Shower pump install?

[MattWeth]

I've been asked to fit a shower pump (open vented system). I've only done one before and it was a during a new hot and cold installation so easier to arrange the pipework).

The customer will be getting the pump himself (a Salamander, model to be decided) through a supplier which supplies his work (much better discount than I can get). It has to go in the loft next to the header tank. I could just about get it below the tank but it'll be marginal (the tank is on a low plinth in the loft so the top of the pump would just be below the base of the tank).

Would I be better of recommending that he gets a negative head pump to be on the safe side or would a gravity fed pump be ok?

Finally the hot feed from the cylinder...

The existing hot feed has a 90 immediately it exits the cylinder and runs horizontally to the side of the airing cupboard. Would it be ok to tee off this horizontal hot feed, taking it vertically down a foot or so and then bending 180 degrees to go back up into the loft, or should I do it by the book and replace the hot feed with an 'S-flange'?

cheers
Matt

 

[secret squirrel]

Have a look at the salamander web site its very useful, I think for the basic pump you need 600mm fall from the cwst to the pump.

You can get to attachments for this which turn it into a negative head pump, I forget what there called but if money is an issue its cheaper to do it that way than a specific neg head pump. This is from salamander themselves.

In relation to the drop from the hwc then can't see this being a problem, you can take the feed from lower down the hot water pipe as well this is in the manufacturers installation blurb

 

[mark_mc]

you will check with salamander i think even with the salamander negative head the pump needs to be certain distance below the cwst.

do it by the book install a surrey flange and take an independent supply of the cwst.
also with a salamander pump install a tmv mixer valve to protect the pump from the direct hot water from the cylinder.

 

[MattWeth]

Thanks fellers. I'll give salamander a ring.