Potterton EP2001 to EP2 - CH work independently??

[GillyMc]

Good Morning,

I hope someone can help. We had a Potterton EP2001 programmer and Potterton PTT2 Cylinder Stat (along with PRT2 Room Stat). The PTT2 Cylinder Stat failed and was replaced with a Drayton HTS3 and the Programmer with the Potterton EP2.

The Programmer front section was simply replaced and the back plate left as it was. The new EP2 has functionality to independently HW and CH; but it doesn't in reality.

The HW will heat independently and the CH and HW will work together, but the CH will not work on its own. The light comes on for the programmer on CH only, but it does not fire up the boiler unless the HW is also on.

Is this because the front panel has just been replaced - like for like - and the old EP2001 did not have the functionality to heat CH on its own? It's not a dealbreaker to not have CH on its own, given the cylinder stat, but would be nice to have the functionality if possible.

Can this be resolved?

Many thanks for any advice,
Gilly

 

[jackthom]

Your system sounds fairly old and most likely doesn't have any motorised valves similar to this one

Untitled

• jackthom
• 19 Dec 2008
• 18

If not, to get independent control of DHW and Heating would take a little plumbing and some rewiring of the controls.

 

[GillyMc]

Thanks jackthom,

It is an old system, but has served us well! It does have a motorised valve - Honeywell F-5. Would this still need rewire?

 

[jackthom]

Not familiar with that one but it does look like a 3 port valve if this picture is the same as yours. I would check the lever on the side hasn't been latched onto the fully open position and that it hasn't seized up.

When all power to the heating system is off you should be able to push the lever against the spring and maybe hear the motor turning as you move it. When released it should slowly return to the original position.

If the valve seems OK you need to check the setting in the EP2 for Fully Pumped/Gravity which should be set to Fully Pumped.

If that doesn't work, someone will need to take a closer look at the wiring and check out the valve.

 

[GillyMc]

Yes, it's 3 valve - pretty much identical to your pic, but F5 0535. Unfortunately the lever on mine is nowhere near as accessible as in your photo. I'll have a go at the above, will prob involve a mirror and strong flashlight!! The lever does move, that much I can tell now - just not what position it's in and whether it springs back. Will also check the EP2. Thanks again

 

[GillyMc]

OK, have checked both - the valve works exactly as you described and the EP2 is definitely set to pumped. Looks like it may well be wiring. Thanks for your help, jackthom.

This may seem like a silly question - but who would I get to look at this? If it's wiring - it's an electrician, but then I know a lot of sparkies won't touch heating/boiler related jobs if it's gas. Heating Engineer/plumber?

 

[jackthom]

Try for a local Domestic Heating Engineer/Plumber who should know how to wire the "Sundial Y Plan" .

http://www.honeywelluk.com/Documents/All/pdf/Sundial-Y-Plan-Reference-Guide.pdf


Check whether you still have the newer backplate that came with the EP2 as the old EP2001 backplate could turn out to be not entirely compatible.

With a bit of luck the controls you have should do the job with little or no re-plumbing.

 

[GillyMc]

Thanks jackthom,

Have spoken to Baxi/Potterton and the EP2 is not *quite* a like for like replacement for the EP2001 - hence reduced functionality... Good news is, as you suggest jackthom, with the new backplate and a little rewiring - we should be good to go!