Unvented cylinder expansion tank problems?!

[stu550]

Hi all

Noticed the expansion tank was full of water/ very heavy and had lost pressure.

Isolated water, ran off water and starting pumping (with a high pressure manual bike pump).

Could not get any pressure into the expansion tank although air was going in...

When tap was opened and during pumping, dirty/ rusty water spat out during each 'pump' until it was just air being pumped through to the tap?! Couldn't get any pressure in the tank until I closed the tap - presume because that closed the system.

Does this mean my expansion tank diaphram is shot?! Assume so....

If it is, surely water would come out the valve or is there some sort of device to stop this?

On refilling, the tank refilled with water and the pressure went up on the bike pump.

thanks in advance. Appreciate these things shouldn't be meddled with - my plumber recommended recharging it in the first instance.

Appreciate thoughts! thanks.

 

[Dan Robinson]

It's guffed.

 

[stu550]

Cheers... that's all I needed to know!

Out of interest, why isn't water trying to come out the valve?!

 

[Dan Robinson]

Because where the bladder is sitting over the valve in ok, the point of failure is in a different part of the vessel.