The Potterton EP range of programmers is a bit more difficult than most to convert. But it has been covered before in this forum, once or twice 
. Below is an example of replacing one with a Hive. If you use the forum search facility, you will find others.
[URL='https://www.diynot.com/diy/threads/potterton-ep2002-to-hive-active-heating-and-hot-water-help.493791/#post-4045014']Potterton EP to Hive example [/url]
Please note though. You will need to be competent with electrical work and be able to understand what you are doing. With the Potterton EP some of the terminals don't have defined functions and would be selected for a purpose based on the preferences of the initial installer, meaning that your installation may well be slightly different from others on here. If in any doubt get a professional in to do it for you.
Once installed, you will be able to operate the 'smart stat' successfully by leaving the existing room thermostat in place and turning it up to its highest setting. However if you do wish to remove it, it needs to be decommissioned properly. It can't simply be disconnected, as this would leave the heating wiring 'open circuit' and the heating would not operate. To do this, it is necessary to trace the room thermostat cable back to its origin and note where each of the Red / Yellow / Blue wires go before disconnecting them. A wire link would then be inserted between the two terminals where the red and yellow wires previously originated from. The old thermostat and wire to it can then be completely removed.
. Below is an example of replacing one with a Hive. If you use the forum search facility, you will find others.[URL='https://www.diynot.com/diy/threads/potterton-ep2002-to-hive-active-heating-and-hot-water-help.493791/#post-4045014']Potterton EP to Hive example [/url]
Please note though. You will need to be competent with electrical work and be able to understand what you are doing. With the Potterton EP some of the terminals don't have defined functions and would be selected for a purpose based on the preferences of the initial installer, meaning that your installation may well be slightly different from others on here. If in any doubt get a professional in to do it for you.
Once installed, you will be able to operate the 'smart stat' successfully by leaving the existing room thermostat in place and turning it up to its highest setting. However if you do wish to remove it, it needs to be decommissioned properly. It can't simply be disconnected, as this would leave the heating wiring 'open circuit' and the heating would not operate. To do this, it is necessary to trace the room thermostat cable back to its origin and note where each of the Red / Yellow / Blue wires go before disconnecting them. A wire link would then be inserted between the two terminals where the red and yellow wires previously originated from. The old thermostat and wire to it can then be completely removed.
