Boiler with water tank

With a normal working system I wouldnt expect to hear excessive noise. An unvented system shouldn’t be more or less noisy. My advice would be to look at replacing your system with a Combi Boiler. It will be a lot cheaper to have your system converted to a Combi Boiler. Rather than an unvented cylinder. Installation and running costs, short and long term would be better with a combi. If you have a large house. Then you can get large combi boilers to suit

Depending on size of your house and existing system? . An unvented cylinder Will always outperform a combi boiler. I would recommend a flush on the existing system then replace old vented cylinder with unvented. The noise with system could be down to a few reasons but most likely system requires chemical flush. This would always be done prior to install anyway. An unvented cylinder Will provide equal pressure at all hw outlets as long as incoming pressure to property is sufficient. A combi boiler will not.

Regarding the noisy ,unless you mean the tank in the loft as in the bull valve/float making being noisy? If you change to an invented cylinder there really shouldn’t be any quiter but would be more effective for your hot water and cleaner system as currently it’s open vented and unless your tank has a good cover it’s open to all sorts (it should have a lid/cover ) You could do away with the cylinder all together and fit a combi as it depends on your family size and how many bathrooms/showers you have for the size of combi required. As you system is 20 years old it may also need up grading to suit unvented cylinder or a combi as then it will be a pressured sealed system and as the pipe work is 20 years old you find some weak points in it (leaks etc as changed to a sealed system). Take care Gas Wright

The system you're thinking about getting installed could possibly be "less noisy" as parts / pipework would be replaced and thus become cleaner. However excessive noise occurs in dirty, untreated systems so I always recommend a powerflush and the correct top up of inhibitor. A powerflush would need to be carried out if you were thinking of having a new boiler installed anyway. Hope this helps. Kind regards Josh Browne PHGS LTD