REPLACING AN EXISTING CH PROGRAMMER WITH HORSTMANN C17

[Biggles1947]

Advice wanted please. I have bought a new Horstmann Centaur C17 to replace an old Landis & Gyr RWB252 programmer but find the installation wiring diagrams unclear for a DIYer.

The boiler is a Boulter Camray 5 pumped system. The old programmer connections are pictured here:

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Can anyone please tell me how I should wire up the C17 (using the colours of the wires shown), including reference to a possible requirement for a link L - 2 that the Horstmann guide mentions?

Thanks

 

[denso13]

The C27 is the one you need http://www.horstmann.co.uk/files/5213/9938/3878/Replacement_guide_Wiring.pdf

 

[Biggles1947]

Thanks for your prompt and helpful advice. My only concern before swapping the C17 for a C27 is that the latter is listed on the Screwfix website as a 5-wire installation yet I only have 4 wires! Can you shed any light on this please?

 

[denso13]

Your existing wiring is ok (except the earth usage) and is a straight swap for the C27.

 

[Biggles1947]

Thanks again for your help. I shall be off to Screwfix on Monday to swap the C17 for a C27!