Hi,
I am having a new kitchen installed. I had several people around to give quote. Some said they needed to bond the water ppipes back to the consumer unit and some did not think it was needed. Also one of the contractor said he also need to bond the gas pipe back to the consumer unit. Which is correct?

I will assume by the use of the term "Consumer Unit" that you reside in the UK or British Isles.

I will say the one contractor that mentioned bonding both the water and gas is the one on the ball.

Ask him to cite the IEE regulation and/or the British Standard that requires equipotential bonding.

This should include:

* Water Pipes
* Gas Pipes
* Oil Pipes
* Central Heating
* Metallic Ventilation Trunking
* Exposed Parts of Building Structure
* Lightning Conductor
* Any other Metallic Service

More importantly, once you are more familiar with the regs, then go back and ask the contractors that did not mention bonding if they included it in their bid. And ask the ones that did not "think" it was needed, why? They should not need to think, they should know without a doubt.

Here in the USA, all metal systems in a building need to be bonded back to the grounding system. This is to keep any exposed metal system that may become energized by a short or ground fault at Zero potential, and will allow any voltage to "drain" off, and allow the overcurrent protection device (circuit breaker or fuse) to trip.

This is similar to IEE Regs.