Low water pressure from tank

seandeas

Hi,

I live in a small apartment and the storage tank is beneath ceiling level, over the hotpress. The water pressure in the bathroom is really low (always has been). The cistern takes ages to fill, the sink taps have better pressure as they're situated lower down and the bath taps have great pressure as they're at a lower level again. The washing machine is really slow because of the low pressure. There is a T40i pump attached to the mixer tap shower, which improves the pressure a bit but it's not great. (I don't want just to fit an electric pump shower feeding off the mains, I want to improve the gravity fed pressure overall)

Does anyone know if it's possible to get a pump attached to the cold water tank and immersion tank outlet pipes to improve the pressure and if so, roughly how much should it cost, supply and fit (Dublin CC) ?

Any advice appreciated

Joey the lips

No i dont think so. What your really looking to do is presurise your system. That will cost you around 5k but would be worth it. Sorry

cnocbui

Why 5K?

Surely he just needs a Stuart Turner pump connected to the cold outlet from the tank and the hot outlet from the cylinder?

That's basically what I did, now I have 3bar pressure throughout the house for less than €350 thanks to ebay and some DIY.

Pete67

It is possible to do what you are suggesting, a twin pump is used to boost both hot and cold supplies together - take a look at a sample pump from the Stuart Tuner site here.

You would need to get professional advice regarding the installation, electrical work will also be required, I would not expect much change from a grand to implement this. Probably worth it though.

Disadvantages are noise of pump running every time you use a tap, shower, washing machine, or flush a toilet. If you are on the ground floor and can bolt the pump to the concrete slab this will significantly reduce the noise levels. Worst case is bolted to a wooden floor which reverberates and transmits the pump noise throughout the building. I guess in an apartment you have concrete floors on each level anyway, so you should be OK.

You could also use a smaller version of this pump to just supply the shower mixer unit directly and leave the rest of the system on gravity feed to avoid unnecessary pump noise.

Joey the lips

cnocbui wrote: »

Why 5K?

Surely he just needs a Stuart Turner pump connected to the cold outlet from the tank and the hot outlet from the cylinder?

That's basically what I did, now I have 3bar pressure throughout the house for less than €350 thanks to ebay and some DIY.

Are you asking me to tell you why yours is wrong or why this cant be done here

cnocbui

Joey the lips wrote: »

Are you asking me to tell you why yours is wrong or why this cant be done here

Sure, I would be interested to know.

Joey the lips

cnocbui wrote: »

Why 5K?

Surely he just needs a Stuart Turner pump connected to the cold outlet from the tank and the hot outlet from the cylinder?

That's basically what I did, now I have 3bar pressure throughout the house for less than €350 thanks to ebay and some DIY.

Pete67 wrote: »

It is possible to do what you are suggesting, a twin pump is used to boost both hot and cold supplies together - take a look at a sample pump from the Stuart Tuner site here.

You would need to get professional advice regarding the installation, electrical work will also be required, I would not expect much change from a grand to implement this. Probably worth it though.

Disadvantages are noise of pump running every time you use a tap, shower, washing machine, or flush a toilet. If you are on the ground floor and can bolt the pump to the concrete slab this will significantly reduce the noise levels. Worst case is bolted to a wooden floor which reverberates and transmits the pump noise throughout the building. I guess in an apartment you have concrete floors on each level anyway, so you should be OK.

You could also use a smaller version of this pump to just supply the shower mixer unit directly and leave the rest of the system on gravity feed to avoid unnecessary pump noise.

Well thats interesting because now I have a problem. I dont think it can be done and pete does. I would go with pete on this one but here is my 2c worth.


I am guessing that the op has a standard cylinder in the house. A 3 bar pump drawing from a standard cylinder is two heavy. I go into flow rates but its not worth it. A min cyclinder size i would rec for a bar pump is a 42 or a 48" high. Additionally the only type of pump the monsoon agents in ireland rec for use in this application is a negative head pump. Washer Dryers and diswashers are the worst enemy of these. I know someone is going to say apartments but they only use 1.5bar and they have a lot of work to protect against this. Generally speaking.

The only thing that i think can be done is use the pump to draw on the shower only however the customer specifically says they dont want to use an electric pumped shower. Although this is not that it is the exact same it is the theory without the heating of the water.

Lastly, There is a T450I or simular pump fitted. I am guessing without asking that a plumber has already been there as these pumps are not ready available over the counter. Most people would buy an Argos single impeller as its cheaper. If the plumber fitted a T450I instead of a negative head pump it most likely means the pump cannot be fitted.

Although there is the chance of a dodgy plumber:eek:

Lastly I always accept that I can be wrong and if i am please accept my humble apologies. Perhaps pete can give us a little more insight, Educate me as well

cnocbui

I was not suggesting 3 bar for the OP, I was just saying that is what I fitted in my house where there are three toilets, two showers, a bath and four sinks. The washing machine and dishwasher have direct mains feeds.

I know my installation is not perfect as I did not fit an essex flange to the hot water cylinder. I just used the main take off to see if it would work without the flange and it did, so I have left it at that.

Obviously an apartment is going to have a smaller water cylinder so a lower capacity pump would be more appropriate. The pumps sold in Ireland are overpriced, like everything else. You can get a new 2 bar Stuart turner twin pump from the UK on eBay for about €200.

This is basically my setup except for the takeoff point from the cylinder. As this diagram is what is suggested by Stuart Turner, I can't see why it is thought to be un-doable.

Joey the lips

cnocbui wrote: »

I was not suggesting 3 bar for the OP, I was just saying that is what I fitted in my house where there are three toilets, two showers, a bath and four sinks. The washing machine and dishwasher have direct mains feeds.

I know my installation is not perfect as I did not fit an essex flange to the hot water cylinder. I just used the main take off to see if it would work without the flange and it did, so I have left it at that.

Obviously an apartment is going to have a smaller water cylinder so a lower capacity pump would be more appropriate. The pumps sold in Ireland are overpriced, like everything else. You can get a new 2 bar Stuart turner twin pump from the UK on eBay for about €200.

This is basically my setup except for the takeoff point from the cylinder. As this diagram is what is suggested by Stuart Turner, I can't see why it is thought to be un-doable.

an apartment and a house have simular parts but the feeds are generally negative head in an apartment and gravity in a house which in lay persons terms means there is no pressure without a pump. The pump is exactly like the one in the picture above. a stuart turner negative head pump in ireland is about 400-500 for 1.5 bar and 800 for a bar. Although they do come with a guarantee the irish agents will not honour it, so you will have to revert to the uk,

With due respect you told your story and advised how you used a 3 bar pump so anybody reading would assume a 3 bar pump is the way to go

cnocbui

My pump is exactly that model, 3 bar twin negative head. It cost me about €220 on eBay used. There was a slight weeping leak that was easily fixed and the pressure cylinder needed a few pumps of air but that is all.

Sorry, I should have said I thought 3 bar was overkill for an apartment.

The ones sold in Ireland are too expensive. On eBay - a Grundfos (Stuart Turner) twin impeller 2.0 bar negative head pump, final winning bid £330 or €366. Add about €30 for postage. A new 1.5 bar ST negative head pump on ebay - http://cgi.ebay.ie/Stuart-Turner-Negative-Head-Shower-Pump-1-5-bar-twin_W0QQitemZ170371100248QQcmdZViewItemQQptZUK_Home_Garden_Bathroom_Shower_Units_PP?hash=item27aae8ae58

€250.

IMO gravity fed water systems are unsuitable - period. All houses/apartments should have 2 Bar pressure at least and pumps - where necessary - should be standard practice, like lids on attic water tanks, not an expensive retro-fit.

Pete67

As you can see from the discussion while this can be done, it is not straightforward and hence I recommended seeking professional advice. A negative head pump is only required where there are outlets at the same level or higher than the cold water storage tank. Once there is a minimum gravity flow of 0.6 l/min from the highest outlet, (usually the shower head) then there is enough flow to prime the pump and enable the flow switch which starts the pump motor. In the OPs situation, it seems that this is the case, but this would need to be confirmed on site.

The size of the cold water storage tank and hot water cylinder also need to be taken into account, as does the ability of the existing pipework to supply the pump suction side. If there is insufficient flow available to the pump it will cavitate and distroy itself in fairly short order. The design of the installation also needs to ensure that the suction side of pump does not draw air down the vent from the hot water cylinder, so pipe sizing needs to be appropriate for the flowrate from the tank to the cylinder, and cylinder to the pump. A separate cold supply from the tank to the pump will also be required, and may need to be sized up from the existing line size.

It is also likely that the various taps etc throughout the apartment are intended to be used on a low pressure system, and may need to be changed. Also true for the ballcock in the toilet cisterns. The existing pumped shower would need to be replaced with a mixer tap, either standard or thermostatically controlled, with high pressure shower head. Subject to all of the above, yes it can be done.

Personally I would recommend clients install a 1.5 bar twin pump supplying just the shower via a new mixer and shower head to suit.

seandeas

Lads thanks for all the very helpful information - certainly it shows me will be possible to have a decent shower system for not an outrageous amount of money.

Cheers for that.