Fitted an extender stay around xmas, haven't been able to use it yet as the supplied hose had a leak and I'm still waiting for a replacment, but that's another rant.... Last month it's started zinging (as it were) when gas appliances running, I'm pretty sure it's the extendastay tee the noise comes from. One gas ring say, no noise, two some noise louder on three and if the furnace or water heater are run noise. If we get up to everything running it seems to shut up. Tryed the reset game yesterday and even wondered if fitting it in the cold any air under the caps may have expanded affecting the one way valves, ie removed caps and pressurised but no joy. Any thoughts, or is this anoying noise normal. I know the obvious is to remove but that's a bind as as we're diesel our genys LPG so I've got the whole lot supported, which happens to be part of the extenda stays fitting destructions, ie a bit of a faff.