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Plumberpro, Home Appliance Technician
Category: Appliance
Satisfied Customers: 634
Experience:  Heating and hot water heating appliances experienced
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My customer has a worcester greenstar 28I junior condencing

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My customer has a worcester greenstar 28I junior condencing boiler and i have been asked to fit a Honeywell CM900 wireless RF Chronotherm. The incommig power supply goes via a 5 5 amp controlled fuse switch, the supply out from this switch splits, live to the cm900 unit and neutral splits one to the cm900 unit and one to the boiler neutral connection. there is a live outlet point on the cm900 unit, the cm900 unit has a further two outlets showing to be connected to the boiler marked A&B. A IS DESIGNATED TO CONNECT TO POINT t1 ON THE BOILER AND B IS DESIGNATED TO CONNECT TO T2 ON THE BOILER.
The boiler has 4 connecting points designated FR, FS, NP LP. PLEASE CAN YOU CONFIRM WHAT I ATTACH THE A&B cm900 outlet to on the bolier ?

Plumberpro : Hi . It is Lr, Ls , Ns and n. This is l return , live send and neutral send. ls goes to on A . Lr goes to C. The programmer dosnt need neutral so you only need those two wires, basically an in and out via a switch.
Plumberpro : Sorry , that was for the non wireless one, for the wireless one live and neutral to the n and l, the from the boiler Ls to A and Lr to B . By the way it should be a 3amp fuse in the fused spur.
Plumberpro : so yes to answer your question you attach A and B to the boiler . You can also bring the live and neutral from boiler aswell if you need to .
Plumberpro : If satisfied with your answer can you please give a positive rating , thanks ,Toby
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