Shower / combi boiler flow rates

22 Nov 2013
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United Kingdom
Hi all, I am just looking for some information on flow rates for my shower. I have a Worcester junior 28i boiler which according to the booklet provides 11.5 litres per minute of water. I have a Mira minilite thermostatic mixer shower running off it which according to the leaflet provided with it gives around 5 litres of water per minute (I did the bucket test at normal shower temperature and this is correct).

This might be a fairly obvious question but I assume if I get a different shower that can provide a higher flow rate (Mira seem to have several that can provide up to 12 litres per minute) I will get a better, more powerful shower?

It just seems a bit of a waste to have a shower that provides a relatively low flow rate when the boiler is capable of more.

Thanks in advance for any help
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The boiler is quoted at being capable of raising the water temperature by 35 degrees with a flowrate not exceeding 11.5 litres/min. Lets say the incoming cold mains is 5 degrees then with a flowrate of 11.5 litres/min you would expect the water temperature to be around 40 degrees (just sufficient for bathing). Turn the flowrate up and the temperature will reduce and vice versa.

Your shower has a flow limiter built in to comply with its "eco" claims. There is no need to replace the shower. You should be able to remove (or substitute) the flow limiter to give a higher flowrate. Having a quick look in the manual shows the flow limiter to be installed between the shower hose and the shower or wall connector.

Of course you will consume more water and gas with an increased flowrate but that must be balanced with perhaps a longer shower with such a limited flowrate as currently exists.
Many thanks for the reply gasguru - I will see about getting a different flow limiter to improve the pressure.
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It's there so the shower manufacturer can claim the shower is eco friendly, that's all.

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