HELP is there a PLUMBER in the house

[farmer]

just fitted new thermostatic bath filler/shower mixer tap and for ease of fitment I've used flexi Tap conectors with service valve combined (500mm long 22x3/4"fitings screwfix part no d35826 issue 77 page 288)I had a leak in one of the valves and Screwfix are sending another , my problem is that the cold flow from the one I have connected is very poor , so I'm wondering if the flexi pipe has restricted the flow too much, or is it just that the cold feed for the bath coming from the loft tank (rather than mains pressure) hasnt got enough pressure to operate the thermo valve in the tap , or am I just going to have to fit the (hopefully) better new flexi to the hot side and see what happens when I srike it all up . Other alternative is a pump I suppose ?
any advice greatly apreciated

[Wacky Racer]

Ferg!!!

[sparkythecat]

These valves are really designed for use with combi-boiler or pressurised water heating systems.
If you are on an older conventional heating system, then you are right - the cold feed to the bath will probably be from the header tank in the loft and so you will need to pump it.
To check if your bath cold water is actually fed by the header tank in the loft, turn the cold main off - usuually under the kitchen sink. Try the bath cold tap and see how it runs. If there is no discernable reduction in flow then it's fed by the header tank and will only stop running when the tank empties

[farmer]

sparkythecat said:

These valves are really designed for use with combi-boiler or pressurised water heating systems. If you are on an older conventional heating system, then you are right - the cold feed to the bath will probably be from the header tank in the loft and so you will need to pump it. To check if your bath cold water is actually fed by the header tank in the loft, turn the cold main off - usuually under the kitchen sink. Try the bath cold tap and see how it runs. If there is no discernable reduction in flow then it's fed by the header tank and will only stop running when the tank empties

thanks for the reply
yes it's definately from the header as I have to turn it off in the airing cupboard . the tap itself is Italian http://s85569719.oneandoneshop.co.uk/sess/utn;jsessionid=154202cc79e3632/shopdata/0010_Bathroom/0010_Bathtub/product_details.shopscript?article=0170_Bath%3D26slash%3D3Bshower%2Bmixer%2Bmodel%2BBirillo%2B%3D28TOT10532%3D29 looks like I'd better see if it works on standard pressure and if not get a pump.
how noisy are they?

[ntel]

You say that only the cold flow seems to be restricted. The hot water cylinder will also be fed by a cold water storage tank in the loft and therefore the hot and cold water pressures should be balanced. If the hot water flow is better than the cold water flow then I would suspect that the is a restiction in the cold water feed to the tap. If this is the case then check the hose isnt kinked and that any valves in the line are fully open and not blocked.

The mixing valve should have come with installation instructions. These will specify the minimum head required to operate the mixing valve correctly.

[ferg]

I'd agree with most of that. Check the instructions, most of the brassware we use now comes from Italy etc where high pressure hot and cold is the norm. As unvented systems become more common more taps like that are sold. Bear in mind 1bar is approx. 10 metres head. Also, like ALL real plumbers I think rubber hoses whether stainless reinforced or not are crap and shouldn't be used.

[farmer]

I'm still awaiting a replacement for the flexi on the Hot side from screwfix that was leaking out of the screw when openned . Sadly the instructions are absent or in Italian such as they are , my poor-to-cr@p schoolboy Latin doesn't help. So yes the two are balanced , as far as I know so far . Obviously Flexi's are a compromise but will the narrower bore reduce the flow? Am I better to struggle to put a 22mm service valve in and re-use the old solid pipes suitably shortenned to fit . The problem then is that if the output pressure isn't good emough to operate the tap in the first place , then I need to fit a pump and use flexi's anyway ...Yes?

what is the noise level like on these-ere pumps ?

thanks for the input so far O'learned ones .

[ferg]

Er, where to start?

Flexi pipes do restrict and they also twist and distort...and leak and even burst. You will need flexible hoses on a pump, but they are a whole different ball game quality-wise. Hoses on pumps should never be bent further than a few degrees from straight, they are there to take the vibration out not to make plumbing easier. Isolating valves can also be a nightmare...use full-flow lever valves or gatevalves, 'ballofix' valves or similar will typically have a bore of around 15mm on a 22mm pipe.

If you feel the need for flexible plumbing, and I'm not being clever with that comment, try 'Speedfit' from John Guest. It isn't as flexible as the stainless hoses, but 100% (ish) reliable and they do a 22mm tap connector with an 'o' ring which swivels.

[farmer]

Thanks Ferg

There is a (Graded stock) shower pump coming up on Ebay in a while would that be a good investment anyway ( assuming It is a good pump I'm not asking for you to warranty it)

[Ferg]

Ian,

My only pump advice would be to beware of the installation instructions. Some manufacturers will stipulate dedicated cold AND hot supplies to the pump. Cold is quite important since the potential to upset the balance EVEN with a thermo-shower is always a possibility resulting in scalding. Hot, however, can cause problems from a plumbing point of view in existing situations. Some manufacturers will want the pump to be first tee off the hot supply, others will want a flange (stop sniggering at the back there boy!) in the cylinder, either Essex or Surrey. If you don't do it and it fails they'll walk away from any warranty claim that may occur. Some are easy going...Aqualisa tend to be quite realistic. Salamander not so.

[farmer]

Ferg

looks like the one I'm looking at needs 2.3 metres head above the shower head to work so that rules it out unless I stick the header tank on the top of the chimney, so I'd better stick to plan A at the moment.

[Ferg]

farmer said:

the one I'm looking at needs 2.3 metres head above the shower head to work.

Surely some mistake. If you had 2.3 metres above the shower head you wouldn't need a pump!!!! They usually like 300mm or so just to get the flow switch to operate.......

[farmer]

Does sound excessive , but only going by the dear old Screwfix catalogue page 327 issue 77 it probably should read 2.3 above the pump not shower head

stop press I read it wrong it needs 230mm

>> Edited by farmer on Saturday 12th February 15:49

[Ferg]

I think your best course of action is trundle along to an 'independent' plumber's merchant and ask for their advice based on the information you have.

1. It's to boost a bath/shower mixer.
2. You want to site it under the bath on existing feeds.
3. You don't want to run dedicated hot or cold.
(This may scupper you if your cold is supplying anything else. Having said that if it's only the toilet and basin in that bathroom you may want to take that chance.)

Then get price, compare with 'Net, take into consideration the possibility that you may want to take it back and/or tap them up for info and purchase.

[GregE240]

I was going to post a similar thread, but as ones open already....

I have a Mira Excel shower mixer in my ensuite, and the water pressure has been getting steadily worse over the last months. The mixer unit is an exposed one, 90's vintage, like this one:

www.showerdoc.co.uk/spares/mira/mira-excel-old.htm

If anyone has worked with these before, any idea on what it could be? Are there filters which need cleaning, and never have been?

For the record, I have both mains cold water and the hot is served at mains pressure. The hot tank is a Megaflo and hot water pressure everywhere else in the house is astonishing. I have the same Excel mixer in the downstairs shower, and that hurts if you turn it on too much, such is the water pressure.

Any advice offered most appreciated.

Thanks,
Greg

[farmer]

Thanks very much for all your kind advice Ferg (et all)the cold suply is just to the bath, the toilet and basin are Mains pressure.

I'll give it some thought/seek advice , but who knows the shower may work fine from the loft tank we shal see ,

kind regards
Ian

now off to buy a Valentines card and Chocs for the boss
catch you later

[Ferg]

Blimey it's aright old shower-fest on here!

Strainers visible in your exploded diagram, check those first. I can't remember if there are flow restrictors, but I suspect there are possibly in the inlet elbows. These are normally fitted with unvented hot supplys often with a different one in each side depending on whether it has been fitted with a 'balanced' cold supply out of the cold port on the Pressure Reducing Valve on the cylinder.

[GregE240]

Cheers Ferg. Quick reply sir!

Its not going to be the flow restrictors though, is it? They'll have been in there since day one.

Will dismantle the thing and see what state the strainers are in.

Thanks again,
Greg

[Ferg]

GregE240 said:

Its not going to be the flow restrictors though, is it? They'll have been in there since day one.

Sorry I didn't elaborate there.

The flow restictors are often a little plastic disc made up of different layers and they collect scale quite effectively. If it has any they may well have blocked up.

[GregE240]

Cheers for the clarification Ferg.

Shame you're not nearer to me mate, the job would have been yours.

Seems like a bit of home plumbing is in order....

Thakns for all your help,
Greg