No, it does not seem to be water hammer at all. Water hammer, according to Wikipedia, is a pressure surge or wave resulting when a fluid in motion is forced to stop or change direction suddenly (momentum change). Water hammer commonly occurs when a valve is closed suddenly at an end of a pipeline system, and a pressure wave propagates in the pipe.


In my case there is no valve being closed. In fact, when the radiator valve is closed all noise ends.

I have put my ear against the boiler while the pump is working and I can hear the same noise. There seems to be also a fan working at the same time as the pump is.

I strongly believe now that the noise at the radiators is the pump/fan noise.

It seems that these new boilers work with a higher pump speed which leads to higher water flow.

According to Worcester tech support there is no way to lower the pump speed in my boilers (which are supposed to be good quality and expensive ones).

I am willing to change the boilers.

Are there other good quality boilers that will not give me the same problem. Perhaps by allowing a reduced pump speed when needed?

Would a plate heat exchanger, with the same boilers solve this problem?

If so, what does it entail to have a plate heat exchanger installed?


Thanks,

Antonio