Installation of shower pump above hot water cylinder

[AlvoSlim]

I'm putting in a shower pump.

I've been advised that, although it is usual to fit a shower pump next to the hot water cylinder in the airing cupboad, the best bet in my house is to place it in the loft, next to where the h+c feeds drop down into the bathroom.

I've bought a pump and I'm all set to plumb it in and wire it up, but....
the manual advises that if I put the pump in above the hot water cylinder, it is "vulnerable to air-locks".

Should I have a rethink? What's the worst that can happen???

Help!!! Please!

 

[gas4you]

Shower pumps should push the water rather than pull.

Follow the MI's to the letter for installation.

 

[AlvoSlim]

the pump would be approx 1metre below the water level in the cold water tank in the loft.

Wouldn't that represent sufficient head to push water into the pump?

 

[hi-spec plumbing heating]

all you do is fit air bleed valves in the highest pipework.

 

[Eric'n'Ernie]

all you do is fit air bleed valves in the highest pipework.

Would this work?

 

[hi-spec plumbing heating]

as long as your pump is below your cws in loft and you have bleed the pipework at the highest point your only going to get air back in if the cws emptys etc.
many pumps are installed in the loft as shower pumps push water not pull

 

[ChrisR]

Take the HW supply from a flange on the cylinder, definitely NOT from the vent pipe!

 

[Eric'n'Ernie]

So if you plumb in a pump , below the level of the cold water tank in the loft so there's a head of water, and fit air bleed valves at the highest point in the pipework - then the jobs a good 'un?

 

[hi-spec plumbing heating]

never had one fail yet due to installation problem.
and don't use the cheap isolation valves with about 8mm bore get full bore valves.
and if you fit any non-return valves never fit before the pump always after the pump.

have you got a pump already?