Shower bath mixer tap woes

[Andy]

Hi,

I've got a problem with my 1st floor shower. It's an in-bath, shower head on flexible hose connected to the bath mixer taps type affair. House built in 1990, all original plumbing - conventional setup for that era i.e. stored cold water tank in loft, HW cylinder in airing cupboard on 1st floor. The shower in question is gravity fed from pipes leading from the airing cupboard. The problem is the appauling flow rate of both HW and CW, but especially CW through the bath mixer taps. Even with the shower turned off the CW output from the bath taps is pathetic, the CW output from the wash basin in the same room as the shower is substantially better as is the performance of another shower (also gravity fed) in an en-suite of a different room on the same floor. My numero uno culprit for the poor flow is the non-return valves (check valves) fitted just before the bath mixer taps. The picture below shows the scene with the bath front panel removed. The two pipes feed the HW/CW bath mixer taps and the two valves are presumably the two check valves ?

guess the check valves are there due to water regs required when a shower head on a flexible lead is used in a bath environment with the potential for drawing contaminated water back into the house water tanks/supply.

So, what to do.......

I was thinking of something along the following:-

1. Try to prove that it's the check valves which are responsible for the poor flow by measuring the CW flow with valve in place, removing valve and then measuring the new flow rate.
2. If the flow rate differences are substantial then remove both check valves and replace the flexible hose shower with a fixed head unit. I was thinking of the following retro-fit unit from Screwfix :-

as the shower head would then be fixed and so couldn't be submerged in contaminated bath water then I'm OK regarding water regs with removing the check valves ?

Things I'm not too confident about:-

Removing the check valves and fitting a new connector from the pipe to the tap. Presumably the bit of the supply pipes where the check valve compression olive has bitten will not be reusable for fitting a new connector and I'll have to cut away some pipe and either fit a new compression joint to a fresh bit of pipe ?

Any comments, suggestions ?

Andy.

[John Rumm]

If the shower is gravity fed (i.e. HW from the cylinder and CW from the header cistern in the loft) then there is no need for any sort of non return valve in the setup.

aren't mind you ;-)

(I think your equi-potential bonding ought to be on the other side of the valves as well)

Since you are not suppose to drink the tanked water it is a bit of a non issue. The time a double check valve would be required was if there was a danger of contaminating the rising main.

Sounds like a good plan...

As long as your new compression fitting is the same thread as the existing (highly likely), just reuse the existing olive and back nut. Add a few turnd of PTFE over the olive if in doubt or try sealing compound like Fernox LS if you prefer.

You will need a little bit of play in the pipes to get the old valves out. If they are fixed rigidly, then cut away the valve with a pipe cutter, and use a soldered slip connection to make the last joint.

[Andy]

Perhaps I'll step back a bit and ask if anyone can identify these valves then ?

I'm assuming they're check valves, anyone confirm this ?

Here's a closeup :-

Andy.

[John Rumm]

small axial plunger on a stalk with a spring, flow in one direction pushes the plunger away from the seat and allows water to flow, in the other direction it pushes it into its seat and prevents flow, with no flow the spring returns the plunger to its seat.

Either way, if its a gravited fed shower on both hot and cold then you won't need a check valve.

[Andy]

Thanks for your help again John. Yes both CW/HW supply is gravity fed so I think it's the end of the road for the valves!

As you mentioned in your previous reply though, actually removing the valves could be a bit tricky if (as I suspect) there's no movement in the

22mm pipes either side of the valve. You mentioned cutting the valve out and joining the two pipe ends with new pipe and solder connectors. Wouldn't I have the same issues with pipe rigidity when assembling such a connection setup i.e somethings got to give to allow the pipe to be fitted inside a solder connector....

Sorry for the basic questions, new to this plumbing lark!

Cheers,

Andy.

[John Rumm]

Removing will be dead easy, rather than bothering to unscrew the nut, just cut the pipe above and below the valve. One of the small pipe cutters should fit in between the pipes ok. Having said that you may find there is play in the pipes anyway, especialy as the top section of each pipe has a dog leg in it.

You you are right, the key word in my original suggestion however was "slip"... as in solder "slip connector". These are like ordinary solder fittings except they don't have the depression in the centre that stops them sliding right over the pipe. Hence as long as you can get a pipes thickness of lateral movement out of at least one pipe, you simply flux it up, slide it right onto the pipe so that it does not overlap the end, re-align the pipes, and slide it half way back again before soldering. You can achieve the same result with a compression fitting if you want by drilling out the stop in the middle of it so it will pass right onto a pipe (tricky without a big drill bit and a drill press mind you!) If you really don't fancy that, then you could use a couple of push fit elbows and a short section of flexible plastic pipe instead.

[Andy]

Cheers again John, I worked out what you meant by slip connector about 15 mins after posting my last message :-) Simple solution really! I think I might do some practice solder joints on a spare pipe and connectors first.... How do you keep the copper slip peice in place when applying heat and then solder to a vertical installation (assuming only one pair of hands are available!) ? Presumably gravity will make it slide down the pipe ?

Andy.

[John Rumm]

Often the way... bit like sometimes it is only half way through explaining something to someone that you suddenly "get it" properly yourself!

With a bit of luck it won't be that loose. If it is, you could give it a gentle squeeze with a pair of grips to tighten it on the pipe first.

[blue.element]

-- blue.element