heatmiser prt volt free switch

hello.
I'm trying to install a heatmiser prt volt free switch inplace of a drayton thermostat.
i have removed the old thermostat and tagged all wires up.
The wires were as follows
NEUTRAL =grey/blue wire
LIVE= brown wire
Call= brown/black wire.

When i come to wire the prt up
LIVE = L
NUETRAL=GREY/BLUE.
I dont understand were call wire goes does it go to a1 or a2.
I have wired them up in either of these and the heating does not come on when its called for.
Also the electronic time switch is set to on

So i am wondering
1. do i have the right unit.
2. do i need to put an extra wire in from somewhere
3. do i need to block earth off.

Also when i turn the electronic time switch off, the prt goes off and theres no power to it.

I have a ideal condensing combi-boiler isar combi.
the timing unit is a tempus 2 electronic timeswitch.
and the thermostat is a drayton

i thought it would be relatively simple to install as the website stated that if your stat has 2 wires not including earth, it should be straight forward swap.
As you can see i aint very good with electrical know how.
But any info would be appreciated
i have included the website with the wiring diagrams, as i cant copy the wiring diagram i want

http://www.heatmisershop.co.uk/images/new_prt_series.pdf

its the picture with page number 24 its the prt volt free switching.
MANY thanks

Permanent live to L & Neutral to N, from fused spur live, not programmer live.

A1 needs to be fed from heating out on programmer and A2 will then return to the Isar switched live, think it is L1 from memory, if not L2.

Can't see any reason you needed a volt free stat with an Isar

From what wires you have got you should have bought a battery operated room stat that just needs the call for heat wires (2) connected.

yep if you want to move it

ajb75 said:

yep if you want to move it

Click to expand...

Then we will ask you to move it back, it really is a plumbiing question, since they deal with stats and controls, we only put in the supply