Sunvic TLX7501 digital stat

[Jo_24679]

I have recently bought a Sunvic TLX7501 digital stat to replace the old Sunvic 2259 unit. I have wired the live wires to points 3 and 2 on the stat unit leaving point 1 blank. The negative wires have been joined and then taped. The Sunvic technical helpline confirmed that the 2 wires have been connected to the right connectors but still the unit doesn't send a signal to the combi boiler. The room stat does click in and out and will display a gas symbol....just nothing actually happens. Has anyone else had a digital stat that just doesn't repond? Any help you could give would be great.
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moderator

Jo_24679, please note 20 , your post has been split

 

[Slugbabydotcom]

Is there continuity between 3 and 2 when the light is on and vice versa if so the unit is working fine and the fault is elsewhere

 

[Jo_24679]

Hi - I'm not sure what light I should be looking at. There are no internal lights on the unit.

 

[Slugbabydotcom]

The room stat does click in and out and will display a gas symbol....

Sorry my mistake ... When I said light I meant 'gas symbol' that indicates that the connection is made.
You didn't specify what combi boiler it is connected to, or what voltage it is switching. Most combi's use low voltage for room stat connections and the lowest this will switch is 24v. I don't know why but its there in the spec.