I have just ripped out a Triton power shower and want to replcae it with a thermostatic mixer shower tower. I am left with a cold feed which comes directly from its own tank situated in the loft. I'm thinking this feed will not provide enough pressure without a pump as according to the gumpf I need 2.0 bar at least. The tank is about 3 metres above where the shower will be.
My question is can I tee off the feed into the hot water cylinder for the cold supply and Tee into the output of the Hot water cylinder for the hot?
That's what I did and it works perfectly for me. Be careful when choosing a pump - if you want several showers in a row (mum dad and 2.5 kids) then choose a 'continously rated' one.
No. Doing this will likely starve the hot water cylinder of supply, leading to air in the hot line. Use either a dedicated line from the tank (which you appear to already have), or use mains cold and only pump the hot (assuming your mains cold line is good).
This is sometimes possible. I have successfully used this method. It does depend on the supply to the cylinder being very good, with at least 22mm pipework, flowed bends and full bore valves from a cold tank situated nearby. However, the correct technique is to install a flange, which will dramatically reduce the risk of air being send down the line. You can install on the standard hot outlet and then only install a flange if problems are encountered.
Do it properly, feed from loft tank, flange in HW tank. If you do no matter what anyone else does with water in the house, turn on taps, flush loos etc your shower will be unaffected.
My two experiences of "bodged" shower pumps are:-
- Pump, under bath connected to bath cold/HW supply. Reasonable shower, until you opened a hot tap upstairs as well and it sucked in air via tap and end of shower, as it started blowing hotwater, cold water and air !!!
- Hot feed from expansion pipe and cold feed from HW tank cold feed to pump. Again pump would pull water out the expansion pipe and in this case just blow cold water and air.
Both the above worked sometimes, ie you got a decent shower, but the slightest upset, flushed toilet, accidently leaving bath tap on a bit and you instantly got air in your pump, making it a complete waste of time trying to take a shower till all settled again.
I did it properly in all the power showers I have fitted, cold feed from lowest point in loft tank and flange fitted to HW tank. One flange I screwed into top of tank, where expansion pipe exits and another time need a 25mm (?) hole in side of tank.
Just my tuppence and clarification for those that don't appreciate this: Ian's suggestion of taking the cold feed from the lowest point in the loft cistern is to ensure that when your mains cold supply fails whilst you are in a helluva long shower (only for dirty folks of course) then the cold supply to the hot tank runs out of water first before the cold supply to the shower does. So you get a cold shower, not a scalding one.
Hope I don't get flamed for elaborating further Ian; good works otherwise.
Mungo :-)
P.S. Yep, I too call it the "cold tank" in the loft but Matthew Marks would insist it be called a "cistern". What's happened to Matthew these days anyone?
Ok thanks for this. I will use existing cold water tank that was used for the old power shower for the cold supply and flange into the cylinder for the hot. I will pump both supplies. I'm assuming the cylinder is what was meant by the hot tank in Lees response?
Anyone recommed a decent pump and I'm assuming this could be fixed in the loft space somehow.
not cheap from Jayhards in 2001, probably quite a big one as my current house has two ensuite showers (probably the QT120), can't remember, never really looked at it since installation. Anyway powers two showers without and significant loss when 2nd shower is turned on. It is located on floor or airing cupboard and a pile of carpet to deaden noise and connected into the existing copper pipework using Hep2O plastic plumbing stuff. Luckiliy our new house was plumbed with the showers feeds already connected to loft tank and HW tank, just needed a pump "inserting".
Don't place pump in loft, my last house had this initially, problems are:-
- It vibrates the whole ceiling/roof/house no matter what you did.
- Occupies quite a bit of loft, in my case just next to loft hatch and was "in the way all the time" when in the loft.
- Suffered very badly with air locks after say leaving for a couple of days.
Plumber moved it to shelf in airing cupboard, but you loose shelf space and still had air locks in hot side so I ended up moving it to floor of airing cupboard, put a self venting air vent in the hot feed and never suffered any problems again.
Cheers Ian. Just to be double sure, when you refer to hot water tank this would mean HW cylinder in my speak? my HW cylinder is actually in the Loft! so I'm assuming I should not suffer from airlocks but I will fit self venting air vent in case. One other thing, if I have good mains water pressure should I consider just running the shower from this and not bother pumping either supply?
I found the type of flange where you have to drill a new hole was easier in my case. To remove the old coupling at the top of the cylinder was non-starter, its right under a shelf anyway. I think the one I used was made, like my pump, by Stuart Turner. More info here:
I mean HW cyclinder. Look on the Techflow site, there are plenty of diagrams to look at an try to match to your setup. Techflow even do a sutable HW tank flange.
All this messing around is done to provide decent flow to the pump that is going to be unaffected by flushing toilets, running baths etc etc and if you do it right it works fine.
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