Tumble dryers, particularly condenser and heat pump dryers can be complicated to strip down and get back together!
Metallic scraping noise
Metallic scraping noises should not be ignored. This sound usually means the metal drum is scraping on something as it revolves. If ignored, serious wear can occur. As you can imagine, something metal constantly catching on something else – even something else metal – will inevitably result in wear of one or both of the parts involved. I’ve seen many simple faults ignored until only a very expensive repair will fix it.
Other metallic scraping noises could be caused by the plastic bearings the drum rests and rotates on wearing down so much that the lip of the drum at the front can scrape on metal.
Make sure the dryer is level. If not level the cabinet can slightly twist causing drums to catch on nearby parts. Hotpoint and Indesit tumble dryers used to be terrible for scraping noises, and they brought out modifications to try and address the problem. It’s hopefully solved by now, but cheap dryers, or even expensive ones not well made, can have flimsy casings which twist easily and have too little clearance between the revolving drum and the back panel.
These can be caused by tension pulleys which usually tension the drive belt and revolve all the time the drum is turning. They are small wheel-like plastic parts that are held against the drive belt with strong springs, and run on a small metal shaft. They commonly dry out or wear. The proper cure for this is to replace the pulleys and the shaft they run on, or at least strip them, clean them and grease them with high melting point grease if they aren’t too worn. Unfortunately though these tension (or jockey) pulleys are not usually accessible without stripping the dryer down though some dryers allow you to remove a side panel if you can work out how to take it off.
On some tumble dryers are dry or worn bearing can cause squeaking noise. This is particularly common on some Indesit or Hotpoint tumble dryers. Check out the comments below where 2 people have contributed their experience on how they dealt with their squeaking tumble dryers.
Deep rumbling noises can also be caused by the same belt tension pulleys from the last section. Depending on their design they can develop squeaks or a rumble. So can worn drum bearings, which are usually just shiny plastic parts the drum rests on at the front and a single brass bearing at the rear centre of the drum.
The motor can of course become noisy, though it is pretty rare because they revolve so slowly that they don’t tend to wear much. If the belt is removed and any tension pulley brackets moved out of the way a motor can be run on its own to see if it’s creating the noise. Warning: refitting a tumble dryer drive belt can be extremely difficult. They are very strongly tensioned and special tools are often needed to be able to force one back on, especially with a brand new belt.
Condenser dryer noises
Condenser tumble dryers have more parts than vented dryers and one which can cause noises is the small pump which pumps condensed water into the condenser drawer. If this pump becomes noisy it should be a different noise to the noise of the drum revolving and should continue even when the drum pauses when reversing. The condenser pump may run continuously during the cycle, or it may be designed to kick in and out intermittently during the cycle. If it develops excessive noise it may need replacing. Access may be available from the rear panel but some may need side panels and frontages removing.