What size pump for shower and later the loft conversion

Sorry if this has been covered but I couldn't find a decent discussion on pump sizes that seemed to cover my scenario. Here goes...

I would like to fit a pump to use with a shower that is about 6m away. In the future I would like to convert the loft and have a bathroom up there with another bath/shower.

  1. What size pump should I use? - for one shower now. - and for an additional bathroom in the future.

  1. Are there any important installation considerations that I may have overlooked or am likely to overlook?

I'm happy for anyone to just refer me to another site where I can find the information, I didn't have much luck.

I have made the following assumptions

------------------------------------------------------- I will need a negative head pump (e.g. Stuart Turner Monsoon Twin Negative).

I may need to upgrade / elevate / resite the current cold water tank in the future, to cope with the extra flow.

I should site the pump on the floor next to the HW tank. I should run a 22mm hot pipe into the loft and then to the site of current shower. I should run a 22mm cold pipe from the CW tank to the site of current shower. I should cut notches in the joists and lag the these 22mm pipes.

Thank in advance

Charlie

Reply to
Charlie
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The presumption is that it is a two-storey house with the hot tank on the upper floor?

Why? (this shows my ignorance). Is the pump sucking the water up or just pushing the water up?

Again, you don't specify how big the existing tank is. Separate cold feed to the (presumed) twin impeller pump with the cold draw off on the cold tank higher than the cold feed to the hot tank. All for the rare case that when your mains water fails the shower occupier gets a cold shower (as the tank runs dry) and not scalded. Take-off from the cold tank at the other end from the feed to the tank to prevent areas of "stagnant" water too (in case this is not present already). Pipework from cold tank to shower pump to be "continuously descending" so that any air in the pipe runs up into the cold tank.

Just installed a Stuart Turner 3-bar pump for one new shower (don't plan to use the pump for any other showers at the moment, but things can change). I've sat the pump in a plastic tray as a future contingency for the inevitable spills in the future.

Draw off from my hot tank via home-made Essex flange (right county?) as discussed here some weeks ago.

Aye, off the pump. The book says to use 22mm for all the flow AND its a good idea to bend the pipes in wide arcs instead of 90 degree elbows. I bought the pipe bender tool from Toolstation (twenty quid) and although bending 22mm requires some strength and ingenuity I wouldn't go back to using 45 degree connectors and the like.

Are you pumping the hot only? I bought a twin impeller pump and let it handle both the hot and the cold.

Notching joists is never my favourite installation choice: can you not run the pipes in some way as to avoid notching?

I am at the stage of being able to test the pump in an ensuite room devoid of tiles (one large bucket on the floor to catch the water). First impression is that the pump is good but it does generate some noise. All to be expected though (this is my first time in using a pump).

When I run 22mm pipe I buy "saddle" plastic pipe clips (40mm or even

50mm) that are normally used for waste pipes. Thus I secure the 22mm covered in 9mm insulation as a whole instead of insulating up to the clip then after it (and covering the clip in some kind of bandage wrap stuff).

Hope this is of some help

Mungo

Reply to
Mungo

If your mains is good enough, then consider installing a mains pressure hot water system (i.e. unvented cylinder or heatbank). They are ideal for loft conversions, as you don't need a noisy pump and you don't have all the negative head problems associated with having the shower head above the level of the cold tank. You also save the space taken by the cold tank, which can cramp your style when designing the loft layout. By the time you've added up a decent pump and all the hassle of moving/replacing the cold tank, you might not find it that more expensive.

Christian.

Reply to
Christian McArdle

Yes that's right.

When the loft is converted the loft bathroom will have a shower head ABOVE the height of the CW tank. Any taps will have a very small head.

OK thanks, that makes sense.

Homemade? I think I'll just buy one!

OK pipe bender it is.

Sorry my fault, I meant run the 22mm cold pipe to the pump and then up and over to the shower.

This was my concern, maybe it's just easier to run the pipes over the joist and then rejig once the loft is actually converted and it's clear where thay can be hidden.

Neat idea!

Reply to
Charlie

For all it was, I bought a one-inch to 22mm pipe brass fitting that screwed in to an existing (but blanked) socket on my hot tank. I got my old man to use his lathe to remove the 22mm pipe stop inside the fitting, then just bent a piece of 22mm copper pipe to the right angle and laced it through this fitting into the tank. The end result is that this will draw off water from inside the tank but quite high up. Seems to work a treat so far, but haven't used it in earnest yet.

Mungo

Reply to
Mungo

Meant to add: when working on a hot cylinder it is important to ensure that it is quite full with water so that the pressure of your spanner on any fitting doesn't "wrinkle" the thin copper of the tank! Yes, I didn't appreciate this. No, I haven't ever wrinkled a tank. Yes, I can see how it could happen!

Usually when you are attempting to free off a fitting that has been there for donkeys years.

Mungo

Reply to
Mungo

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