Do you have any experience installing water based heating systems?

If you have not installed a water based heating system you could reply like this: "I have not had the chance to install a water based heating system although I do bring some knowledge in that area through research and a basic understanding of the plumbing concepts required for the job."

If you do have experience installing water based heating systems you should talk about how many you have completed. Be sure to display some of your knowledge on the topic.