Am I able to fit my own unvented hot water system in my house?

Question from John via email:
I’m considering fitting an unvented hot water system in my house and I keep reading that you need to be a “competent person” and must inform building control etc. What is the position when fitting it in your own home? I consider myself to be competent and understand the implications relating to pressure vessels.

Response from Martyn Bridges, director of marketing and technical support at Worcester, Bosch Group:
This is an interesting question and one that has been “doing the rounds” for a few years. However, since the introduction of the competent persons scheme I believe this is now a little clearer. My understanding of the situation is:

To be a member of a competent persons scheme, and as such be able to self-certificate the installations of controlled services such as unvented hot water storage cylinders, then you are required to demonstrate your competency by holding the necessary qualification in the installation of unvented hot water storage systems.

It is permissible to not hold this qualification, not to be a member of a competent persons scheme and still install unvented hot water storage cylinders providing you are competent. The condition of this however is that you must inform building control who will inspect every installation you notify them of for compliance.

The downside of the second option is that the expense of engaging building control to inspect every job is significant, if you are installing a “one off” then it is probably more economic not to join a scheme, if you are regularly installing unvented hot water storage cylinders then it would pay to join a scheme.