Surrey Flange fitted, now have more air than before!

[briggster]

Hi All,

I'm in the process of fitting a wickes shower pump to run a new upstairs bathroom from an existing cylinder in an upstairs airing cupboard, fed by a tank in the loft above the cylinder.

I've installed a surrey flange (also from wickes) and have connected up the hot side of the circuit* but now when I run hot water from the bathroom taps I get more air out of them than before installing the flange.

I'm pretty sure I've connected it up right, the top connection goes up to the vent and the horizontal connection goes across then down to the pump on the floor of the airing cupboard.

Does anyone have any idea why the surrey flange would not be doing its job - my only thought is that somehow the vent isn't allowing the excess air to escape. The loft tank isn't directly over the cylinder so the vent pipe goes vertical from the tank for about 1.5 meters then has two 90deg bends before flipping over into the header tank.

Any and all suggestions are welcome as I'm now clueless

TIA

* (removing the old adapter from the top of the tank to make room for the new flange was a difficult birth so I have simply reconnected the hot side up to check for leaks before attempting the cold side

 

[seco services]

where is the hot supply for the rest of the house taken from or does all the hot supply to the house go through the pump ?

 

[briggster]

where is the hot supply for the rest of the house taken from or does all the hot supply to the house go through the pump ?

Currently it will all go through the pump, but we've having an extension fitted soon with new kitchen so the hot for that will come off of the top outlet of the surrey flange.

The shop assistant claimed that this pump (http://www.wickes.co.uk/invt/160404) can run the whole house if necessary so I didn't see the need to re-plumb the current kitchen which will be demolished in around 2 months.[/url]

 

[seco services]

if your going to run the whole house from the pump then no need for a surrey flange just place your pump in the existing dhw supply pipe.

 

[briggster]

From what I'd read, air in the supply to the pump would cause all kinds of problems so to pre-empt the problem I installed the surrey flange to try to purge the system of air as there was (and still is ) loads of air in the existing hotwater system.

 

[seco services]

if you had placed the pump as in pic with no surrey flange thats ok as the pump is below cylinder and the vent above. air will only go up not down.
they airlock when starved of water.

 

[seco services]

check your vent pipe is not drawing in air.
as the way you have installed it can cause one pipe circulation.
recommended measurement is 450mm min horizontal off the cylinder with a steady rise. then straight up.

 

[TicklyT]

Check there's no restriction in the cold feed to the bottom of the cylinder. If the cold feed can't keep up with the pump, it will draw air down the vent.

The usual suspects are a jammed gate valve or something wedged in the cold water storage tank outlet.

I once came across an old cylinder with so much limescale in the bottom that the cold feed would only run at a trickle.

 

[GasMan1965]

Can you take a pic of the cylinder and surrounding pipe work & connections ??

 

[briggster]

Thanks for the replys guys.

seco: I might reconfigure the vent when I next have a stab at it so that the horizontal section is at the top of the cylinder instead of the level with the loft tank. I guess that "horizontal with a steady rise" means something like 92.5 degrees?

Tickly: There isn't any restriction in the pipework to the bottom of the cylinder (all replaced) but the inside of it may well be full of cruddy limescale as its the existing tank.

I may be worrying about nothing, as I've yet to switch on the pump - I was just so surprised that the surrey valve made no difference to the amount of air in the water.

 

[seco services]

check the vent first when you run the pump.
put the vent into a glass of water and see if it draws the water in if so it's drawing air.