UK Plumber Forum

[Dazzi13]

Hi all, I've become a little stuck and just need a few questions answered regarding an issue.

Basically a vented cylinder 900 x 400 and a 15 gallon header cold tank been installed I've begun the fill and it seems to stop filling about half way and stops and the header tank completely fills back up, it gushes down to begin with so nothing is blocked and nothing seems air locked as I did this a few times.

Is the size of the cylinder pushing back against the size of the 15 gallon tank, do I need to be getting a 25 or 40+gallon tank for this?

It's in a small annex type building so the tank isnt that much higher than the cylinder a few feet. What do you think? Any advice is greatly appreciated.

[Craig0787]

Size of the header tank wont make a difference. If your cylinder is only half filling up, its air locking. How do you know its only half full? Are you getting water out the got taps? Have you installed the vent pipe correctly?

[REDSAW]

Size of the header tank wont make a difference. If your cylinder is only half filling up, its air locking. How do you know its only half full? Are you getting water out the got taps? Have you installed the vent pipe correctly?

sounds like vent hight not correct or blocked to me!

Try filling with a hose down the vent pipe and watch it come up into the tank.

[Dazzi13]

Size of the header tank wont make a difference. If your cylinder is only half filling up, its air locking. How do you know its only half full? Are you getting water out the got taps? Have you installed the vent pipe correctly?

Hi mate, I disconnected the outlet for the hot water to see if this would allow the flow to come through and was able to shine my light inside and have a look and could see roughly where the water level was. Everything is installed and piped in correctly with the vent T'd off and up to the tank. I thought it was air but why would it get half full and then refuse to continue to fill, I also didn't think the size of the header tank mattered as it should still have a greater pressure to push through.

Do you think it is going to be an air lock? Even though I've drained it down a couple times and re done the process.

[REDSAW]

can you back fill it through a mixer tap?

[Dazzi13]

can you back fill it through a mixer tap?

I'll be there soon, so yeah going to give it a try back filling see if that sorts it.

[Craig0787]

So while the cylinder was filling, you've removed the hot draw off connection, looked inside, and the tank wouldn't fill any further than half way even while the header tank was full? The base of the header tank is definitely above the top of the cylinder? Perhaps a pic of the installation might help.

[TURNPIN]

Is your cold water storage cistern filling up quickly enough and does it supply both your hot and cold water?.......regards Turnpin