Just opened mine (still have the instructions) There's a screwdriver slot on the bottom, viewed from the front it is vertically below the Time Set buttons. Took a bit of pressure tho, not been opened for 22yrs!
chilly house
January 2012
EP2000 has slot right under press it with small screw driver you will see cut out
ltd
January 2012
I can answer this question...
Potterton EP2000 (old brown version) cover removal?
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