This was emailed to me, thought it better to put it here:
I'm at my wits end trying to change a CH programmer (and her indoors is getting cold!).
I want to replace a Randall 102 with a Sunvic 207 XL. The boiler is an Ideal Elan 2. There are no room stats - just a bog standard system. CH is switched off in summer months by use of a summer valve in the airing cupboard so that hot water only is supplied.
The instructions are somewhat confusing and don't seem to relate exactly.
Current wiring is:
Live to 6 with a jumper from there to 3.
Neutral to boiler and 5.
Earth to boiler and programmer.
2 (live) goes up to boiler.
There is nothing from or to 1 although the Sunvic instructions state that the old 1 corresponds to new terminal 3.
According to instructions everything else seems to fit into place but I am puzzled by the jumper and by the missing cable to/from terminal 1.
Also should the unit be set to pump or gravity?
The programmer doesn't know what it's switching on, as there's no way to control the system other than the manual valve. Therefore only one channel is used - boiler on and off. That's why term 1 isn't used.
The link is just there to supply a live for the output terminal - it's internal in the new programmer.
Until you add motorised valve(s) to your system you won't be able to control it any better.
I'm at my wits end trying to change a CH programmer (and her indoors is getting cold!).
I want to replace a Randall 102 with a Sunvic 207 XL. The boiler is an Ideal Elan 2. There are no room stats - just a bog standard system. CH is switched off in summer months by use of a summer valve in the airing cupboard so that hot water only is supplied.
The instructions are somewhat confusing and don't seem to relate exactly.
Current wiring is:
Live to 6 with a jumper from there to 3.
Neutral to boiler and 5.
Earth to boiler and programmer.
2 (live) goes up to boiler.
There is nothing from or to 1 although the Sunvic instructions state that the old 1 corresponds to new terminal 3.
According to instructions everything else seems to fit into place but I am puzzled by the jumper and by the missing cable to/from terminal 1.
Also should the unit be set to pump or gravity?
The programmer doesn't know what it's switching on, as there's no way to control the system other than the manual valve. Therefore only one channel is used - boiler on and off. That's why term 1 isn't used.
The link is just there to supply a live for the output terminal - it's internal in the new programmer.
Until you add motorised valve(s) to your system you won't be able to control it any better.
