shower plumbing

Discussion in 'DIY' started by Grumblegrunt, Nov 30, 2012.

Welcome to the Army Rumour Service, ARRSE

The UK's largest and busiest UNofficial military website.

The heart of the site is the forum area, including:

  1. Grumblegrunt

    Grumblegrunt LE Book Reviewer

    being in a new ish house they have done the usual thing of tanked hot water and an electric shower. this time of year the shower is pretty chilly due to the mains water temp and header tank temp.

    I'd like to keep the electric option but want to try a standard tank fed shower. so it doesn't look too odd I think a fixed rain shower head in the ceiling with a valve tucked away somewhere.

    one thing I am wary of is tank head pressure not being up to the job but I don't particularly want to install a pumped solution yet. can anyone think of an easy way to test it and indeed up the pressure if required. its piped in plastic for the most part so easy enough to patch into. the tank cupboard is next to the bathroom.
  2. Get a mains cold feed to a suitable shower unit if you can, problem solved.
  3. Grumblegrunt

    Grumblegrunt LE Book Reviewer

    its got that in the exisating leccy shower. its only 9 odd kw but not broken so no point changing it yet.
  4. likely be cheaper to change it that do the mods you are thinking of and you can always sell the unit you take out
  5. If you get the shower changed make sure the cabling is actually up to the job and the correct rating, I've seen a few DIY jobs recently where the cabling is not up to the required standard and things have started to get a little warm and it's not the water.
  6. If it's a newish house, you'll probably have a shallow roof, so you won't have the head to raise the tank to get decent pressure.

    A good shower pump requires a lot of water up in the loft, usually 3- 4, 40 gallon tanks.

    Stick with your little shower for now and aim to swap to a combi boiler..... that's the better option in the long run.

    I've just put a tap/ shower combination on the bath and we get a great shower.
  7. I don't like the electric showers as they are always a balancing act of cold high water speed/pressure or a hot dribble. I used to put in the Wickes power shower for my houses and for any punter who wanted one - used to take me a morning.

    Position the shower on the wall - make sure you pre-wire it so you can just run the wire back to a double pole switch,
    Tap into the cold water cistern using a speedfit cistern connector,
    tap into the hot water feed from the tank in the airing cupboard - quick with a sppedfit or slower and cheaper with copper,
    run the pipe connect with copper or speedfit,
    the shower unit has built in push fit connectors to push the pipes into,
    run the cable and connect to a double pole switch - check current electrical regs.

    Doddle of a job.

    Power Showers - Showers -Bathrooms - Wickes
  8. A hot water storage cylinder, as you've got, with an immersion heater. The immersion heater will heat water in the event of a boiler failure, but it usually costs more in p/kW hr than gas.

    If you're content with a gravity fed shower, I'd stick with that. You can only increase the pressure with a pump which are invariably noisy. You need to ensure the pipework is done in accordance with the pump installation instructions, with the hot water draw off through an Essex/Warix/Surrey flange on the cylinder.

    You could use an unvented cylinder and use the water supplier's pumps instead of installing a shower pump. The supply pressure may be inadequate or the supply may be through a 1/2" pipe, which in adequate for a continuous trickle into a storage tank but inadequate for a powerful shower. It needs to be checked (pressure and flowrate) before committing yourself. IMHO, they're over-rated, the pressure is only useful for a power shower, a gravity supply from a storage tank is adequate for everything else.

    You can get mains pressure from a combi boiler. I don't like them, I think they've been missold more than PPI. All the boiler and water system components are shoe-horned into the boiler casing and there will be maintenance problems. The secondary heat exchangers scale up in hard water areas. They have their uses, mainly in flats.
  9. If you are considering on buying an MIRA power shower, check out both B&Q and WICKES own branded showers.

    These are some times made by MIRA and the only differents other than being approximately half the Mira price, is the quality of the shower head and hose.

    My house was fitted with a MIRA shower when built 15 years ago, and the MIRA lasted 2 years. Since then I have fitted 2 replacement showers, 1 from B&Q & 1 from WICKES. All the pipe work, electrics etc matched up just the front cover had B&Q or WICKES logo instead of MIRA.
  10. Grumblegrunt

    Grumblegrunt LE Book Reviewer

    the question is whether I can get enough pressure to have a gravity shower without resorting to a pump, hence the head question. mains temp in winter obviously means the leccy shower is on 8 instead of 5 to get a decent temp but you lose flow so its like using a camping shower at times.

    I think I will end up having to pump at least the hot.

    years ago I ran a multipoint water heater in the flat which ran on mains pressure very well and being in the bathroom you could turn the boiler to a decent water temp which gave volume without using too much gas. :)
  11. Not sure how our house manages it, but we have an electric water heater in the garage and a powerful, hot shower upstairs. No storage tanks at all (this is France, where header tanks are unknown). What we don't have is one of them thingies to drop the water pressure. Never measured the pressure, but it's probably way above what it's supposed to be (the standard over here is 3.5 bar).

    So clearly the pressure is provided purely by the main. Dunno if this helps ...
  12. Yes, if you pick the right mixer and do the pipework properly.

    But then peoples' expectations of a decent shower vary. Europe and the USA have usually used mains pressure fittings, so they expect a shower that resembles a hot pressure washer. The UK has traditionally used storage cisterns, hence the 'English drizzle' showers.

    Use a twin impeller shower pump (motor with a pump on both ends) to pump hot and cold. You'll have problems trying to get a mixer to work properly with different pressures.
  13. I went for the Megaflow option, all taps in the house (hot and cold) at mains pressure and the toilet cisterns the same. Not had any problems with showers since then.
  14. Several issues getting European style powerful showers in the UK:

    1. Water mains pipework is still in many cases beyond its sell by date having been installed pre-WW2. Most parts have been upgraded but there is still work to be done. Meaning water companies cannot increase the pumping pressure to dwellings in case they blow mains pipes.

    2. The British method of construction where a cistern is placed in the loft as the reservoir for the hot water cylinder and in some cases the cold feed. Having a cistern 12" - 18" above the head of a shower is never in a month of sundays going to give a decently voluminous supply of water.

    3. Flaggie stated that local pressure across in France is at around 3.5Bar. It is also that in many locations in the UK if you get a pressure testing valve onto a tap to check the pressure - that is if the area has been upgraded from vintage legacy water mains. In Europe they operate on mains pressure, no cistern in the loft, just direct mains pressure to drive the water through. In some places they use the unvented hot water cylinders which are capable of taking mains pressure hot water. Or, in flaggies case they use a method of direct heating of the water as it passes through to the outlet - but, I'll bet you can't buy the same electric heater in the UK that Flaggie has in France.

    It is very difficult to instantly heat mains delivered water in northern europe and have a decent flow and a decent teperature. The direct heating of mains delivered water was first started down in mediterranean Italy where the latent temperature of delivered water is higher than in the more northerly climes. Then some bright sparks decided that combi's and the like were a good idea and started selling them up north. However, there are people who like their combi's and would'nt have any other system.

    In a standard British house, with a standard British indirect hotwater system (cistern in loft) the optimal solution for a decent powerful shower is the power shower.

    S'what I said, more or less. You are right the hoses are kak, heads you can get away with, I always used to replace the piece of white hose pipe tha came in the box for a longer purpose made stainless shower hose.
  15. Onetap, have you checked out the Intergas combi's?

    I'm a big fan, 4 moving parts, no secondary heat exchanger to block up, just fitted one in my house and my mother's, no real issues after 5years of fitting them.


    The heating and domestic hot water are in 2 seperate coils embedded in the back of the combustion chamber, which explains their simple construction, and the 36kw model gives almost mains pressure without the added expense of an unvented cylinder.