Honeywell zone valve

[Fallout]

What is the white wire for on a Honeywell zone valve 2 port valve. It makes it 6 core.

 

[stem]

Are you sure it's actually a wire and not just a central filler core. Often used with cables having 5 wires to keep them in place.

 

[MJN]

It is used in conjunction with a C-plan setup, for gravity DHW and pumped CH.

It enables a DHW call for heat to be satisfied without causing the pump to run if there isn't also a demand for CH.

 

[stem]

Not come across one of those for a long time.....probably decades.....In fact I even forgot they existed.

A imagine a replacement might be tricky to find though these days. Most versions of the V4043H don't have the 6th white wire anymore.

 

[MJN]

Yeah it'd be pretty old school. Before we were born most likely let's just say...

If @Fallout doesn't have a C-plan setup but rather S-plan then obviously they can just terminate the white wire safely and tuck it out of the way.

Note that the wiring diagram looks like it isn't quite accurate (or rather detailed enough) with the part numbers and that it looks like it is the V4043H1080 (1") and V4043H1106 (28mm) variations that are the 6-wire versions.

 

[ianmcd]

Not come across one of those for a long time.....probably decades.....In fact I even forgot they existed.

A imagine a replacement might be tricky to find though these days. Most versions of the V4043H don't have the 6th white wire anymore.

View attachment 250091

No still readily availabe, as already said safely isolate the white wire if not using

 

[Terrywookfit]

28mm valves have 6 wire head as standard.

 

[Fallout]

28mm valves have 6 wire head as standard.

Thanks is that because 28mm is more likely to be on a gravity hot water system?

 

[Terrywookfit]

Thanks is that because 28mm is more likely to be on a gravity hot water system?[/QUOT I have not fitted a C plan for 30 years.

 

[MJN]

Thanks is that because 28mm is more likely to be on a gravity hot water system?

Yes. The pressure differential created by heating the water is relatively small (and certainly when compared to that from a circulating pump) and the flow rate for any given pressure differential is proportional to the radius of the pipe hence the need for large(r) pipes.

 

[Terrywookfit]

A 28mm valve is far more likely to be used on a heating zone than a gravity one nowadays.