How to connect Honeywell to replace Horstmann programmer (Ed.)

[Davy67]

Hi all - bit of issue on Christmas Eve
My Horstmann channel plus model H27 has stopped working.
I have been able to source a Holywell ST9400A this morning.

The Horstmann has following cables connected in
Clip position 5 black cable
Clip position 4 cable black cable
Clip position 2 cable 2 red cables ( 1 connecting L with slot 2 and 1 connecting slot 2 with slot 5 )
Clip position 1 cable - black cable

Live has 2 cable incoming live and cable to slot 2
Neutral has incoming neutral black and one additional neutral.

Cable is a black cable heading back over to boiler area all cores are black. Controller controls water on and heating on off.

The Honeywell ST9400A only has 4 pins - not sure how to connect.

Would anyone be able to advise how to connect the Holywell Programmer up assuming it can be used ?

Any help would be appreciated!

Regards

Dave

 

[RandomGrinch]

Horstmann H27XL...

ST9400

You currently have link wires between L and terminals 2 & 5 on the Horstmann.
These aren't required on the ST9400, as the links are made internally.

So connect...

N to N
L to L
Earth to Earth

1 on the Horstmann to 3 on the ST9400
4 on the Horstmann to 4 on the ST9400

It also appears that you have a black wire in terminal 5 - this is effectively connected to L, through the two link wires. Double check this is the case - if so, also connect it to L on the ST9400.

The black wires that are not neutrals should be oversleeved to denote they are switched lives.

 

[Davy67]

Hi RandomGrinch,

Many thanks for your answer and help - that has sorted and we have heating on !!

Many thanks and have a very Merry Christmas !

Kind Regards

David

 

[RandomGrinch]

Many thanks and have a very Merry Christmas !0000

Well done, stay warm and Bah Humbug!