We have a combi boiler, and recently when you run the shower after turning the hot tap off there is a large banging in the pipes. It only seems to happen with that specific tap (as far as I can tell).
I read online about water hammer, and I think that could be what's happening. I think I might need to turn of the water supply and drain the system, but I'm not sure if I need to turn the taps off/on in a certain order?
Best Answer
If you already have water hammer arrestors (you probably do, since this is the only tap that hammers), you'll need to turn off the water supply and drain the system to the lowest point in the system. You'll need to leave that drain point open for quite a while, depending upon the arrestors you have. When it's fully drained & the arrestors are all full of air again, just close the drain & turn on the supply again. No particular order to things.
Do expect quite a lot of sputtering at each tap the first time you turn them on.