Strange hot water flow issue

[terryplumb]

No idea what size it is ,never seen one. It's built into the cylinder during manufacture. You may wish to contact the manufacturer ,I believe their cylinders are guaranteed for around 15/ 20 years. But they will expect the cylinder to have been serviced annually,and may not admit that the plastic thing they fit inside the cylinder is duff !! I can't remember what they call it ,maybe a spreader.

 

[Bretty1984]

Yeah it hasn't been serviced. I've only ever had my boiler serviced. I was speaking to my neighbours today and two of them have not had theirs serviced and did not know they needed too. I was gonna give them a call anyhow and find out what they say

 

[Agile]

Some unventeds have a large plastic disc which floats on the water to create an air gap to absorb expansion.

But I have never heard of one breaking up and I did not think that your make used them and has a separate white expansion vessel.

 

[Bretty1984]

Some unventeds have a large plastic disc which floats on the water to create an air gap to absorb expansion.

But I have never heard of one breaking up and I did not think that your make used them and has a separate white expansion vessel.

That's right, I do have a separate white expansion vessel. I've removed the aerators from the taps for the time being to allow the grit to come out. Some of it is very powdery and some of it can be snapped. I'm not sure if it is plastic or whether it's a build up of something