Hissing and Water Running Noise From Central Heating All aspects of plumbing questions and answers, help, tips and information

[DIY101]

Hi All,

I have been tearing my hair out trying to resolve this constant hissing(sounds like someone has left a tap on) noise that is coming from my central heating. I can hear this noise in all rooms upstairs. I have recently installed a combi-boiler (replaced a conventional boiler). In order to resolve this issue I have done/checked the following:

- Bled all rads upstairs (have done this a few times)
- Had a look under the floor boards and put my ear to the pipe (no noise at all)
- Reset the boiler
- Turned the water off throughout the house to see if hissing noise stopped
- Turned the central heating off completely
- Turned the central heating for upstairs off
- Have taken a number of TRV's off to see if that made any difference
- Checked the loft but nothing obvious identified
- Put my ear against each rad to see if the noise was coming from them - no luck
- Ensured all Rads upstairs are fully on
- Tried switching all rads off and then switching them back on one by one - no luck

Can anyone recommend anything else I can do to try and stop this noise?

Thanks

[collectors]

Hi, i am not joking, but any chance you might have tinnitus as this is the same noise i hear all the time when at home & its quite. Try covering both ears with your hands & if the noise is still there, this is what you might have.
Just a thought.

[DIY101]

Hi - nope its not that.