Kmart champions 'low prices for life” – just don't expect some of its products to last longer than a few years, let alone a lifetime, warns Consumer NZ.

Consumer NZ product test manager Dr Paul Smith decided to take a $29 Kmart blender for a spin after reading a warning in the instruction manual that its maximum operating time was one minute "to prevent damage to the electric motor".

He used it to make his daily smoothie and within seven days, the blade worked loose from its housing and green-black liquid dripped from the base of the jug.

"A blender showing signs of failure in its first week is concerning, but what's worse is Kmart's failure to offer a repair. The blade is removable for cleaning, so it would be very easy to replace. But there are no repair parts on offer, so at the slightest sign of failure it needs to be tossed," says Dr Smith.

"For companies focused on low prices such as Kmart, it's cheaper and easier to replace an entire product rather than fix it.

'The few that fail within warranty hit Kmart's bottom line, but the majority that hang on just a bit longer don't cost the retailer a cent. There's no incentive to make products that perform beyond a year or two."

The $29 blender Photo: Kmart.

Consumer NZ's latest survey found 54 per cent of respondents agreed that the warranty period was a good indication of how long a product will last.

A replacement part for the blender was requested from Kmart customer service and the response was, 'If your blender is less than 12 months old, please take it along with your receipt to your local Kmart store for an exchange or refund.”

Consumer NZ previously contacted Kmart to see if they could get spare parts for an Anko kettle. It responded: 'We do not offer spare parts or warranty repair service [for any kettles sold] at Kmart. It is not possible to do so, within our everyday low pricing model.”

Dr Smith says, the consumer advocacy group thinks manufacturers and stores that sell cheap, unsupported, built-to-fail appliances have a responsibility to clean up their act.

'Last year, the government announced electrical and electronic products as one of the six priority product classes that will get a mandatory product stewardship scheme.

'This means everyone making, selling and using an appliance will have to take some responsibility for dealing with it when it's no longer wanted, or dies and becomes 'e-waste'," says Dr Smith.

"Through our Built to Last campaign, we are challenging manufacturers to make more durable and repairable appliances and to provide spare parts at a reasonable cost.”

He says they are also changing the way they conduct testing to introduce 'reliability scoring” to help consumers be informed about durability when purchasing a product.