Head scratching heating.

I’ve been tasked with sorting the heating system at that big stately home… along with a heating engineer company who has about as much clue as I do.

Over the years the system has grown, changed, reduced, god only knows. And there’s no drawings… not many labels, and half the original cables are redundant, ( but not all removed)


So, to give me bit more understanding, I’m wondering if what has been written on switches are a standard terminology for big systems like this, or someone’s shorthand, only known in his head.


So my first question is, what might “VS” mean on a switch with neon indicator?

There are 2… VS1 and VS2 both mounted above the pump1 and pump2 switches… (there is a pump3 switch but no VS to go with it.)

Would that possible be Valve Switch???
They look like additions to the original pump switches.


I’m going to be opening everything up to trace what goes where…. And what can be taken out due to being redundant…




And if you can read the labels…. There is no “old boiler” anymore…. Not one that works anyway.

V would normally be for velocity in sensing terminology.
although it might not be true in this case.

Is it Valve Set? I take it that it is set in areas with a local thermostat so a call for heat would only heat that area. If that is the case there will be some remote manifolds and valve head actuators being more local to that area that signal back to the boiler to call for heat.

Valve solenoid? Maybe ....

Nice little bit of Pyro work in there, I realise that's no help at all though.

Dave OCD said:

Nice little bit of Pyro work in there, I realise that's no help at all though.

Click to expand...

The majority of the old wiring is pyro, with a bit of older conduit thrown in, and some modern rubbish T&E for good measure.

I’m hoping I get to use my old pyro tools at some point.


Looks like “VS” isn’t a standard thing to write on switches… so I’m just going to trace out everything out.

Below this room is the original boilers, the pumps and motorised valves… 3 of each, plus another valve for the water. (There is no third VS switch, so don’t know if they’re connected)

The 3 rightmost pyros go to the pumps, the 3 white FP200’s on the left go to the valves.

The 2 modules in the wylex box at the top left are some kind of timers…. So need to see what they do.



The 2inch trunking is packed full. It’s going to take time picking it all apart. They should have increased the size of it as things were added.
(I might still do that)


I’m also trying to convince the staff and owners that “if the heating or water call for heat, then the boiler fires up” isn’t quite as simple as that.

They think it’s running on too long…. Wasting oil. Just turn off the boilers…..