Noise from 8-Bar filling valve (Megaflo)

[BenH]

In our sealed Megalo system, when hot water tap is used (say in bathroom shower) the megaflo is taking in some fresh water, I guess to compensate for the water used. The incoming water go via a pressure relief valve [most likely its this one: Heatrae Sadia 8 Bar Pressure Relief Valve - 95605893]. There is some low-level crackling/hissing noise from this valve (when the filling stops the noise disappears). Its evident that this valve is the source of the noise when I put my ear to it. TBH it must have been like that for many months/years and when airing cupboard door is shut you can only hear faintly. Also, there is small amount of scaling in the expected places on this valve which falls off when touched. Basically, is this a normal operation of the valve? Or is it time to replace it simply because of the noise?

 

[Ben-gee]

When was the last time you had your unvented cylinder and components serviced?
(Probably never been done, like most people)

Time to get a G3 registered plumber to service the system and clean/replace this critical safety element as part of that service.

 

[BenH]

I remember (few years back) calling a local plumbing firm (well known) asking about a service to megaflo system and they told me over the phone that it doesn't need any service... I'll look around for this service. BTW what does this service checks include? which parts? how often do you do it? Thanks!

 

[Basher]

I remember (few years back) calling a local plumbing firm (well known) asking about a service to megaflo system and they told me over the phone that it doesn't need any service... I'll look around for this service. BTW what does this service checks include? which parts? how often do you do it? Thanks!

From the HeatraeSadia website, an explanation of what they recommend is checked for a Megaflo:

 

[BenH]

From the HeatraeSadia website, an explanation of what they recommend is checked for a Megaflo:View attachment 86998

Thank you for this.