If it's feasible, i would have 1 spur supply ing both, but if they're located far away from each other, then the second option may be your only option.

Why are two spurs needed ? - and what happens if you isolate one or other half of the  heating system and not the other half.  It may be cleaner with one fuse and 2 switches though the volt free contacts mean it should not be an issue in practice. Clear labelling though would be certainly be needed.

If it is more than 13A then 2 spurs side by side is not the brightest solution anyway.

When you say 'spur' are you correctly referring to a branch cable, or are you wrongly meaning a Fused Connector Unit - which is a frequent mistake committed by those who should know better?


Therefore, two spurs from one FCU would be alright.

aligarjon:

Some wholesalers list them as spurs and some as fused connection units.    I have always known them as and referred to them as  spurs,  Interesting to know where the term comes from. It was certainly used 30 odd years ago when i started out.

 

Same as "plugtops" I suppose; just a (silly) name that keeps being used.


I would think that a fused spur - the cable - was confused with the FCU because it is the FCU which has the fuse in it.



However, there is no indication in the OP as to what was actually being requested.

They are fused connection units,but have always called them spurs.Hz.

The customers are idiots and you are right, unless the link between the UFH is wireless, but that would be pointless anyway with both SFCUs in the same location.




Andy B.

Fused Connection Units (FCUs) were often referred to as Fused Spur Units (FSUs) in days gone by - because of their traditional use of creating a fused spur from a ring circuit (either to feed an appliance or a group of sockets). Obviously they can also be used in other ways too (not necessarily at the start of a spur) so Fused Connection Unit is clearly a better description, but rather like 'bulb' instead of 'lamp' it should be reasonably clear in context what's meant.

  - Andy.

Another vote for spur: fused spur and switched fused spur. I did ask for an FCU in the wholesalers some time ago and got a blank look. I have tried to move with the times but not everyone has kept up with me so I have one back to talking about spurs. 


All the dictionaries I look in refer to bulbs as the bright bit and lamps as the bits that hold the bright bit. So I am a bulb man. 


In response to the OP I would go with one spur.

There should be one SFCU supplying the boiler and generally the supply to all the other controls should be taken from the boiler.


I have worked on central heating systems where some idiot has run in two supplies, including several where the boiler has had a plug and socket to connect it that had a live pin on the plug when it was removed from the socket, because it was being back fed.


I actually went to one house a guy had just bought because the Building Society withheld part of the mortgage until various issues that the valuation surveyor had identified, the surveyor said repairs were required before an EICR was prepared to say it was now safe, as the electrical installation was potentially dangerous. One of the issues that resulted in the Building Society withholding part of the mortgage was that the surveyor had identified two supplies to the central heating system.


Andy Betteridge