pressurized hot water cylinder making a noise

[big craw]

hi

my hot waters cylinder (pressurized) has started making a noise when my washing machine is spinning,it sounds like the cylinder is contracting and then expanding.as if someone is pushing it in then letting go.I have reasonable plumbing knowledge but not on pressurized cylinders,,what i dont understand is that it only does it when machine is spinning!i would expect things to happen when machine filling for wash or spin.it is as if something drawing air out then letting it back in but dont know why it is happening.can anyone shed any light on it.please

 

[Puddle]

Well you have just described the exact sound the washing machine makes on spin ,when pump on pumping out the last of the water,sound travels and I think this is what is happening
omho

 

[big craw]

thanks for your prompt reply,next question why would it only start now cylinder is 3 years old (new House) never happened up until about a month ago.is it possible a check valve needing repace (faulty and letting air/water back through) or possible washing machine faulty.any ideas.cheers

 

[Dannypipe]

Is washing machine plumbed to just cold or hot too? When did you last re-establish the expansion air gap? Has any water dripped at the tundish?

 

[Puddle]

Try cleaning washing machine filter out,maybe putting strain on pump.as you say, no water is entering the machine when it is on spin only exiting,think machine not cylinder

now if you will excuss me just got a load of whites to do on 60' cold wash

imho

 

[Dannypipe]

Cold connection only on most modern W/M as they have an integral element.