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Vibration in back boiler pipes.

  • 26-02-2010 11:54pm
    Closed Accounts Posts: 1

    Hi all,

    I have a triple coil HWC (oil boiler, back boiler and solar). As well as providing hot water the back boiler heats rads downstairs, thermostat set at 60 degrees. All 3 heat sourses worked very well but I was loosing heat generated by solar to back boiler. Got plumber to fit non return valve which has solved the problem. The valve was fitted on the hot water feed from back boiler right next to HWC. My new problem now is ever since the valve was fitted, when the water from back boiler reaches 60 degrees the pump is triggered, all as it should be. However, for the first 5-10 seconds following the pump switching on there is a vibration coming from the ceiling where the hot water flow is located. I have read on previous threads that the non return valves can vibrate but this is far away from the valve, closer to the fire than the HWC and appears to be located at a 90 degree bend in the pipe. The noise sounds like the pipe is tapping against the ceiling but the ceiling and pipes are insulated. I have planned to lift the carpet in upstairs bedroom and lift floor to investigate. Is it worth my while????
    Many thanks to all.


  • Closed Accounts Posts: 672 ✭✭✭items

    Your right with NRV some do create a noise, any I've heard gave more a ticking sound than knocking or vibration. Their is two type of NRV, spring or flap, spring loaded should be used in houses etc as they are silent, flap types more used in boiler / plant rooms.

    You might have spring loaded NRV already fitted.

    The sound you hear could be sound given from pipes expanding as they heat up, pipes and fittings might be running tight against ceiling joists rubbing off giving that knocking sound as they start to heat up. I doubt every single inch of pipe is insulated, their could be no insulation on fittings etc so best take up carpet and floor to see where problem is, that knocking sound is probably doing head in.

    Better still, unless knocking pipes came with price, call plumber back.