Second shower has much lower pressure

[smithfield11]

We’ve just bought a new house (new build). The main bathroom shower above the bath is extremely powerful however the rainfall AND handheld shower in the en suite are significantly lower.
They’re both mains fed showers from a new 35kw combi.
I can’t work out why one shower would be so poor when the taps and shower elsewhere are much better in the rest of the house.
Any advice much appreciate, thanks in advance.

 

[John.g]

Do they just feel less powerful at the same showering temperature?, a 35 kw combi will provide a flow rate of 14 LPM with a 35C temperature rise and should give nearly 17 LPM from cold water at 10C (just now) with a showering temperature of 40C. There may be flow restrictors fitted in the en suite showers.

 

[smithfield11]

Do they just feel less powerful at the same showering temperature?, a 35 kw combi will provide a flow rate of 14 LPM with a 35C temperature rise and should give nearly 17 LPM from cold water at 10C (just now) with a showering temperature of 40C. There may be flow restrictors fitted in the en suite showers.

Yes, it's definitely a subjective "feel" however than hand held head on both, when on full power at the same temperature:
- In the ensuite pointed horizontally the hand held head will express water less than 2 feet before it's falling vertically
- In the main bathroom the hand held head will express water the length of the room (8 feet+) without any noticeable dip

I'll need to check re: a flow restrictor but not sure how to do that.

 

[Ben-gee]

Blocked filters in the shower inlets, or partially closed valves?

 

[smithfield11]

Blocked filters in the shower inlets, or partially closed valves?

Ill have a look at how to check this. Just trying to get a feel for if this is likely something fundamental (I.e the boilers crap or the pipes are wrong) or if it’s something wrong with the setup of the shower

thanks for the input

 

[John.g]

Yes, it's definitely a subjective "feel" however than hand held head on both, when on full power at the same temperature:

• In the ensuite pointed horizontally the hand held head will express water less than 2 feet before it's falling vertically
• In the main bathroom the hand held head will express water the length of the room (8 feet+) without any noticeable dip

I'll need to check re: a flow restrictor but not sure how to do that.

There may be different size jets in the heads but one relatively easy test is to measure the flow rate from each by letting it (them) flow into a dish for say exactly 30 secs and measure this with anything suitable and X by 2, it saves a lot of toing and froing.

 

[smithfield11]

There may be different size jets in the heads but one relatively easy test is to measure the flow rate from each by letting it (them) flow into a dish for say exactly 30 secs and measure this with anything suitable and X by 2, it saves a lot of toing and froing.

Thanks, I'll pop back over to the house tomorrow and check this, will come back with the numbers. Out of interest why times by 2?

 

[John.g]

Because you require the flow rate in LPM (litres per minute) and you might get fed up with filling a one lire milk bottle 14 times instead of 7 times.

 

[smithfield11]

Because you require the flow rate in LPM (litres per minute) and you might get fed up with filling a one lire milk bottle 14 times instead of 7 times.

I've been to check flow rate. We have three shower heads:
- one hand held head above the bath (perceived high pressure)
- one rain head in the ensuite (perceived low pressure)
- one hand held head in the ensuite (perceived low pressure)

All feed off the same 35kw combi system.

- Hand held head above the bath: 12.45 LPM
- Rain head in ensuite 6.9 LPM
- Hand held in ensuite 7.95 LPM

So there's a notable difference being caused by something, any further advice much appreciated but it might be "get a plumber in and give him these numbers"

 

[Timmy D]

Can you test the en-suite handheld and rain without the heads?

Can you test the combined hot/cold flow from the en-suite basin?

 

[smithfield11]

Can you test the en-suite handheld and rain without the heads?

Can you test the combined hot/cold flow from the en-suite basin?

looks like you clocked it. Took the rain head off and got the same pressure, but then took the rain head gimble/adapter off and it outputs at 12.5 lpm

I’ve attached a picture as with a bit of trial and error it appears that the small orange piece is the limiting factor. With that in its low. Without it’ll doup to the 12lpm. Is it required?