Mira Combiflow Shower - flow rate lower than at the taps

[richardc1983]

I have the above shower. I get flow rates from the cold and hot taps of the bath and kitchen at 12ltr per minute However from the shower with the shower head removed I get only 10ltr per minute. This makes no difference if it is on full cold or full hot. The bath taps are connected to the same pipes that feed the showers.

I have cleaned the strainers and removed the 8ltr per minute flow limiter on the hot side (there isn't one on the cold side) but the flow rate is still exactly the same.

Any other idea what could be reducing my flow? The system is fed from a combi boiler but as I said the flow is the same on cold as it is on hot.

Would it be worth me removing the strainers/filters completely as there is a strainer on the shower head that protects from muck.

 

[PrenticeBoyofDerry]

could be debris in the pipework or fittings, or scaling of pipework.

 

[richardc1983]

could be debris in the pipework or fittings, or scaling of pipework.

Pipe work is plastic and only 5 years old, no scaling either and would expect the strainers to have been clogged before anything else but they were clear.

Is it ok to run the shower without the strainers I wonder if that is holding the flow back a bit. As I say it's fine from the bath taps and every other tap in the house.

 

[Madrab]

The strainers are to guard against any debris entering the mixer valve that would prematurely wear the ceramic valve.
Has the flow rate changed recently and that has now driven you to check the shower or has it always been this way?
BTW, according to the MI, if using a combi then the 8ltr/min regulator should be fitted. This will be to avoid hot water temp fluctuations IWT.

 

[richardc1983]

The strainers are to guard against any debris entering the mixer valve that would prematurely wear the ceramic valve.
Has the flow rate changed recently and that has now driven you to check the shower or has it always been this way?
BTW, according to the MI, if using a combi then the 8ltr/min regulator should be fitted. This will be to avoid hot water temp fluctuations IWT.

The flow rate has been like this since we got the house really but isn't as powerful as our friends who are on a meter of the road. We don't have a water meter.

Yorkshire water have just been out and they have done a flow test and say there is only 10ltr per minute coming into the house when there should be 12 so they are going to replace the stop tap and pipe out side to a modern spec to see if this makes a difference.

 

[Madrab]

Metered or not shouldn't really make a difference, hope they don't fit one for you now they have been out
Raising the flow by a couple of ltrs per min may give you a little boost though ultimately the shower flow will be governed by the max flow rate that your boiler can deliver hot water at. What type of boiler do you have?

 

[richardc1983]

Metered or not shouldn't really make a difference, hope they don't fit one for you now they have been out
Raising the flow by a couple of ltrs per min may give you a little boost though ultimately the shower flow will be governed by the max flow rate that your boiler can deliver hot water at. What type of boiler do you have?

They had better not! Lol

I have a gloworm 30cxi capable of hot water at 14ltr per minute. What is confusing is that the flow remains the same 9ltr per min on full cold or full hot so it's almost as if something in the shower is restricting it.

I've called mira as it's still under warranty and they are going to come out and check it over.