Air in shower pump, how likely is this?

[1justin]

Hi. I'm basically an electrician, but we do need to do some of everything in this world.

I'll begin by saying I've installed several shower pumps before, always successfully, and always using "good practice" with a air-free flange and separate shower pump feed from the tank. No problems yet..

A new customer has asked me to install a shower pump. Open vented system. There are only single feeds to the bathroom (bath sink, shower) in unjointed plastic, 15mm, from the tank and the header tank. Tank is probably 6M horizontally from the shower. The vertical head from the cold tank water level to the shower head will be about 1.5M.
The tank 22mm exit appears to be an ordinary central one without Surrey flange.
Bathroom has sink taps take-off BEFORE the proposed pump location, (bath taps would be after).

I've advised the customer about my doubts regarding air ingress (either direct off the tank, or from someone opening the sink taps). I have advised a low power max 1.5 bar pump to slow things down a bit, and reduce the possibility of a problem.

In terms of actually experiencing air-in pump type problems, I can't evaluate the risk since I feel I've always done it the proper way myself, and haven't encountered this one. Customer doesn't want to install any new feed pipes.

Anecdotally, what's the likelyhood of this becoming a (not unforseen) problem if I go ahead with fitting the pump?

 

[Jones82]

I'd say highly likely there will be a problem, not only by the ingress of air but also by the pump not having its own independent feed, meaning it could be starved of water.

Your best course of action is to consult the manufacturers instructions or call them directly.

When it comes down to it, if you install it "incorrectly" it won't be covered by a manufactures guarantee so you'll likely be the one going back to it, free of charge... I'd stay well clear of it if I were you.