bathroom plubing and shower pumps

[thecaperino]

I am just about to buy a house which needs extensive work. I have installed a bathroom in my current property but want a shower in the new one. I have been doing some research on shower pumps and have had an idea to use the pump to feed the shower, bath and sink but i dont know whether it will work. The cold is tank fed and the only place the cold and hot come together is in the bathroom.

The plan is that i run the hot and cold supply into a cupboard behind the bathroom where i place a 2 bar pump, then i will feed the pumped supply back into the bathroom to the shower, bath and sink. will this work?

 

[Richard C]

More info needed; what type of hot water system do you have, gravity tank fed? combi boiler? What water storage capacity do you have?

 

[thecaperino]

standard central heating boiler, gravity fed tank and not sure of the hot water capacity but looks like a standard size hot water tank. sorry maybe not enough info.

 

[Richard C]

No such thing as a standard HW cylinder, what are the dimensions? Where is it located in relation to the CW storage tank? The pump should be mounted as close to the HW cylinder as possible, preferably at the bottom & fed by a proprietary anti-aeration flange. Shower pumps are designed to push water, they don’t suck very well at all & there is a limit to the length of pipe run from the water storage tanks of around 5m for 22mm feeds & just 3m for 15mm feeds, start to exceed that by any degree & performance will suffer drastically & the extra train can lead to early pump failure.

If you can put together more info about tank location/size & static head (vertical distance) to the CW storage tank I will be able to advise you a lot better.

 

[thecaperino]

i am going back to the property this weekend and will get those details, i assumed the HW cylinder was standard as the ones i have seen all look the same size. The HW cylinder is in a cupboard on the first floor and the CW tank is in the loft. I think the first place that the HW pipe and CW pipe converge is in the bathroom, the HW cylinder is about 3-4 meters away from the bathroom.

 

[Richard C]

Is your sink CW feed actually from the CW tank? It used to be done this way but is no longer permitted; sink taps should be on the mains CW supply as you will drink & clean your teeth with it! Personally I’d change it, you’d be amazed & disgusted at what is sometimes found lying at the bottom of old style CW storage tanks!

There are many things to consider when installing a pumped system; it depends on the age/design of your current tanks/pipe work system but if your revamping the bathroom & want a power shower that works well & doesn’t fry pumps every 18 months or so, you’re probably better budgeting to replace both tanks with suitably sized modern units (minimum size CW 250 litres; HW 160 litres). The best possible place for the pump is next to the bottom of HW cylinder & there will be a cold water feed from the tank in loft into the cylinder but you should not tap into this. Pumped systems of the size you’re proposing should always have a separate feeds for H & C water in 22mm; CW from the loft tank (opposite end to the mains infeed) & HW from the cylinder via a proprietary anti-aeration flange; preferably Essex side fitted flange. You can then install new direct piping to the bath & shower, preferably in 22mm; pipe work route & design is important to minimise restricting flow & avoid the need a more expensive negative head pump.

 

[thecaperino]

Ok so new plan (thanks to your input) i will be fitting the essex flange to the HW cylinder, i will be creating a new feed from the CW tank in the loft to go into the cupboard which houses the HW Cylinder. This is where i will place my pump to feed the shower and bath only, now the bathroom is about 3 meters away from the HW cylinder and i dont want to rip up floor boards. Do you think that the pump would work ok if i was to go from the pump back up to the loft then drop into the bathroom? This project is very time sensitive so i will need to use push fit or compression fittings which do you think are better?

 

[Richard C]

Do you think that the pump would work ok if i was to go from the pump back up to the loft then drop into the bathroom?

You can go up & over as long as it’s done correctly. The problem with up & over loops is if they are closer than around 600mm to the bottom of the CW storage tank you will start to get into a negative head situation with not enough static head (usually a minimum of 1 liter/min) to trigger the flow switches, you will then require a more expensive negative head pump. You must also vent the tops of the pipe loops or the pump will eventually air lock causing problems with the shower & even damaging the pump. Fit the new CW tank feed at the opposite end to the mains inlet.

This project is very time sensitive so i will need to use push fit or compression fittings which do you think are better?

I always run in 22mm soldered copper through to the mixer valve & I bend pipe work & use straight couplers rather than elbow fittings. Personally I would never use push fittings & only use compression where I have to so if I had to make a choice then compression; I would never, ever use plastic.

 

[lilplumber]

The plan is that i run the hot and cold supply into a cupboard behind the bathroom where i place a 2 bar pump

Just make sure your cupboard won't scrapped due to warmness and steam of Hot pipe.

 

[Richard C]

Just make sure your cupboard won't scrapped due to warmness and steam of Hot pipe.

Are you on something , it’s an airing cupboard not a steam room I don’t know what you do in the States (if that’s where you are) but what is proposed is standard practice here in the UK & not a lot different over there I would think.