Groaning water system - help please

[TonyV]

Our house is around 27 years old. It has warm air heating served by a gas fired 9-10 year old Johnson & Starley air heater with a dom. hot water heater on board too. We have not changed any plumbing for several years or changed anything about the way we use our systems. However about a year ago the house started to "groan" when we used the hot water, then after several months the groan went away. It has now returned with a vengeance. It starts a few moments after we use hot water. It is not related to any particular tap or appliance and it doesn't happen when running cold water. It is difficult to trace the source of the noise or indeed the cause. I've been told by a plumber to start by changing the main water tank float valve but surely if that is the source it would happen if we drew off cold water (apart from off riser fed taps). You may already have guessed that I am not a plumber! Any ideas gratefully received.
cheers

 

[justlead1]

Hi. I would take the advise of the plumber, for the sake of about a fiver you will may well get a result. Or try fitting a drogue to the ball valve arm. Just suspend a small plastic flower pot, using a piece of string / wire, so as it is just below the water line, the idea being and vibration present when filling the cistern will be dampened by the drogue. Good luck

 

[TonyV]

Hi Justlead1 and thanks for your advice. Would you advise that I change the complete unit or just the arm, float and seal?

 

[justlead1]

Hi The easy way if the type allows is to turn of supply, undo union nut on the ball valve on the inside of the cistern. Do the same nut on the new one and just replace this section. (be mindful that you do not replace without the flat red washer that fits between the union part of the valve) Good Luck

 

[stevetheplumber]

Our house is around 27 years old. It has warm air heating served by a gas fired 9-10 year old Johnson & Starley air heater with a dom. hot water heater on board too. We have not changed any plumbing for several years or changed anything about the way we use our systems. However about a year ago the house started to "groan" when we used the hot water, then after several months the groan went away. It has now returned with a vengeance. It starts a few moments after we use hot water. It is not related to any particular tap or appliance and it doesn't happen when running cold water. It is difficult to trace the source of the noise or indeed the cause. I've been told by a plumber to start by changing the main water tank float valve but surely if that is the source it would happen if we drew off cold water (apart from off riser fed taps). You may already have guessed that I am not a plumber! Any ideas gratefully received.
cheers

if this noise is only with hot water its unlikley to be the ball valve id would think its the water section on the circulator might just need a diaphram and some grease or a complete section
dont see many warm air heating systems in london this is one appliance i would recomend you have serviced by someone with experieence of them so many possible ways for them to cause problems

 

[TonyV]

Thanks for both replies. I always use a specialist to service the warm air heater and circulator. It used to be British Gas but the house nearly burnt down because they hadn't serviced the integrated circulator so they're off the list now!

 

[Beeline]

It could be the diverter valve, ok in winter when its used a lot but sticking in summer, Steve's right, you need a hot air registered engineer, try looking on the gas safe website.
Good luck.