Help fitting a pump to boost gravity fed hot water

[Tomo74]

Hi All
Can anybody help me i have a gravity fed hot water system with a cold mains supply with good pressure. the hot water is very low pressure. the en-suite is not to bad and can cope with it but would like more pressure to the rest of the house. I have a stuart Turner monsoon single pump i want to fit. but its a funny system (vented) i have done a diagram to show the system but don't want to put the pump in the wrong place because of the vent. and do i need any special valve/outlet on the top of the tank see pics??
Thanks

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• Tomo74
• 9 May 2011
• 1

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• Tomo74
• 9 May 2011
• 1

 

[bengasman]

Connect the inlet of the pump to the outlet of the cylinder with the connector indicated in the manual of the pump.
Didn't ST supply a diagram?

 

[Tomo74]

thats what i first thought, but would that start chucking water out of the vent above it back into the tank. the instuctions show the cylinder having two outlets one out of thr top for the vent and one on the side for the hot water with the pump on. my cylinder only has the one that supplys the vent and the hot water system as in the diagram.??

 

[bengasman]

No idea what you are on about.
Maybe you should consider getting a plumber to do it.

 

[digdilem]

If it's added before the T-piece, of course it will overflow. It'll keep pumping, never being able to achieve enough pressure to stop. If it's added below, it could easily suck air in from that vent.

But I'm confused. Why, in your diagram, is the hot water outlet side discharging into the central heating header tank?

I suspect you've made a mistake in your diagram. Either that or you've got a very strangely designed system.

Any vents in the hot water system would be manual or automatic air vents, never an open pipe since you'd never achieve pressure.

If your diagram is right, I suspect you would benefit from a bit of a pipework redesign before adding a pump. As if that overflows into the header, and the header is supplying the CH side which doesn't need any water, then the header will fill up and overflow.

 

[Tomo74]

The tank is the cold water header for the cylinder ( gravity fed). the central heating one is a small one next to it not shown on the pic. I think there is a special valve that can be fitted on the outlet on the cylinder so it gets no air to the pump. I think it's a surrey flange. Would this solve the problem?
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[moggridgeplumbing]

I'm confused, with what is quite a simple installation

Stuart & turner are very good pumps, and they always supply installation instructions.

Your diagram is wrong in many ways, and fitting a pump correctly, with equal and separate feeds are paramount to a good installation.

To be fair to you, it would pay you in the long run to get a plumber in to ensure correct installation.

 

[Tomo74]

wickes has a diagram of a system close to mine but my cold water is not gravity fed its straight off the mains and i want to improve the pressure of the hot water to the whole house not just the shower. the pump is off my dads system as he's gone to a combi .i have the instuctions but there no diagram of my setup only cylinders with a extra outlet on the side.

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• Tomo74
• 9 May 2011
• 1

 

[Tobler]

Hi,

I hope that you have found a sensible solution to your problem, as this post is 1 year old!

I can't believe how many total muppets have bothered to post a response to your request - have they never come across gravity fed systems (standard in the UK until the mid '90s)? It beggars belief!

There are 2 ways to put a pump in - I am assuming it is an automatic pressure-sensing pump with this, btw.

1. You fit it anywhere after the vent pipe to the tank, and you fit a check valve on the vent pipe to ensure that air is not sucked into the system. This valve should be a minimum of 1 metre up the vent riser, to allow for expansion/ contraction.
2. You fit the pump on the pipe dedicated to the shower that is exhibiting low pressure. You will still need a check valve in the same place.

If it is not an automatic pump (ie you switch it on manually) you will need a pressure relief valve somewhere in the system (between the pump outlet and the potentially closed taps, etc). I think that standard prvs are set at about 2.5-3 bar, but if you have plastic (pushfit) plumbing you may want a lower relief setting than this, to save the joints blowing.

I am not a trained plumber, but then it really isn't difficult! I've plumbed (and electriced) loads of houses and my work has been commended by many professionals, so I reckon I'm ok at it!

 

[misterdubya]

Hi,

I hope that you have found a sensible solution to your problem, as this post is 1 year old!

I can't believe how many total muppets have bothered to post a response to your request - have they never come across gravity fed systems (standard in the UK until the mid '90s)? It beggars belief!

There are 2 ways to put a pump in - I am assuming it is an automatic pressure-sensing pump with this, btw.

1. You fit it anywhere after the vent pipe to the tank, and you fit a check valve on the vent pipe to ensure that air is not sucked into the system. This valve should be a minimum of 1 metre up the vent riser, to allow for expansion/ contraction.
2. You fit the pump on the pipe dedicated to the shower that is exhibiting low pressure. You will still need a check valve in the same place.

If it is not an automatic pump (ie you switch it on manually) you will need a pressure relief valve somewhere in the system (between the pump outlet and the potentially closed taps, etc). I think that standard prvs are set at about 2.5-3 bar, but if you have plastic (pushfit) plumbing you may want a lower relief setting than this, to save the joints blowing.

I am not a trained plumber, but then it really isn't difficult! I've plumbed (and electriced) loads of houses and my work has been commended by many professionals, so I reckon I'm ok at it!

Im guessing its sorted out now - what a waste of your time writing that ramble.

 

[picasso]

Hi,



I can't believe how many total muppets have bothered to post a response to your request

1. You fit it anywhere after the vent pipe to the tank, and you fit a check valve on the vent pipe to ensure that air is not sucked into the system.

so I reckon I'm ok at it!

really! so you think its ok to fit a check valve on a vent pipe?, try reading the instructions as you dont seem to have any thing else to do except dragging up old posts and giving poor advice.

 

[slapper]

If it's added before the T-piece, of course it will overflow. It'll keep pumping, never being able to achieve enough pressure to stop. If it's added below, it could easily suck air in from that vent.

But I'm confused. Why, in your diagram, is the hot water outlet side discharging into the central heating header tank?

I suspect you've made a mistake in your diagram. Either that or you've got a very strangely designed system.

Any vents in the hot water system would be manual or automatic air vents, never an open pipe since you'd never achieve pressure.

If your diagram is right, I suspect you would benefit from a bit of a pipework redesign before adding a pump. As if that overflows into the header, and the header is supplying the CH side which doesn't need any water, then the header will fill up and overflow.

Methinks you need to go to spec savers,and a Plumbing course.

 

[Tobler]

Thanks for your rapid responses to my post,
I have a couple of questions to ask of you:

misterdubya - not a waste of time, being as the other 'solutions' were more than a waste of time as they were not solutions at all! 'Get a plumber in' is a bit crap in advice terms, I think anyone can work that one out... Your reply, however, is a complete waste of time for everyone! Get a life!

picasso - is it bad to fit a check valve on a vent pipe? I know it's not best practice but will it give a restriction to venting? I don't know, this is why I'm asking! As I stated, I am not a plumber, but then no-one else on this forum is, judging by their answers.

And I am 'dragging up an old post' because it is exactly the problem I have to overcome at the moment, so constructive advice is always useful to save bad things happening

 

[Dan Robinson]

You're an idiot.

Only an idiot will fit a check on an open vented cylinder vent!

 

[gaswizzard]

If you knew how to install the pump correctly you wouldn't require a check valve on the open vent , utter nonsense.

Can see only one 'muppet' posting on here,