Replacing Potterton EP2002 & EP2 Programmers

by Editor on March 29, 2014

The Potterton EP2000 and EP2002 has now been superceded by the EP2.

Check availability and prices for the Potterton EP2 Programmer.

I’ve seen quite a few of these Potterton EP2000 programmers on various jobs lately. They’re a large version of the old type mini minder central heating control timer and allow more space for the wiring connections. This seems to have been taken to extremes though and they have some spare terminals (ABCD) which allow for all of the control wiring to be done in the programmer rather than using the usual junction box wiring centre. I say extreme because there’s barely enough space for all the cables and it’s a squeeze to say the least!

Straight swap?
I’ve recently replaced two of these with the new model Potterton EP2 due to faulty sliders. The upgraded version is supposed to be able to do a straight swap and fit onto the same base. One difference between the EP2000 and EP2 is that the new version also has a screw at the base rather than just a plastic clip. Believe me, you certainly need that screw to help hold the programmer body to the base with a full load of cables packed in there. The new version doesn’t actually have interconnection terminals ABCD fitted so I guess this suggests that Potterton decided there wasn’t really space for all those cables after all.  There’s no facility on the old EP2000 bases to accept the bottom fixing screw anyway, so you’ll end up changing the base and it won’t be a 1 minute straight swap. More like a half an hour job.

Wiring Congestion
To help with the congestion problem, the EP2 could be mounted over a flush 2 gang box and any interconnections made behind the base.
One step backwards on the new version is the the plate type terminals aren’t as good as the original screw down type. The plates need lifting to get the screws under which can be a pain especially on the neutral and earth terminals where there are multiple wires to connect.

Wiring Connections
Links are required from N to neutral bal and also from L to terminal 5 which feeds the central heating side of things. Terminals 1,3& 4 serve the on and off connections for CH and HW as is usual with most modern programmer timers.

The EP2 is a good looking and functional central heating programmer. It has the usual two on/off periods for hot water and heating and advance. There is also a useful ‘ext’ setting which gives a 1 hour boost.
The EP2 is easy to set up and very user friendly.

{ 13 comments… read them below or add one }

KenP September 20, 2017 at 16:26

I inherited a pretty ancient heating and hot water system when I moved home (based on a Potterton Kingfisher II floorstander). It has worked well enough for the past couple of winters; but one of the Danfoss actuators failed recently. I decided to replace both the actuators and also to upgrade the elderly Potterton EP2002 programmer at the same time. Opting for convenience I bought an EP2, which I hoped would be a simple clip off – clip on job.

The problem I’m encountering is that, with the new programmer fitted, as soon as I turn on the power, the central heating kicks in. I can get the boiler to stop running by turning down the room stat; but the programmer itself has no effect effect (because no programmes are set, the sliders are both set to “off” and no lights are showing). As soon as I put the old EP2002 back, everything works as intended. The hot water side is fine using both programmers.

Is there something I’m missing or could it simply be a faulty EP2? I’d appreciate any advice you can give.

Hi Ken
You could check your programmer wiring against the diagram here
All the best

Editor August 28, 2017 at 14:47

Hi Jennifer. The top of the front panel locates into the top of the wallplate before hinging downwards. Then press the programmer firmly back to the wall until it locates into the large bottom clip. Some models will have no clip but screws instead. Turn those bottom screws clockwise to secure it back.
Note it’s important that the connection pins at the top of the programmer locate into the correct slots in the base. Best to check this before hinging down.

Jennifer August 20, 2017 at 18:07

I have the old EP2000 and have taken the front bit off to get to the wiring, like in the first picture of the slideshow above ^^ and can’t get it back on. Does anyone know how to put it back on to make the heating work again?

GEOFF August 1, 2017 at 12:52

Yes I believe it will.

stringer December 23, 2016 at 11:11

Hi Raymond
Just fitted a EP2002 timer removed ep2000 , can not get the pump to work, some thing wrong with my settings maybe at the start?

Lindsay Tosh December 16, 2016 at 12:22

The EP2 can be set to 3 times a day. It’s in section 11 of the installer’s guide at the top of column 2. The illustration shows 01 when it talks about gravity/pumped but this ID can be altered to 05 as per the table at the top of the next column. This is for replacing an EP6002 and gives three on/off per day. I discovered this only when I tried to set up the third period. It’s not at all clear.

Phil March 11, 2016 at 09:04

To replace an existing EP2002 with the newer EP2, for a layperson, is it as simple as getting the old one off the wall and putting the new one back in place, or do you need to open it up and wire according to the system?

Many thanks

LB January 17, 2016 at 12:41

The instructiondS for the EP2 very specifically say you can set them for two or three times a day but they don’t tell you how to change the settings! Typical Potterton.

Stephen kirton January 13, 2016 at 20:59

Hi. One of my sliders has gone missing mysteriously from my EP2002 will I need to replace the whole thing. Seems crazy for a small part if i do
Kind regards

Simon October 14, 2015 at 12:35

The slider has gone on my EP2002 programmer so am looking to replace it with this new EP2 model.
My question please is do I need an electrician to install this unit legally or is it something you thing a layman like myself could do?

Simon September 28, 2015 at 15:36

our ep2000 override button doesn’t appear to be working for CH and the rads come on when the HW comes on. Presume whole unit needs replacing?

Editor December 22, 2014 at 18:53

Hi Raymond
The Potterton EP2 will only have 2 programming periods and not 3. These are usually used for morning and evening timed settings.

Raymond November 26, 2014 at 18:08

Can you please tell me how to change the settings on my EP2 from 2 on/off to 3 on/off per day?

It is a mystery at present, I will be grateful for your advice.

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