Unvented hot water tank disconnects the internet - yes really!

Discussion in 'Plumbers' Talk' started by Funkgroover, Nov 5, 2020.

  1. Funkgroover

    Funkgroover New Member

    I have Joule unvented hot water tank. It's about 5 years old and we've never had a problem with hot water or pressure, but...

    A couple of times a day, always when the central heating is on we hear a hissing sound. This lasts 3 - 5 seconds. I believe it is a release of pressure even though the water temperature is only set at 35 degrees.

    When this happens, we lose the internet for 1 - 2 minutes. The router stays switched on so it's not the power going off and it happens every time.

    I'd like to stop the hissing if possible but would really like to stop losing the broadband connection if it does.

    Thanks to anyone that can help.
  2. Teki

    Teki Screwfix Select

    Is there any sign of water in the tundish after you hear a hissing sound? You need to have this looked at by a plumber/GSR who has a G3 certificate to work on unvented cylinders.

    How are you connected to the Internet, wired connection or WiFi? If WiFi, check if you also lose the connection with an Ethernet cable connected.
  3. Funkgroover

    Funkgroover New Member

    Assuming that I have located the tundish then there was no sign of water an hour after the last hiss and it feels dry to the touch inside.

    As for the internet, both the Wi-Fi and ethernet connections are affected.

    2020-11-05 19.09.46.jpg
  4. Teki

    Teki Screwfix Select

  5. Wayners

    Wayners Screwfix Select

    You have a modern WiFi connected boiler? Maybe it's sending signal that's Knocking off your WiFi. Very bizarre problem you have there...

    Also try WiFi monitoring app as should show dropout times and might help if it's a regular thing when you are unaware

    I'd also turn boiler off at power for a few hours at a time and see what happens to WiFi.
  6. Funkgroover

    Funkgroover New Member

  7. Funkgroover

    Funkgroover New Member

    The boiler is about four years old but it's a normal boiler, not wi-fi connected. Even the thermostat is a traditional one and not wi-fi connected.

    I have a wi-fi alarm - also known as a pre-teen who goes crazy when the wi-fi drops! I know we lose internet occasionally but I also know for sure that it happens very shortly after each pressure release.
  8. Teki

    Teki Screwfix Select

    If one or the other are periodically venting, then you have a lot of air in the system. Either a purge hasn't been carried out at the last service, your inhibitor is running low or you have air getting into the system

    How often do you have to top up the system?

    Where is the router situated in relation to any central heating controls? Can you temporarily move it to another socket on a different floor (if upstairs then downstairs or vice-versa)?
  9. Funkgroover

    Funkgroover New Member

    So far we have not had the system serviced. I didn't know that was a requirement. Is a purge something that I can do or is it for someone that knows what they are doing?

    I have never topped up the system.

    The router is on the same floor but two rooms over. Moving it is very difficult as the are many connections plugged in and I need to wait for an indeterminate amount of time until the system vents again to see if it has an impact.
  10. Teki

    Teki Screwfix Select

    Are you sure you've never topped up the system ever in 5 years using the filling loop? What is the current pressure showing on the boiler gauge?

    If it is venting that often, I would suggest you have the system serviced. The system water should be drained and filled with inhibitor added.

    If the inhibitor is too dilute, your radiators will start to corrode.

    Is there a system filter fitted and has it ever been emptied? It might look something like this:

  11. Funkgroover

    Funkgroover New Member

    Hi. I think we may be at cross purposes. This doesn't as far as I'm aware deal with the heating at all, just the hot water. There is no pressure gauge and no system filler or anything that looks like I could top it up. I can certainly say that I have never topped it up in the five years I have had it.
  12. Teki

    Teki Screwfix Select

    The hot flow water from the boiler heats both the radiators and the unvented tank depending on how your programmer is set. The two vents are probably for each circuit.

    Are you able to post photos of the setup around your tank? What is the make and model of the boiler? The gauge may be digital on the screen on your boiler.

    To try and solve your Internet problem, try moving the router to another floor as I mentioned above.
  13. Confusedofstalbans

    Confusedofstalbans New Member

    Do you have a wired phone on the same line as the bband? If so, can you hear noise/ interference when the boiler vents? Not impossible a bimetallic thermostat in the boiler is 'buzzing' and inducing interference on the phone line. An old radio switched to long wave AM might pick up the interference as well?
  14. Teki

    Teki Screwfix Select

    It seems like it could be interference from one of your central heating devices switching as Confusedofstalbans is also suggesting. So physically moving the router to another level may help to identify the problem.

    How many telephone sockets are there in the house?
  15. Tuxmark2

    Tuxmark2 Active Member

    A AM radio will pick up that type of interference easily enough but I think a clue will be in the modem / router logs that may show disconnects each time interference knocks the connection out, the OP should look at the connection uptime in relation to the boiler playing up if the router doesn't have full logging, if it is the boiler then there will be a correlation.

    However, its not unknown for a router to develop a fault where normal electrical noise will cause it to disconnect from the internet, drop Wi-Fi, loose connectivity to USB dongles or just plain old reboot itself.
  16. Funkgroover

    Funkgroover New Member

    Just the one. S I can move the router on a long extension but the socket would be the same.
  17. Funkgroover

    Funkgroover New Member

    Water system top and bottom

    Attached Files:

  18. Funkgroover

    Funkgroover New Member

    The boiler display shows the temperature but not the water pressure.

    Attached Files:

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