main combi 30 he timer wiring problems

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i have a main combi 30 he with no timer fitted, i bought a timer and wired it in as follows
live and neutral to terminals 1 and 2
the 2 blacks to terminals 3 and 4
and nothing on terminal 5
But the heating is not coming on, i have hot water. i can hear the switch clicking but the heating does not come on .any help would be great.
 
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You have only given half of the story. What make / model is the timer and what terminals at the timer have you connected to what terminals on the boiler.
 
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yes this is the wiring of my boiler. but the harness for the timer does not plug in there
 
If it comes with a harness and plugs straight into the special connector, then the wiring should be correct as it stands, if you have the correct timer. Your boiler isn't listed on the data sheet.


Boiler terminal 1 = programmer terminal 2
Boiler terminal 2 = programmer terminal 3
Boiler terminal 3 = programmer terminal 1
Boiler terminal 4 = programmer terminal 4

Is there still a link between 1 & 2 in the diagram below?

 
OK, so looking at your photo, terminals 1 & 2 on your timeswitch are the Live and Neutral. I can't see any polarity shown on the unit, so unless the instructions say otherwise, it doesn't matter which way around they are. Connect them to L & N

The other terminals (3,4 & 5) are a changeover contact, so connect 5 & 3 to the terminals 1 & 2 at the boiler as shown below, and remove the link.


If the timer works in reverse ie 'on' is 'off' and vice versa, then connect 4 & 3 to terminals 1 & 2 at the boiler instead.

If you have incorrectly connected the timeswitch previously, there is a possibility that you many have damaged it and / or the boiler.
 
i just tried 5 and 3 and in worked in reverse, you said try 4 an3 if this is the case do you mean 5 and 4, because it was 3 and 4 in the first place
 

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