A total of 77 per cent of the 486 staff in the London, South Eastern, South West, and Eastern regions voted for strike action, with 88 per cent supporting industrial action short of a strike.
The Unite union said the planned strikes, on 6 May and 8 May, are due to three disputes surrounding staff pay.
The first relates to a proposed pay increase of two per cent, coupled with a non-consolidated one off payment of £200 for the year April 2013 to April 2014, which Unite said does not keep up with the rise in the cost of living.
There has also been a dispute about pay in the South Eastern region since 2012 where Unite said EDF agreed to make up the difference between the pay in this group and London employees but has not done so.
The final issue Unite is concerned about is a “failure to pay” the Eastern revenue protection team, despite having signed an agreement in 2012.
The planned days of strike action would result in delays to fixing and installing meters, while revenue protection could be affected as employees dealing with customers who are allegedly stealing electricity would also be on strike.
The union also warned of further strikes unless EDF Energy’s management “sit down and negotiate in a constructive and equable fashion”.
Unite regional officer Kasab Onay said: “The argument is really quite simple. Those who make handsome profits for the company, our members, have a right to expect a pay rise that at least keeps up with the cost of living.
“EDF Energy should be ashamed in regards to the Easter revenue protection team because it signed an agreement with no intention of abiding by it.”
EDF Energy said the 2013 pay deal would be backdated to last April once it had been agreed, and that it was “fair and competitive”.
In a statement, EDF Energy added: “An identical offer was accepted last year by the vast majority of a much larger group of employees in the same part of our business – including those working in our customer service centres.
“We have been in continuous talks with Unite and other unions for more than 12 months to agree the pay increase and we remain open as always to meeting employee representatives.”