I changed yesterday from Scottish Power to EDF to price fix until April 2015
Prices are not going to go down so if you can fix it’s a good idea.
You need to factor in two things
1. How much your bill will be when the fixed price period finishes
2. Is there an early exit penalty? If not then you can always jump to another tariff/supplier
Having had a look at where energy prices are going you need to get in there now and fix with a provider before their prices jump.
EDF have a four year price fix that might be worth looking at which is a little more now but in four years will be a good rate