How to increase bathroom water pressure?

[nagumuthu]

Hello Members,

Good Morning.

May you propose ways to increase water pressure on showers. The pressure is dropped under circumstances where both showers were in use / water is drawn at sink.

Can the purchase for the pump from Bunnings shall be made and fitted. Should the council be informed for such activity. [ I might be more cautious here ]. (or) the Job should be completed by any licenced plumber ?

If anyone have performed above task, can you please share the budget incurred.

Many thanks for your time.

Best Wishes

MM

[EricL]

Hello @nagumuthu

Thank you for sharing your question about how to increase the water pressure in your bathroom.

If you are after an overall increase of pressure inside the house you will have to install a pressure booster. However, several conditions must be met before you attach the pump to your house. 

• You will need a registered plumber to assess your plumbing and attach the pump to your house.
• The plumber will have to make sure that your current plumbing can take on the higher pressure, otherwise, it will cause leaks in your current system.
• You will need to make sure that adding the pump to your house is legal. You'll need to look at the council rules in your area and consult your plumber about it.
• You will possibly need to have a water tank as a header for the pump.

One of the other ways to get better pressure from your shower is to change the showerhead to one that is rated for 9ltrs. You can also instill water discipline in the house. When someone is in the shower, no other taps must be turned on until the person having the shower has finished. This will of course will involve total cooperation from all the members of the household. It sounds like a very interesting addition to your plumbing system. 

Please keep us updated with your progress, we look forward to seeing the pressure pump attached and working.

Let me tag our experienced members @TedBear and @Brad for their recommendations.

If you need further assistance, please let us know.

Eric

[TedBear]

Hi @nagumuthu , I agree with @EricL on this. It is normal to not be able to run 2 showers at once plus a 3rd tap on domestic household plumbing. In addition to the suggestions offered, you could enquire with a plumber about having larger pipes installed from the meter onwards to feed the showers, but that could be an expensive way to solve the inconvenience and may not offer much improvement.

The other thing to question is, what type of hot water system are you using? That could be a source of restriction on the maximum water flow to the showers and the loss of pressure when attempting to draw more water than it can supply at full pressure.

If you are on mains water, have you checked that your water meter tap is fully on? (Should be on full, then backed off a quarter turn... to ensure the threads don't seal in the on position and be near impossible to turn off in an emergency.)

[nagumuthu]

Hello Eric,

Thanks for the quick response.

Is there a way to find what rating for the current shower head for a check and approach plumbers  as recommended (if the shower head suits 9L rating). I could not see any engravings on the shower to indiate its spec.

[nagumuthu]

Hello Ted,

Thanks for your reply. Let me check and get back to you on informations related to water heater, as it is dark now.

[EricL]

Hello @nagumuthu

One way to measure the amount of water coming out of your shower head is to use a 1 litre measuring bowl. Use a stopwatch to count the number of seconds it takes to fill the bowl. Take the 1 litre measurement and divide it by the number of seconds it takes to fill the bowl. You then multiply that answer by 60 which will give you the number of litres per minute.

For example : ( 1 litre bowl is filled in 10 seconds, 1 divided by 10 = .1 ) we then multiply .1 x 60 = 6

• This means that your shower head puts out 6 litres a minute.  

Once you find out your litres per minute, then you will really how slow your water is.

If you need further assistance, please let us know.

Eric

[nagumuthu]

Hello Ted,

Here are the information in relation to Water Heater and Mains Water. Do I need to contact the water heater vendor for infering the flow rate of the equipment.

I could not find any hand valves on Mains Water. Am I looking at different location..?

Thanks

MM

[nagumuthu]

Hello Eric,

Measurement data as follows.

With the shower knob turned to the extreme end (1L = 12.33 secs). That equates to 4.86 L/min

With the shower knob turned to other end extrement (for hot water purpose) (1L = 11.78) which equates to 5.09 L/min.

On average for computation, we can consider the water flow rate as 5L/min. 

Few thoughts to infer where the bottleneck is.

1. Can the mains supply water flow be measured through an instrument.

2. Can the flow rate be measured before and after the water heater to infer the bottle neck is due to the heater equipment.

Thanks

MM.

[EricL]

Hello @nagumuthu

Yes to both questions sir. However, you will need the services of a registered plumber. They will probably have this instrument in their ute. As an experiment, you could try and measure the water flow from the tap that is closest to the hot water cylinder. If you get the same result you can safely conclude that the bottleneck is happening after the hot water cylinder. But, if the water flow is greater, then there is something blocking or slowing the water down before it reaches your shower. I suggest testing the rest of the house and gathering some data.

If you need further assistance, please let me know.

Eric

[TedBear]

Hi @nagumuthu 

I see from your photos that the water valves appear to be fully on. They are the levers just to the left (in the photo) of the meters.

I also notice that your hot water system is an "instantaneous"  (aka Continous Flow)  Rinnai B26.

The specs on that are that they can deliver (at 50° C) a maximum of 13L/min. 

(And will need a minimum pressure of 200 kPa to do that, but pressure may not be your problem. It will take testing by a plumber to determine that.)

So, if you run 2 showers each drawing 5L/min, then you only have spare capacity of 3L/min for a tap.  If the tap user also wants 5L/min then the HW system will not be able to deliver and all outlets will drop in order to maintain the maximum of 13L/min throughput.

That is assuming that everything is working perfectly and the minimum pressure is available.

But the fact that you can run 2 showers and only run into problems when a tap is also turned on, suggests that the HWS delivery limitations may be a contributing factor to the  problem.