Central Heating Isolation Switch

[IJWS15]

A puzzle.

We have a five year old house, conventional boiler (in kitchen) for pumped hot water and heating, no immersion heater. Thermostat in hall, controller in hot water cupboard below 2 pole fused switch. Connection box on floor of hot water cupboard. No switch / outlet at the boiler but there is a blanking plate with a choc block below it.

Last night I wanted to remove the thermostat to wallpaper behind it....

Turned off switch (in hot water cupboard) and instead of one live terminal in the thermostat (red) I had two (red and yellow) and the boiler was still running, although the indicator lights on the controller had gone out ! ! ! !

From current practice where am I likely to find the real isolation switch?

When I have some time I will trace all the wiring through. Wife didn't like me moving live wires to choc bloc so I could take the stat off the wall!

BTW we also have unlabelled 2 gang light switches which require two breakers to be pulled before they are safe.

I would assume that this was done by a pro but we did not buy the house new.

 

[jj4091]

Is your boiler in "the hot water cupboard" with the programmer? What lights does your 2-gang switch control?

 

[IJWS15]

The boiler is in the kitchen.

The 2-gang switch controls the landing light (2 way) and the hall light (2 way) - each fed from a different circuit.

 

[jj4091]

The boiler should have an easily accessible means of disconnection, if the blanking plate is being used as a junction box for the feed cable I would replace it with a 3A fused fcu, but you will need to establish exactly what the cable carries. The light switch issue is not a problem that is how you would expect it to be.

 

[IJWS15]

I have seen on this forum that any accessory which could not be isolated from one point had to be labelled as such - this switch is and isn't.

Will check the blanking plate and see if I can fit a fused switch.

 

[IJWS15]

Finally got round to looking for the isolator and found it (where I should have looked in the first place) it is on its own (almost) MCB on the CU!

However did find this - could qualify for picture of the week - installed by a professional (you cannot install these alarms yourself - well known security company!)



Faults:

The obvious white low voltage alarm cable sleeving on the earth wire for the alarm panel!

The live wire to the alarm is connected to the feed supply of the two pole switch, the neutral is connected to the load side. Result - when you turn off the switch all the neutrals on the central heating control circuits are live and this is why I was getting a live at the boiler connection with the switch off.

Now all is nearly as it should be just need to get a second switch for the alarm and install adjacent to this one - presently both on the same one.

 

[RF Lighting]

Not quite picture of the week, but you did make the hall of shame!

//wiki.diynot.com/electrics:hs:pic2