Around 90,000 boxes are potentially affected and Sky is offering a free replacement for anyone with the old box.
Sky says the issue comes not from a faulty part but from a fault in the way the box is assembled, and while performance is said not to be affected, and there is no safety risk, there could be a problem further down the line.
Sky's official response is as follows:
"We are providing a free replacement Sky+HD box to customers who have one from the first batch of boxes supplied by Pace. The reason for the swap is that Pace has identified a flaw in its manufacturing assembly process which might have affected some boxes from this first batch.
Pace alerted us to the assembly problem and has since rectified the flaw. Current box supplies are unaffected. While there were around 90,000 boxes in the first batch (versions 9F3001, 9F3002, 9F3003 and 9F3004), the flaw is likely to have affected only a small minority. However, we are providing a replacement box to all customers as a precaution.
What is the flaw? The issue relates to the way in which some of the boxes in the batch were assembled. In particular, it involves the internal cabling and the quality of the connections between components. This means that the build quality of a box that was part of this batch may not meet Sky's standards.
The assembly flaw does not involve a faulty component, such as a hard drive, or a software problem. Importantly, Pace has confirmed that the assembly flaw does not pose a safety risk. The box can continue to be used in the normal way, as installed by a Sky engineer, until we come to replace it.
The assembly flaw is not affecting the performance of these boxes. But, because some of these boxes may develop a problem over the longer term, we are choosing to replace them while they are still under warranty.
How does the replacement programme work? We have started calling the affected customers to fix an appointment for one of our engineers to come and install a free replacement box. Because of the number of boxes, it will take us about three months to contact everyone.
To make up for any inconvenience, we will give all affected customers three months' free subscription to our HD pack (worth £29.25) when we replace their box. In order to avoid problems in the future, we would encourage all affected customers to participate in the replacement programme while their box is still under warranty. All replacement boxes will come with a new 12-month warranty.
Can customers request a particular make of replacement box? Customers should tell us if they would prefer to receive a particular make of replacement box. While we can't offer a firm guarantee, we will do our best to accommodate their request.
How can customers tell whether they have a Pace Sky+HD box? The easiest way to find out is via the on-screen Sky Guide. Just press the ‘Services' button on your remote control, then select ‘System Set Up' followed by ‘System Details', and the manufacturer and version number of your box will be displayed."