I just bought as new house and the pipes make a noise. I looked at the pipes in my basement and didn’t see any hammers, so I don’t think it is a water hammer. Could that hammer be in the walls?
Hammering noises are usually – but not always caused, by non cliped or strapped pipes and usually happens when appliances such as washing machines or simililar appliances are used as they have solenoid valves that slam shut causing the water flow to be rapidly stopped resulting in a hammering noise travelling through the water pipework. Check for adequate and properly fitted pipe support clips or brackets and if all else fails get your local Plumber to fit a water hammer arresting device to the pipeline.