Horstmann to Honeywell programmer help!

[pantsman28]

Hi Guys

I just can’t get my head around the wiring to replace my Horstmann 425 Tiara programmer to a new Honeywell ST6400C! Can any expert here help?

The central heating is gravity fed and is controlled by the hot water, hot water is independent but looking at the old wiring the hot water needs to be on with the heating...

Horstmann:

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• pantsman28
• 15 Dec 2008
• 1

Honeywell

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• pantsman28
• 15 Dec 2008
• 1

I have a junction box where the thermostat for the tank and room are connected.

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• pantsman28
• 15 Dec 2008
• 1

Picture of Junction Box, left to right:
1. Neutral (yellow)
2. Live (blue)
3. Hot water (red)
4. /
5. /
6. /
7. Heating (yellow)
8. /
9. ? (red)
10. ? (blue

 

[gas4you]

Unless you have a zone valve on the HW circuit, you will not be able to have heating on without HW.

 

[EliteHeat]

The instructions for the 6400 say that it is not suitable for gravity HW pumped CH unless part of a "C" plan system.

What have you got?

Oops, missed previous post.

 

[pantsman28]

I think I have a 2 port motorized valve fitted but its not a Honeywell V4043H shown in 'C plan' and have no idea which wires they are yet....

I take it a complete rewire in the junction box is needed first?

 

[namsag]

looking at wiring go and check your motorised valve it is probably 3 port.

 

[namsag]

As you look at picture of your tiara left to right its

EARTH
NEUTRAL
LIVE
HW ON (RED)
SPARE
HW OFF (BLUE)
CH ON (YELLOW)
SPARE
So match these up to honeywell instructions

the links that are in the SPARE terminals of the 425 are not needed in the honeywell

EDIT
Honeywell from left to right

spare or earth
neutral
live
1. HW OFF
2. CH OFF not required by you
3. HW ON
4. CH ON

 

[pantsman28]

Just checked it doent look like a 'Plan C' setup. What i thought was a 2 port motor... its a Drayton Mid position Actuator... more consistant with a Y-Plan

The badly blurred photo is of the drayton...

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• pantsman28
• 15 Dec 2008
• 1

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• pantsman28
• 15 Dec 2008
• 1

The motor (pump)
Black 2
Red 8
Yellow 1

Tank Thermo
Black 8
Red 9
Yellow/grey 10

Main supply
Red 8
Blue 2
Yellow 1

Drayton Mid position Actuator
Blue 2
Orange 8
White 6
Grey 10
Green/yellow 1

I just want to double check before I knock off the heating and power supply to the boiler (iIdeal Classic)

 

[namsag]

Dont touch anything in the junction box just change the backplates and wire as i have said . It will take 5 minutes

 

[pantsman28]

Dont touch anything in the junction box just change the backplates and wire as i have said . It will take 5 minutes

Just so i know what wires I am tracking from the junction box.

N. 2
L. 8
1.
2. not used
3. 9
4.

 

[pantsman28]

I will give this ago at the weekend, thanks for your help... I will keep you posted