Power shower - up or down?

[Plumb_loco]

I am replacing a bathroom and intend to fit a power shower using a Showerforce 1.5bar Turbo 2 pump in the airing cupboard. I will be using a Surrey flange on a gravity system. I have around 1m between the base of the header tank and the shower-head. So far so good. However, the instructions for the pump say all pipework must be vertical to and from from the pump. That's OK for the feeds - but I want to go to the bathroom under the floorboards. I phoned Showerforce technical assistance and the chap said, no - the pipework must go up and over. He suggested there would be problems if I went down-under - but why not give it a try and see what happens - Hmmmmm !!!!!

A plumber has told me he always prefers to go down-under because there is more likelihood of airlocks going up-over - so he would fit vents. He reckons the Showerforce guy is misleading me. Other postings on the forum suggest down-under is preferred byyou guys too. Down-under would be a heck of a lot easier with my set-up. Any views or experiences would be gratefully received.

 

[chrishutt]

I can't see why there should be a problem going under the floor. One wonders why Showerforce have a problem with it. But if the pump fails you might find Showerforce renege on their guarantee if it's not installed according to their instructions.

 

[Plumb_loco]

Thanks Chris. I suspect the guy at Showerforce is following the manual but has no first hand experience. I am more inclined to go for experience. The manual says 'Where possible pipework should be vertical'. It has occurred to me that if the shower was downstairs it would be ridiculous to go up and over anyway.

 

[chrishutt]

But vertical doesn't only mean going up. It could equally mean going down. And ether way you have to have a horizontal run to get from pump to shower, so I think someone's got confused somewhere along the line.

 

[Plumb_loco]

Aha! Quite so. The diagrams in the manual all show the flexible hoses going upwards - but you're right, there seems to be no reason why they can't go vertically down. Thanks.

 

[bathjobby]

Aha! Quite so. The diagrams in the manual all show the flexible hoses going upwards - but you're right, there seems to be no reason why they can't go vertically down. Thanks.

Maybe its to keep the pump primed (pipes going down may let the water drain from the pump when not in use, depending on the rest of your setup) as the pump may not be designed to self prime every time its run. It may work like that but may wear itself out and you will have invalidated your guarantee. All maybe of course...

 

[Plumb_loco]

I did ask the Showerforce guy if the reason they had to go up initially to to ensure the sensors activated - he said no and then we got into the up and over discussion. He didn't mention anything about the need to prime the pump - but it makes sense. The manual does mention running the system under gravity the first time it is used before then running under power. Then I suppose all systems have to go through this process.

I asked if it would be OK to go up initially for a foot or so before then plunging into the depths but he seemed to think this was a bad idea - then said but why not try it and see. Hence I came away somewhat baffled. I'm wondering if it was the first time he'd been asked the question and so was thinking on the hoof.

Sometimes I wish manuals not only explained WHAT you need to do but also indicated WHY.

 

[bathjobby]

Maybe worth phoning again and hopefully getting a different person - try it and see (and if it doesn't work, re-do all your plumbing) is hardly satisfactory, ask for the manager.

 

[Plumb_loco]

Thanks for the suggestion. I couldn't raise anyone by phone so sent an email. Took a little while for the reply to arrive but this is what was said:

There is no reason why the SF Turbo 2 should not be installed
as you indicate. The only proviso I would add is that the flexible
connectors should be as straight as possible, and should not be bent
through more than 90° over the whole length of the hose. The fact that the pipework will run under the floor is not a problem, as long as the cold
water storage tank is high enough to provide sufficient gravity cold water
pressure to operate the flow switches, and clear any air locks.

Thanks to all for your suggestions and input - I am now reassured that:

a) it will work
b) I'll not void my warranty