A common problem with roller blinds is a broken chain.  Sometimes a chain will simply snap due to wear and tear or because the blind has been fitted too tightly inside the brackets, causing the linking pin to come loose and drop out.  If your blind has a continuous loop chain, you'll need to replace it with a new one, as the chain will be too short for repair.  However, if your blind has a standard chain, you will be able to repair it simply by using a joining link, obtainable from good DIY stores.

Here's how to do it.

Repairing your blind chain using a joining link

A joining link is simple enough to use in that you simply click the two ends of the broken chain into the link to make the repair.  However, unless you get the joining link in the correct position, it won't pass through the chain drive, and this will stop the blind from rolling up and down.  To ensure that the chain repair works properly, follow these steps:

1. Take the blind down from the fixing brackets on the wall.  Roll the blind up manually until it is back in the starting position.  
2. Now, lay the blind out on a clean surface, and take the chain drive fixing from the end of the roller tube.  This is a tolerance fixing only, so you should be able to pry the chain drive out quite easily using a blunt knife or flat-bladed screwdriver.  Take care not to damage or scuff the fabric of the blind as you remove the chain drive.  
3. Next, lay the chain out so that you can easily access both broken ends.  Take the joining link, and use it to click the two ends of the chain together.  Give the chain a shake to make sure that the ends are firmly secured within the link.  
4. Now, pull the chain through the chain drive to position the joining link.  To do this, use your thumb and forefinger at each end of the chain drive, and pull the chain through.  You want the link to rest below the fabric of the blind initially to ensure that it will travel through the chain drive smoothly.  
5. Replace the chain drive in the roller tube, and put the blind back into the fixing brackets.  
6. Check that the roller blind now works correctly, and if necessary, adjust the joining link's position to prevent it sticking, as described in # 4 above.

In conclusion

If your roller blind chain breaks, don't spend money on a whole new blind.  Just carry out a simple repair quickly and easily by following the guidelines set out above. If this method doesn't work, contact you local blinds installation company for more tips on repairs.