How to Replace a Vertical Blind Tilt Chain or Control Mechanism
Updated: Aug 29
If the chain at the side of your vertical blind has snapped, disappeared or no longer turns the vanes, you don't necessarily need to replace the complete headrail.
In many cases, you can replace just the tilt chain. If the control mechanism itself is broken, that can also usually be replaced separately.
The first job is working out which part has actually failed.
Which Vertical Blind Chain Are We Talking About?
Vertical blinds can have several different cords and chains, so it's easy to order the wrong part.
This guide is specifically about the operating chain hanging at the side of the headrail that rotates or tilts the vertical blind vanes.
It is NOT about:
The bottom chain connecting the fabric vanes
The cord used to draw the blind open and closed
Replacing the internal carriers or trucks inside the headrail
The tilt chain normally moves only a relatively short distance as you operate it. Its job is simply to rotate the vanes through approximately 180 degrees from one closed position, through open, to the opposite closed position.
Has the Chain Broken or the Mechanism Failed?
Before ordering a complete replacement mechanism, inspect the existing blind.
If the mechanism previously worked correctly and the chain has simply snapped or gone missing, replacing the chain alone is normally perfectly adequate.
There's no need to replace a working mechanism just because its chain has broken.
A replacement mechanism is more likely to be required if:
The chain moves but the vanes don't turn
The mechanism slips when operated
The sprocket no longer grips or drives correctly
The casing is cracked or physically damaged
The mechanism jams or fails to rotate properly
If the chain and mechanism appear to work but the vanes still won't turn correctly, see our separate guide to Why Your Vertical Blinds Won't Turn and How to Fix Them before replacing parts unnecessarily.
What Chain Do I Need?
The type commonly used for this application is No.6 vertical blind control chain.
Replacement No.6 chain is available in finishes including:
White plastic
Silver/metal
It can be purchased by the metre and formed into a loop using a suitable chain joiner.
This means you aren't normally restricted to buying a particular ready-made loop length.
How Long Does the Vertical Blind Tilt Chain Need to Be?
Unlike the cord that draws a vertical blind across the window, the tilt chain doesn't have to travel the width of the blind.
It only needs sufficient movement to rotate the vanes from one direction to the other.
Therefore, there is generally no benefit in fitting an unnecessarily long tilt chain.
It should be long enough to operate comfortably while also being installed with the appropriate child-safety arrangement and in accordance with the relevant blind-safety requirements.
Replacing the Tilt Chain Only
If the mechanism is working correctly and only the chain is damaged, you can replace the chain without replacing the complete control mechanism.
Remove or access the tilt mechanism sufficiently to fit the new No.6 chain around its sprocket.
Once the new chain has been correctly seated around the mechanism, form the operating loop using the appropriate connector.
Before refitting everything, operate the chain in both directions and make sure the mechanism turns smoothly.
If your original blind had plastic chain, this is also an opportunity to upgrade to metal chain if you prefer its appearance and feel.
Alternatively, there's nothing wrong with replacing like-for-like with white plastic chain.
When Should I Replace the Complete Tilt Mechanism?
Replace the complete Vertical Blind tilt mechanism if you've established that the problem is inside the control unit rather than simply a damaged chain.
Typical symptoms include slipping, damaged sprocket teeth, a cracked casing or a mechanism that no longer drives the tilt system correctly.
Before ordering, compare the replacement with your existing control unit.
Standard vs Vogue Vertical Blind Tilt Mechanisms
Not all vertical blind control mechanisms are the same.
Two types you may encounter are standard and Vogue systems.
One useful visual clue is the shape:
Standard mechanisms have a more square-sided profile.
Vogue mechanisms have a more curved profile.
Comparing the shape of your existing mechanism with clear product photographs before ordering can help you identify the correct replacement.
Left-Hand or Right-Hand Control – Check Before Ordering
This is particularly important.
Vertical blind tilt mechanisms can be supplied for left-hand or right-hand control, so check which side of your blind you want the operating chain before ordering the replacement mechanism.
With some simple left-stack or right-stack blinds, this may be less critical because the headrail can potentially be turned around to place the controls on the required side.
However, it becomes particularly important with a split-draw vertical blind, where the vanes open from the centre towards both ends.
With a split draw, make sure you order the correct left- or right-hand mechanism so the operating controls remain on your preferred side.
How Is the Vertical Blind Tilt Mechanism Held in Place?
On many vertical blind headrails, the control mechanism is retained using a star washer fitted over the tilt rod.
This is a small component, but removing it can be one of the fiddlier parts of the job.
A thin flat screwdriver and a pair of pliers can normally be used to carefully work the star washer from the rod.
Take your time and try not to damage it unnecessarily.
Can I Reuse the Star Washer?
Potentially, yes.
If the existing star washer is still in reasonable condition after removal, it may be possible to reuse it.
The teeth can sometimes be carefully tapped flatter again before the washer is refitted onto the tilt rod.
Obviously, if the washer is badly distorted, cracked or damaged, replacement is preferable.
A Useful Trick for Refitting the Star Washer
In theory, fitting this type of retaining washer is easiest with the appropriate specialist installation tool.
For somebody repairing a single blind at home, buying a specialist tool that may rarely be used again isn't particularly practical.
Fortunately, there's a simple workaround.
A screwdriver handle/end with the removable bit taken out can sometimes be used as a basic fitting tool.
The important point is that the hole in the end needs to be larger than the tilt rod.
This allows the tilt rod to enter the hollow centre while the outside of the screwdriver end presses evenly against the star washer.
You can then carefully push or tap the washer back into position.
It's a simple fitter's trick that can save buying a specialist tool for a one-off repair.
Replacing the Complete Tilt Mechanism
The exact arrangement varies slightly between headrail systems, but the basic procedure is:
Remove the vertical blind headrail from its brackets if necessary for safe and convenient access.
Remove the appropriate end components to expose the control mechanism.
Carefully remove the star washer retaining the mechanism/tilt rod.
Disconnect and remove the damaged tilt mechanism.
Compare the old and replacement mechanisms to confirm compatibility.
Fit the replacement mechanism in the same orientation.
Refit the tilt rod and retaining star washer.
Reuse the existing chain if it's in good condition, or fit replacement No.6 chain.
Operate the chain slowly and check that the vanes rotate correctly in both directions.
Refit the headrail and test again.
Don't force the mechanism if the vanes won't rotate normally. If something is jammed elsewhere in the headrail, forcing the chain can damage your new control mechanism.
Should I Reuse the Existing Chain?
If the chain is in good condition, there's no reason it can't be reused with a replacement mechanism.
If it has become brittle, dirty, damaged or discoloured, however, replacing it while the mechanism is already being worked on makes sense.
You could also take the opportunity to change from plastic to metal tilt chain if preferred.
What If My Vertical Blind Still Won't Turn?
If you've replaced or checked the mechanism and the vanes still don't rotate properly, don't immediately assume the new mechanism is faulty.
The problem could be elsewhere in the headrail.
For example:
One or more carriers may be damaged
The carriers may be incorrectly aligned
Something may be obstructing the tilt system
The headrail may have an internal fault
Our guide to Why Your Vertical Blinds Won't Turn and How to Fix Them covers these problems in more detail.
What About the Cord That Opens and Closes the Blind?
That's a different repair.
The cord used to draw the vanes across the window operates the traverse system inside the headrail.
Replacing or re-cording this system is considerably more involved than replacing the tilt chain.
This guide therefore deals only with the chain and mechanism responsible for turning the vanes, not drawing the blind open and closed.
Quick Troubleshooting Guide
Problem | Likely cause | What to check |
Tilt chain snapped | Chain failure | Replace No.6 chain |
Tilt chain missing | Chain lost/removed | Fit new chain and joiner |
Chain moves but vanes don't | Mechanism or internal tilt fault | Check mechanism |
Chain slips | Worn sprocket/mechanism | Consider replacement mechanism |
Mechanism casing cracked | Physical damage | Replace mechanism |
One/few vanes don't turn | Carrier/alignment problem | See turning troubleshooting guide |
Several/all vanes jam | Headrail/tilt system fault | Diagnose before replacing mechanism |
Unsure which mechanism | Standard vs Vogue | Compare square/curved profile |
New control needed | Left/right configuration | Check required control side |
Split-draw blind | Control side particularly important | Order correct left/right mechanism |
Child Safety
A looped operating chain should always be installed with the appropriate child-safety arrangement.
If you're replacing an existing chain, don't remove or bypass a safety device simply to accommodate the new chain.
Choose an appropriate chain length and ensure the completed installation complies with current blind-safety requirements.
See our dedicated Blind Cord & Chain Child Safety Guide for more information.
Before Ordering Parts – Check These Five Things
Before buying a replacement chain or mechanism, check:
1. Is it definitely the tilt control? We're dealing with the chain that rotates the vanes, not the bottom chain or traverse cord.
2. Has only the chain broken ? If so, you probably don't need a new mechanism.
3. Which mechanism do you have ? Compare the shape of your existing unit – particularly standard square-sided versus curved Vogue types.
4. Which control side do you need ? Check whether you require a left- or right-hand mechanism, particularly with split-draw blinds.
5. Is the rest of the headrail working correctly ? Don't replace the control mechanism if the real problem is a jammed or damaged internal carrier system.
A Broken Tilt Chain Doesn't Mean You Need a New Blind
A snapped vertical blind tilt chain or damaged control mechanism can make an otherwise perfectly good blind unusable.
Fortunately, both components can normally be replaced separately.
If the chain alone has failed, fit new No.6 vertical blind chain and retain the existing mechanism.
If the mechanism is genuinely damaged, identify the correct standard or Vogue replacement, check whether you need left- or right-hand control and replace the unit.
And don't be put off by the star washer.
It may be the fiddliest part of the repair, but with a thin screwdriver, pliers and a little patience, it can be removed – and that screwdriver-with-the-bit-removed trick can make refitting it considerably easier.
Comments