Options for a better shower

[Colin Harper]

Our house was a new build 10 years ago and the en suite shower was never very good. Now it's really not very good.

We have a system boiler, hot water storage tank upstairs, the builder installed en suite shower is gravity fed mixer, one temperature valve and one flow valve. No idea on manufacturer.

What are the options for getting a shower with more /oomph/ ?

I figure that there are three options.

1) Work out what's wrong with the gravity fed mixer system and/or install a better gravity fed mixer (are these all created equal - can you get a /better/ one?)

2) Replace with Electric shower

3) Replace existing mixer with new + install Shower Pump

Now in the airing cupboard where the hot water cylinder is, I'm fairly sure the hot shower feed comes from there on a separate water pipe. The pump for the central heating is in there too, so there's probably a decent electrical supply.

Are any of these options better/worse than others and how much work could I do myself? I'm pretty sure the electrical work for an electric shower would be difficult. There's no spare MCB in the CU to run a 30A feed from and I guess as it involves a shower, I couldn't do it myself anyway.

Thanks for opinions

Col

[Tim W]

Colin Harper wibbled on Monday 21 December 2009 14:45

If you have plentiful HW that would be my option. Much better flow than with a weedy electric shower.

May not have permanent live though. Might also overload the circuit even if you can hack a permanet live and neutral out of the wiring (some of the shower pumps are quite heavy duty). Wouldn't recommend that approach.

But, how hard is it to get at the wiring for a local socket ring circuit, say from the adjacent room, to take a fused spur off?

or 40A or 45A depending on shower power(!)

You can. But technically you should do a Building Control job on it.

Technically, messing with a fused spur into the air cupboard (assuming that is in a bathroom) would require notification too, but less likelihood of anyone noticing.

You really would want an RCD on the supply to the shower pump too - are your socket circuits RCD protected right now?

[Usenet Nutter]

I get fed up with folk in here condemning electric showers just ( presumably) because of their own experience with them .I have had electric showers in my flat since virtually the day I moved in and get an excellent shower with them because of the amount of water + pressure available to it which comes form a rising main supplying 4 flats in this block and I am 2 floors up as well. As an example when you turn the water on full in the kitchen or the bathroom w/h basin it al,most bounces up and hits you in the face .

[Tim W]

Usenet Nutter wibbled on Monday 21 December 2009 15:24

I;m sure a 10.8kW shower at mains pressure is relatively excellent.

I've only had experience of the lower power units (because holiday cottage people are cheap sods sometimes).

But it makes a lot less sense to fit an electric shower requiring chunky cable back to the CU if a pump at 600-800W can make more use of plentiful, cheaper and existing HW.

[Roger Mills]

Oh, there's no problem with getting a veritable torrent out of a *cold* shower - it's only when you (unreasonably!) want it hot that the flow is limited by the rate at which you can heat it. Even with 10kW, the flow is less than wonderful when the incoming water is barely above freezing - like it is at present.

[Usenet Nutter]

Oh right ..I must have missed the occasion when you stayed at my place ..remind me again .

Total Bollocks

[Roger Mills]

Go for a shower pump every time. A shower which uses stored hot water is far superior to any electric shower.

Is there any need to replace the mixer - can't you just boost the hot and cold pressure to it with a pump? [I assume that the cold feed comes from the header tank so that H&C are at the same pressure?] You just need to find the most suitable place where you can intercept the feeds to the shower and insert a dual pump - something like

- triggered by a flow switch. Find a convenient place to take a spur off a ring main to power the pump - preferably via an RCD.

If you really can't find a suitable location to install a separate pump, simply replace your existing mixer with something like this:

on your capability, there's no reason not to do *all* of that yourself - I certainly would!

[Roger Mills]

Hello Mr Bollocks,

I don't recall staying at your place, but I see no reason to suppose that the laws of physics would be any different there from anywhere else!

[John Rumm]

What you are basically saying is that you are happy with your shower. No one is disagreeing.

However if you are used to having a shower that can lob at least 10 lpm at you, then you *will* find an electric one disappointing. That's just basic physics: 10500*60/4200/35= 4.3 lpm.

Now 4.3 lpm is better than nothing - but it won't exactly wash you away. In the summer with ground water at say 15 degrees, when you only need lift the temperature by 25, then the story is much better at 6 lpm. That's still a bit down on the bottom end of expectations from a mixer shower.

Personally I would rate 10+ lpm as good, and 7 lpm as ok but nothing special.

[Bob Minchin]

According to the back of my envelope, a 10kW shower should heat 3-4 litres of water per minute from near zero to 40C. Not exactly a raging torrent power shower but enough for the purpose I would have thought.

Bob

[Usenet Nutter]

That's fair enough ..Each to his own but I just can't see the fascination of wanting/needing all that water coming out a shower when a lot of it will miss whoever is in the shower anyway and ,of course,i will all end up down the same plughole . And nobody has mentioned the cost of heating all this extra water incl those who have water meters .

[Invisible Man]

If your existing hot water supply is adequate go for the pump. No need for anything more than a fused spur off an existing ring.

Shower head and the bore of any flexible pipe will affect performance. Shower heads make a lot of difference and in hard water areas without a water softener they do get affected by scale.

Keep the run of plumbing as straight as possible.

[Tim W]

Bob Minchin wibbled on Monday 21 December 2009 17:41

Your figures are right Bob. Did the same calc for my 9.5kW water heater. It is flow limited to 4l/min and the water coming out is near enough the right temp for a bath or shower.

It is a fairly feeble flow though. Doesn't matter with the bath (I can plan ahead to fill that). It would suffice for a shower, but it would not exactly be an amazing experience.

[Roger Mills]

But don't forget that on-peak electricity costs three times as much as gas, so if you use stored water which has been heated by gas, you can use getting on for 3 times as much without it costing any more to heat!

[Chris Bartram]

Same here, and I'd imagine a lot of people's experience is of low-power ones. They're pretty dreadful.

The problem of course is that to install a good electric shower, you need to get a pretty damned hefty cable to it from a dedicated feed.

[John Rumm]

One can improve matters with many showers by careful choice of shower head etc. That can make lower flow rates feel better than they otherwise might. However once you get used to a reasonably forceful application of water, you do tend to miss it.

Cost is usually less of an issue since the stored hot water will often be heated by something cheaper than electricity. There will be a difference in water use, but that probably does not translate to that much extra cost.

[Rob]

About 8 lpm from my gas combi, and that's no torrent in use.

[Vortex4]

4) Replace HW tank with a thermal store like XCEL 2009 from and get some (thermal) solar panels.

• Mains pressure DHW * Much more efficient boiler usage. ZERO gas bill for half the year.

[Doctor Drivel]

The mixer is most prob' a low pressure model and needs replacing.

You could put in a £250 Stuart Turner power shower pump and associated piping.

Or, a Grundfos Home Booster Pump. Before the mixer fit a pressure equalisation valve - about £30. Some mixers have them, integrated. Have the hot water run through one side and the cold water mains through the other. Between the cylinder and the equalisation have fit the Home Booster pump -about £100 or so. Check specs before fitting. Details of pump on the web.

The equalisation valve ensures one side is the same pressure as the lowest. So if the cold mains is 2.5 bar, and the Home Booster gives approx 0.8 to 1 bar the cold will be at the same pressure as Home Booster pump, giving equal pressure at the mixer. Fit pump as close to mixer as possible.

[blod]

Another possibility is to get a Trevi Boost shower. We have had one upstairs, in the same room as the hot water cylinder, for 4 years, and it works very well. The hot water pressure is much better than it was in our conventional gravity fed shower downstairs. There's no electric connection and no pump noise. If I remember right, it cost the about same as a good conventional shower that works with hot and cold supply. How it does this is something to do with the venturi principle, which I don't understand at all. Worth looking into.