Bath tap 'flow straightener' restricts flow

[essayer]

In the summer we had our bathroom done and they installed a Grohe Concetto bath mixer
The flow from it has always been duff and I blamed the fact we have a gravity water set up, cold tank in the loft and cylinder on first floor etc.

SWMBO was complaining that it had got even slower - and whipped off the 'flow straightener' to find it full of gunk - like like scale but slimy.

Anyway I noticed that if I took this straightener off, the water pissed out faster than George Best getting home from the pub, filling the bath far quicker than ever before.

It restricts the diameter by probably 50% plus has a few layers of fine mesh, so no wonder we get a slow flow.

You can see it here on the diagram,
http://cdn08.grohe.com/lib/1/tpi/1590364.pdf part 46162

So the question is, are 'straight through' flow straighteners available? Could multiple ones (LP/HP) have been included with the tap and the plumber just used the wrong one?

[bernhund]

Why not leave it out?

[SLCZ3]

I would suggest that you find out why there is so much gunk in the system.

[Pheo]

Isn't the flow straightener often an aorator to reduce water usage?

[z06tim]

I too thought it was more of an aerator, and normally these are only recommended for high pressure systems.

[essayer]

bernhund said:

Why not leave it out?

Without it fitted it splashes back over the tiled area at the back of the bath.

I'll keep an eye on why there would be the sludge in it, maybe it wasn't flushed through when it was first fitted? None of the other taps have exhibited this problem.

[bernhund]

essayer said:

bernhund said:

Why not leave it out?

Without it fitted it splashes back over the tiled area at the back of the bath.

I'll keep an eye on why there would be the sludge in it, maybe it wasn't flushed through when it was first fitted? None of the other taps have exhibited this problem.

That's quite likely I'd think. Quite a lot of crap can be dislodged when changing taps. Good make Grohe, should last forever.

[CorradoTDI]

Remove it and use a service valve to reduce pressure slightly...

[essayer]

Measured it now.. With the straightener cleaned out, both taps full gets me about 16L/min.
With it removed, 25L/min.

Seems like a big loss just to have 'straightened' flow !

[Gingerbread Man]

You often get high pressure and low pressure variants supplied with taps. The low pressure ones being freer flowing.

Without any you typically get a weird flow from the tap. But by all means use without one.

[northwest monkey]

CorradoTDI said:

Remove it and use a service valve to reduce pressure slightly...

This is the easiest & cheapest option. You can play around with it until you're happy then.

[Gingerbread Man]

northwest monkey said:

This is the easiest & cheapest option. You can play around with it until you're happy then.

It'll reduce the flow.

[northwest monkey]

Gingerbread Man said:

northwest monkey said:

This is the easiest & cheapest option. You can play around with it until you're happy then.

It'll reduce the flow.

I think that's what he wants to do.

[Gingerbread Man]

northwest monkey said:

Gingerbread Man said:

northwest monkey said:

This is the easiest & cheapest option. You can play around with it until you're happy then.

It'll reduce the flow.

I think that's what he wants to do.

I thought the original problem was too slow a flow rate. Running without a straightener typically leads to a queer flow from the tap. Using a service valve will reduce the flow, not the pressure. So you'd just be left with a service valve restricting the flow and no flow straightener to produce a nice spout flow as it were. So, gaining nothing?

High pressure flow straighteners typically are mesh. Low pressure versions are more of a plastic waffle construction.

Edited by Gingerbread Man on Monday 26th January 08:10

[Pheo]

I think the problem the OP has, is the wife wants the bath to fill faster. This means more flow, and removing any restrictions

However, the flow restrictor / straightener has been fitted to solve another problem - that of the jet of water being so powerful, it goes everywhere.

So which one does the OP want? Fast flow, but with it probably spraying everywhere, or lower flow, but more controlled? If neither, then look for a different tap.

[essayer]

As always, the OP wants a peaceful life, and the degunked straightener has achieved that so far. It would be nice to gain some small increase in flow rate (in hindsight buying a huge bath was also a silly idea)

I wonder if they are all the same measurements, which would let me swap some low pressure generic version off eBay..

[Neil - YVM]

essayer said:

Measured it now.. With the straightener cleaned out, both taps full gets me about 16L/min.
With it removed, 25L/min.

Seems like a big loss just to have 'straightened' flow !

Think you will find that around 15 ltr/min is what the manufacturer specs the tap at for a gravity fed system.

Might be worth contacting Grohe to see if they have a specific low pressure straightener.