Poor shower

[Hugo Nebula]

I've just moved into a new house, and I have a problem with the shower. It's a mixer shower in a cubicle gravity fed from the hot water cylinder on the same floor, and the cold tank in the loft just above. It produces not so much a shower as a dribble.

My options as I see it are:

1. Replace the mixer valve with a pumped shower. This would appear to be the easiest option, as I would have thought it just requires an electrical supply, the water inlets being already in place.

1. Install a pump. This appears as though it will have to go in the airing cupboard, and I'm assuming will therefore need a new hot and cold feed to the shower valve, as well as the wiring.

-Two questions here: a) can a pump be fitted in the loft above the height of the shower head and the hot water tank? Most typical installations show them being fitted on a level with the hot water cylinder, but if it were fitted in the loft, I could presumably place it in the line of the hot & cold feeds, thereby reducing the amount of plumbing needed; and b) could I take a spur or loop from the immersion heater?

1. Replace the existing vented cylinder with a Megaflo. A bit of a nuclear option, I would have thought, but there was one in the rented flat I've just moved from, and the shower there was almost too powerful. There appears to be good mains pressure here. Is it feasible to simply swap one cylinder for another and bypass the cold water tank, or is there more to it than that?

Any thoughts on the pros and cons of these options are welcome.

[The3rd Earl Of Derby]

I can't understand why people go to the extent of installing a shower cubical and then use a gravity fed shower mixer?

Put a proper shower unit in.

-- Sir Benjamin Middlethwaite

[Paul Andrews]

Perhaps because for a lot of people it will work. Our neighbour has one on the ground floor, cold water tank in the loft - perfectly acceptable flow. Naturally upstairs would be a no-no (as in the OPs case).

[Doctor Drivel]

I assume you mean a pump inside the casing. You may need to fit a Surrey flange.

You may need a Surrey flange, and some pipework alterations here and there. Pumps usually only give 1 bar pressure, which is not that much; OK though as it is better than running around a shower to get wet.. Pumps which deliver

3 bar are around £500. Then you may need to change the cartridge in the shower to a high pressure cartridge. What make and type of shower mixer is it?

Avoid a unvented cylinder (Megaflow). You need an annual service by a BBA plumber. If no service an insurance company will not pay out if any damage. They can explode.

You have a number of options to get a decent shower.

1. Install a condensing combi and have only the shower off the water section. The CH side operates as a normal system boiler heating the cylinder. You will then have a 3 barish shower (£500 plus using pump) and a new high efficient boiler too. A combi can be had for the price of the high pressure 3 bar pump. Well worth considering as it will save you money in gas bills.
2. Install a shower coil cylinder. This will replace the existing cylinder and retains the tank. A straight swap. It has a coil inside for running the shower from the mains. It instantly heats the incoming mains water for the shower. The heat inside the cylinder transfers its heat to the shower coil. Install a DHW only heat bank or thermal store. These gives high pressure mains water at "all" taps and can eliminate the cold water tank. It can also go in the loft liberating needed space in the house. At low pressure and no annual service charge.
3. Install a venturi shower mixer that runs from low pressure hot and high pressure cold. It must be with in the makers pressure guide for hot and cold supplies.

[Sadly]

Like this one perhaps (1.3 bar for =A3139.99):

this one (1.5 bar for =A399.99): this (2.0 bar for =A3169.99): this (2.25 bar for =A3229.99): Pumps which deliver 3 bar are around =A3500.

Like this (3.3 bar for =A3279.99):

this (3.3 bar for =A3399.99):

[Dave Plowman (News)]

It can work perfectly well with a head of about 3 metres if you use a suitable shower fed via 22mm pipe and take care with the pipe runs.

[Dave Plowman (News)]

Confusing flow with pressure again, pet?

If someone upended a bucket of water over you would that be high pressure?

The sort of shower where you have to 'run around to get wet' is invariably high pressure - an electric one fed from mains water.

[Doctor Drivel]

..this senile man he calls me pet ..of inverted gender he must be set ..he gives us info we don't need to know ..down our throats he rams it so

..instictively you will spy ..in newsgroups with DIY ..attempting wisdom this fool will try

..the info's so poor tis clearly true ..so how does this garbage affect you?

..well take no heed of babble and drool ..as this one is a confirmed fool

..he marches around in CAT boots of yellow ..this strange brain damaged sort of fellow

..misadvice he has lots to say ..so don't give this yellow booted half-wit the time of day

[Doctor Drivel]

Sure it can

** snip senility **

[Doctor Drivel]

Like this one perhaps (1.3 bar for £139.99):

this one (1.5 bar for £99.99): this (2.0 bar for £169.99): this (2.25 bar for £229.99): Pumps which deliver 3 bar are around £500.

Like this (3.3 bar for £279.99):

this (3.3 bar for £399.99): sadly will scream the house down and and will not last too long. There you go. Give them all a wide berth.

[Ed Sirett]

Firstly there may simply be something wrong with the existing arrangements which may well work well enough for you when corrected.

With a thermostatic mixer a failure of either supply will result in next to nothing. The head may be totally clogged with lime or other crap. Sometimes people put on a fancy head which requires a better supply, simply going back to a more modest shower head can make things much better.

1 & 2 are essentially the same option although neither will work (and may not be needed) if there is an underlying problem with the supplies. Most pumps need to be installed low to keep the running inlet pressure up when in operation. A low inlet pressure encourages cavitation which can damage a pump. 3 Is the best practice and will work well for a shower even if the main is only a 20mm MDPE, 15mm or "7 pound" supply if the pressure is good. It won't come cheap and may not give a much better bath fill rate unless the main is upped to 25mm MDPE.

PS Do you get free building notices as part of the job ?!? Apparently holding a G3 ticket is not enough to be able to self-certify the notification for an unvented through CORGI you also need IoP membership.

[Hugo Nebula]

On Sat, 10 Dec 2005 14:20:48 -0000, a particular chimpanzee named "Doctor Drivel" randomly hit the keyboard and produced:

Looks similar to

which will operate to 10 bar.

[Doctor Drivel]

It may be a high pressure mixer on allow pressure system. Very common.

[Andy Hall]

Bollocks.

Possibly if you buy a crappy one from Lidl.

If you buy a decent product such as Stuart Turner it will last 10-20 years and be quiet as well.

[Doctor Drivel]

But Matt! All those Screwfix things are nasty and cheap. A 3 bar ST is £500. May as well but a proper cheap to run condensing combi and have 4 bar and no noise. Matt at times you are dumb.

[Andy Hall]

What are you going to do if the mains pressure is 1-1.5 bar and the flow rate is 12lpm with no economic possibility of making a change?

[Doctor Drivel]

He has excellent flow and pressure, so not a problem.

[Hugo Nebula]

On Sat, 10 Dec 2005 19:01:08 +0000, a particular chimpanzee named Ed Sirett randomly hit the keyboard and produced:

Don't think the head is clogged; I replaced the shower head (with a cheapo one from Wickes), plus it's a soft water area. Is there anything else I should look for?

You'd think! I have to get a more senior surveyor involved to make sure there's no 'corruption'.

[Dave Plowman (News)]

Glad you've learnt from me the difference between pressure and flow...

[Dave Plowman (News)]

So an electric motor driving a pump needs to be expensive, but when driving a power tool the cheaper the better? Think you've not thought this one through again...

You guarantee 4 bar off the mains?

You are all the time.