Grohe shower problem !

Postby misery » Fri Jan 16, 2009 11:19 pm

have just installed a Grohe Avensys 34 041 mixer shower,the insruction manual regarding flow limiters is a bit confusing to a novice like me!.
I believe I have 3 bar mains pressure coming into the house the shower is running off a Heatline 28 kw combi boiler with a flow rate of 13 lpm .I am not overly impressed with the water pressure from the shower ,would it improve the performance at all if I remove the flow limiters,green in the cold and yellow in the hot and if so do I have to replace them with spacers?
Hope all this makes sense to someone and any advice would be gratefully appreciated.
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Postby plumbbob » Sun Jan 18, 2009 11:14 pm

There are so many makes of shower about, it is impossible to remember the installation of each.

If the flow limiters are the ones with a little green or yellow disc with a small rubber washer in, then I know the ones you are talking about.

Some makes of showers are designed to work on both low or high pressure as well as unbalanced pressures. So the regulators have to be fitted to balance the water feeds and ensure the hot flow does not exceed the combi capacity.

If you are experiencing poor pressure with the regulators in place, then probably the incoming mains pressure is not what you think it is, or the boiler output is not sufficient to heat the required water.

Try removing both restrictors, or try with just the yellow on the cold side if the shower temp is too cold. REmoving them is not going to do any damage, the only problem may be with achieving an even water temperature.

You shouldn't need to fit any spacers unless the wire strainers are not held in place properly.
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Postby misery » Thu Jan 22, 2009 9:38 pm

Hi Plumbob
thanks for your reply wife thinks shower has improved now although we are now getting a high pitched whirring sound in the pipework.I can only describe it like a wc cistern when very nearly full makes that same noise which builds up until cistern is full and water shuts off! Does this make sense do you know what noise am trying to describe and any ideas what this could be,?

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Postby plumbbob » Fri Jan 23, 2009 12:15 am

Well, it is probably has the exact same cause. When high pressure water flows through a small hole, it can set up turbulence which causes the noise you describe. I can't say I can recall hearing this nose from a mixer shower, but it could be the reducers being over zealous.

Have you made sure any isolator valves are fully open?

Maybe you should speak to the technical department at Grohe and ask for their advice?
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Postby TheDoctor5 » Thu Jan 29, 2009 2:21 pm

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