Your opinion please:
When I flush the toilet or use a sink tap on the same wall you can hear two or three loud thuds (I think it’s called hammering). I turned off the water stop tap and drained all the water out, which seemed to reduce, but not eliminate, the noise for a while. So, I called a plumber. He held a few pipes (to see if they vibrated – no) and listened at various places for the noise, but eventually said several things could be done, none guaranteed to work, so “just live with it.” Is there a solution? Am I right in thinking this plumber just didn’t want the job? Any help appreciated.

Hi, thanks for trying to help. So:

- Plumber wasn't into details, did mention a toilet washer that he wouldn't fit
- Yes, after refilled
- Tap is monobloc, washer type unknown
- Banging is with either tap or toilet
- Pressure very good
- Mains, I think
- Combi boiler (plumber said this can contribute to problem but didn't explain why)
- Monobloc tap - bangs on hot or cold
- FYI toilet is dual flush syphon mechanism not traditional ball cock CORRECTION looking at pictures it's more likely a bottom-entry fill valve type

ADDED - Also, just checked the shower on the same wall also thuds, but not as loud

Vaillant TURBomax Plus 824/2E

I have the installation and servicing and instructions for use manuals - can't immediately see anything about shock arrestors, what am I looking for?

ADDED - Just reading a few articles on arrestors, am I right thinking they have to be attached to tap/toilet/shower pipework? Most of my pipes are behind fully tiled walls. Can an arrestor be fixed to the boiler? Can that solve the problem?

Also, there is mention of combis with water meters.  I'm on a water meter - significant?

ADDITIONAL DEVELOPMENT
Having seen some other suggestions, I tried turning the stop valve lower and with no improvement I thought I'd drain the system again - this time including the garden tap. On refilling, the thumping has stop except with the sink tap I can hear a very faint (barely audible) tapping noise, just the one, from around the same place as the thuds. That I can live with as long as you don't tell me it will in the long run cause damage/further problems.

SOLVED
Forgot to include the downstairs toilet and sink in the draining - repeated - and NO noises at all. Thanks for your help; I will keep shock arrestors in mind if the problem reoccurs.