Supplementary Bonding

[Hagbard]

About 5 years ago I installed an en-suite shower room. At the time I didn't have access to the internet or this very helpful forum. Having read the sticky I am now aware that I made some unnecessary supplementary bonding and wish to confirm what if anything should be bonded in this case.
The electrical appliances are a power shower and a towel rail which is connected to the central heating but also has an immersion heater for summer use. The lighting is out of zone. All the water pipes (supply, waste and CH) are plastic, with the exception of the basin tap tails and the last 300mm of the shower supply pipes (which are not exposed anyway).
The shower and towel rail heater are both connected via fused spurs from the same ring main. Because they are both connected to the same ring main their protective conductors must already be connected. Do they also require to be supplementary bonded?

 

[Qedelec]

Just because they are connected to the cpc they are not necessarily excluded from suplementary bonding.
Because all conductors have a resistance there is a chance of a potential difference, so circuit that enter a bathroom should be bonded together.
Also eathing can intoduce a hazard into an otherwise earth free enviroment. Read all you can on the subject and you will then understand.

 

[Hagbard]

Also earthing can intoduce a hazard into an otherwise earth free environment.

I realise this, which is why I will be removing bonding that shouldn't be there, e.g. to the metal tap tails connected to plastic pipe supplying the basin.

Just because they are connected to the cpc they are not necessarily excluded from suplementary bonding.
Because all conductors have a resistance there is a chance of a potential difference, so circuit that enter a bathroom should be bonded together.

So having the shower and towel rail heater bonded is not introducing a hazard into an earth free environment, and may be necessary depending on the resistance of the cpc. I did bond them anyway, so I'll leave that alone.
Thanks for the reply Qedelec.

 

[Qedelec]

Well grasped and your welcome