaced with heavy-gauge rigid material.

Each of these can vary much in replacement difficulty and complexity. A handy homeowner might tackle easier scenarios, but for more challenging situations a professional installation may be required.

Today, as I serviced one customer's house, the homeowner and I were discussing the importance of dryer vent cleaning. In our conversation I think she summarized it well: the main impetus for dryer vent cleaning is to mitigate the fire hazard, and shorter drying times and less energy usage are merely extra benefits.

You want to be cleaning the vent before excessive accumulation occurs, otherwise you begin flirting with the fire hazard. This means that if you follow the industry recommendations for intervals between cleaning (typically 1 year) you probably won't experience a dramatic change in drying times or energy usage (unless birds get in your vent!), but you will be following 'best practice' in order to mitigate the fire hazard.

It is always satisfying when I leave a home knowing that the owner(s) will experience substantially shorter drying times. It is impressive removing large amounts of lint or multiple feet of a bird nest because I know that there will be a drastic difference in airflow before and after cleanings. However, truth be told, I am much more satisfied leaving a home that has been maintained with regular cleanings and has removed marginal accumulation because I know that the family, house, and appliance are being safeguarded.

There is a reason that cleanings are recommended annually, and not every 5 or 10 years.