Originally Posted by
G4RHL
I don't find them noisy. Unobtrusive is in my case a more appropriate word. What are noisy, unless they have done something about them, are LightwaveRF 's unit. A dreadful noise. Mine went back and I went for Evohome. No regrets. It just of course may be your valves as mentioned by others and HR92 having more work to do. On two of my radiators I have had to use the adaptor and on one now the HR92 occasionally fires off. I suspect the valve is getting old and sticking causing more effort from the HR92 although it has not become noisier. I have replacement valves for all my radiators and just waiting for one original to fail and then I'll replace the lot. I am not sure there can be a silent unit as there is work to do but the noise is barely noticeable.