Appliances generally last for 15 - 20 years, especially when maintained properly. Proper maintenance actually reduces the incidents of faulty functioning considerably.

When a household appliance stops working, you have two choices. You can either repair the appliance or replace it. To take the right decision several factors need to be considered.

First and foremost check up on the age of the appliance and its warranty period. If the warranty period is still on, the repair may cost nothing or less than what it would have cost otherwise.

Assuming that the warranty period is over and that repair is going to be costly, then you need to analyze a few points. You should begin by getting an estimate of the cost involved.

If the cost is about 50% or less than that of a new appliance - then it is worth getting the repair done. 

Otherwise it would make more sense to just upgrade to a newer model. A very old appliance may present you with the problem of hard-to- find spare parts.

Newer models are generally energy efficient. This will translate into considerable savings and over the years the cost will be justified.