Quick plumbing Q

[simpo two]

I need to run a hot feed from my bog-standard 1988 gravity-fed system to a shower pump in the roof.

I was going to tee it off from the short horizontal section of pipe immediately above the hot water cylinder, but as you can see there's a soldered connector in the middle that might be impossible to remove. I want to use a push-fit T due to confined space and not wanting to set the airing cupboard on fire...

Can I take the feed from the vertical section as it leaves the cylinder, or is that going to give me some problem I can't yet fathom?

Envisaged pipe run is shown in red, going back to the wall then up.

[pic]http://autograph.uk.com/Pix/pipes.jpg[/pic]

Ta :)

[nonegreen]

Normally you would locate the pump at the same level as the hot water tank and not in the loft. The pump will usually have a 22mm feed to cold input from the header tank and you would install an essex flange about 2/3 up the hot tank to feed the hot side of the pump. This ensures you have equal pressure feeds to the pump and therefore your output is also balanced. If you have to locate the pump in the loft you will have airlock problems. Hope that helps

[Ferg]

No, not under any circunstances like that. Drawing hot off the vent (i.e. the path air bubbles take from the cylinder) is bad news at the best of times, especially so if it goes to a pump, especially, especially so if it goes to 'up and over' pipe work. Essex or Surrey flange if you like or at the worst below that tee where the pipe goes up and down at the wall.
I wouldn't recommend a shower pump in the loft. Air locking is possible and is VERY bad news for pumps...also pumps must be ventilayed and, of course, in a roof space would need to be insulated.

Put the pump in the bottom of the airing cupboard, run a DEDICATED cold from the loft tank down and hot from that pipe below the vent tee, then run both pumped supplies back up into the loft to their destination. Put some MANUAL air vents in the roof and clear the air locks before energising the pump. Any air that DOES get into the pipework in time will easily be cleared by the pump.

IMPORTANT. Many pump manufacturers will walk away from warranty if you don't install to their instructions......

[simpo two]

Thanks very much Nonegreen and Ferg!

I should have mentioned that this is an Aqualisa Axis Digital shower www.aqualisashowers-direct.co.uk/ishop/1051/shopscr111.html and the installations state that the best place for the pump is... in the loft! It's not a whole house pump, it's a specific Aqualisa unit fed by 15mm hot and cold.

Ferg said:

Essex or Surrey flange if you like or at the worst below that tee where the pipe goes up and down at the wall.

Ah yes, I came across those when I was pondering a whole house pump and decided against it. I see what you mean about the air bubbles, it's just that the pipe against the wall is very difficult to get to/cut.

Is an Essex/Surrey flamge a straight swap for whatever's sticking into the HW cylinder at the moment? ie can a practical amateur do it?

Also, the pipes in my airing cupboard are for some reason painted silver. Do I need to remove this if using a push-fit T?

Thanks guys, I'm nearly there

[billynomates]

simpo two said:

Thanks very much Nonegreen and Ferg! I should have mentioned that this is an Aqualisa Axis Digital shower www.aqualisashowers-direct.co.uk/ishop/1051/shopscr111.html and the installations state that the best place for the pump is... in the loft! It's not a whole house pump, it's a specific Aqualisa unit fed by 15mm hot and cold. Ferg said: Essex or Surrey flange if you like or at the worst below that tee where the pipe goes up and down at the wall. Ah yes, I came across those when I was pondering a whole house pump and decided against it. I see what you mean about the air bubbles, it's just that the pipe against the wall is very difficult to get to/cut. Is an Essex/Surrey flamge a straight swap for whatever's sticking into the HW cylinder at the moment? ie can a practical amateur do it? Also, the pipes in my airing cupboard are for some reason painted silver. Do I need to remove this if using a push-fit T? Thanks guys, I'm nearly there

Jon

The flange jobbie screws into the top of the tank.

Just take it easy not to much heavy handed stuff.

Tis easy to fluck up the connections..ooopps new tank

[Ferg]

Aha! The Axis, nce bit of kit.

The Essex Flange requires cutting a hole in the cylinder to fit the flange...a Surrey flange replaces the fitting in the top and then takes the same fitting into it (if you see what I mean)...The Surrey is easier, just make sure your cylinder has an 1"BSP tapping on the top as this is the size of most common Surrey flanges.

I'm not going to let you off putting the tee where I said.....air bubbles will KILL the pump. I would clean the silver off before putting a fitting on.