Hello,
I have quite low flow rate for my electric shower (a piddling 5L/min), and would like some tips or advice about how to solve or find the cause. I would like a flow rate of about 12L/min.
Here is my set-up:
Standard gas boiler (not a combi) in the kitchen, have cold water tanks in the loft, and have the hot water tank & immersian heater in one of the upstairs bedrooms.
Bottom of loft water tanks are 1 meter above the shower pipe.
Mira 9.5kW electric shower.
10mm cabling to the electric shower, and the circuit can handle up to 14kW.
Here is what I have found out so far:
Anglian Water measured the pressure and flow rate at the outside water meter at 2.2bar and 40L/min (which is very good).
Anglian Water engineer suggested the low flow rate was due to a corroded stopcock.
I replaced the stopcock which did not change the flow rate anywhere in the house.
I measured the flow rate at the stopcock under the sink to be 30L/min (ran a hose off it into a bucket. 7.5 litres in 15 seconds).
The mains pipe is a standard blue plastic 22mm pipe.
All the pipework after the stopcock is 15mm.
With all appliances turned off and all possible valves turned off, the flow rate at the outside tap is 18L/min.
With all appliances turned off and all possible valves turned off, the flow rate at the kitchen sink cold tap is 10L/min.
Distance between stopcock and kitchen sink is less than one meter.
The flow rate of the cold water tap at the bath is 12L/min.
The flow rate of the cold water tap at the bathroom sink is 8.5L/min.
The flow rate of the cold water inlet pipe into the electric shower is 5L/min.
The bathroom & electric shower is about 4-5 meters above the stopcock.
Between the stopcock and kitchen sink, the water flows through two 15mm isolation values (the standard ones with the flathead screw), and five 90-degree bends.
Can anyone suggest why there is such a drop (from 30L/min to 5L/min) in flow rate?
I have had a plumber suggest that a better flow rate could be achieved be replacing the 15mm pipework up to the bathroom with 22mm pipework. But he could not guarantee that after this work was completed that the flow rate would be any better.
So it seems a black art. Any suggestions welcome.
I have quite low flow rate for my electric shower (a piddling 5L/min), and would like some tips or advice about how to solve or find the cause. I would like a flow rate of about 12L/min.
Here is my set-up:
Standard gas boiler (not a combi) in the kitchen, have cold water tanks in the loft, and have the hot water tank & immersian heater in one of the upstairs bedrooms.
Bottom of loft water tanks are 1 meter above the shower pipe.
Mira 9.5kW electric shower.
10mm cabling to the electric shower, and the circuit can handle up to 14kW.
Here is what I have found out so far:
Anglian Water measured the pressure and flow rate at the outside water meter at 2.2bar and 40L/min (which is very good).
Anglian Water engineer suggested the low flow rate was due to a corroded stopcock.
I replaced the stopcock which did not change the flow rate anywhere in the house.
I measured the flow rate at the stopcock under the sink to be 30L/min (ran a hose off it into a bucket. 7.5 litres in 15 seconds).
The mains pipe is a standard blue plastic 22mm pipe.
All the pipework after the stopcock is 15mm.
With all appliances turned off and all possible valves turned off, the flow rate at the outside tap is 18L/min.
With all appliances turned off and all possible valves turned off, the flow rate at the kitchen sink cold tap is 10L/min.
Distance between stopcock and kitchen sink is less than one meter.
The flow rate of the cold water tap at the bath is 12L/min.
The flow rate of the cold water tap at the bathroom sink is 8.5L/min.
The flow rate of the cold water inlet pipe into the electric shower is 5L/min.
The bathroom & electric shower is about 4-5 meters above the stopcock.
Between the stopcock and kitchen sink, the water flows through two 15mm isolation values (the standard ones with the flathead screw), and five 90-degree bends.
Can anyone suggest why there is such a drop (from 30L/min to 5L/min) in flow rate?
I have had a plumber suggest that a better flow rate could be achieved be replacing the 15mm pipework up to the bathroom with 22mm pipework. But he could not guarantee that after this work was completed that the flow rate would be any better.
So it seems a black art. Any suggestions welcome.
Last edited: