New concealed shower pipes question (does thickness matter?)

[Live&Learn]

Happy new decade all!

I'm having my bathroom redone and it's getting there. I have recently changed to a combi boiler (Greenstar 30i) and my water rate is 11 litres a minute.

I'm having a walk in shower and I wanted a concealed thermostat. The builder said that was fine but suggested an external unit because his previous clients had been burned because when their thermostatic mixers fail, they can't get the same model/dimensions and it is a big issue.

I investigated the major manufacturers (because I assume they would have higher success rates and keep same models in stock) and found that their prices were absolutely crazy. I settled on this external unit and decided that if it goes bust, I can always easily replace it:

https://www.amazon.co.uk/Hausbath-Shower-Thermostat-Wall-Mounted-Thermostatic/dp/B07MT5WRQ2

This is my shower head, which will be connected to the ceiling via concealed pipes because I still want the concealed look https://www.homebase.co.uk/d-lucci-sensor-square-shower-head_p386366

I have purchased the following elbows to come out of the thermostat to go into the wall pipes: https://www.screwfix.com/p/aqualisa-shower-hose-wall-outlet-chrome-67mm/5208G

Now my question is this, will the size of the concealed pipes cause a problem with the amount of pressure the shower head gives (I can see the output hole from the thermostat is quite small)? What is the optimum pipe size I should have?

Secondly, where can I buy a 15 or 20 cm shower hose to connect the thermostat to the elbow (I want the elbow as close to the thermostat as possible, and I don't want a permanent fixture in case I need to replace the thermostat in future.

Thank you all for any suggestions/advice.

Thanks again.

 

[Madrab]

If you buy cheap then the thermostats will invariably fail sooner. That being said they should fail to cold, rather than hot. My recommendation is that your spend as much as you can on a good quality unit and make sure it is TMV2 certified.

In effect you will be using the shower outlet elbow as an inlet, connected to concealed pipework up to the rain shower head? Not sure how that's all going to look TBH.
Also the bar mixer you are linking to has 2 outlets, one to a hand held and the other to a rigid riser and depending on the direction you turn the valve sends the flow to either of the outlets.

You may have to use a SS flexible hose as I don't think you'll get a shower hose that small unless you can find a supplier that will make one up.

 

[Live&Learn]

In effect you will be using the shower outlet elbow as an inlet, connected to concealed pipework up to the rain shower head? Not sure how that's all going to look TBH.
Also the bar mixer you are linking to has 2 outlets, one to a hand held and the other to a rigid riser and depending on the direction you turn the valve sends the flow to either of the outlets.

You're right, that was my plan, and it will look ugly, but I really didn't want to spend over the odds. The cheapest decent gear I could find was the Grohe rapido smartboc and a thermostatic 3 valve control unit for £385. compared to the £65 external thermostatic unit, I figured that I'd have to have the device fail at least 5 times before I matched what the Grohe unit cost.

In any case, I could not find a shower hose at less than 30cm, and I didn't want hoses all over my new shower so I've stumped for the Grohe set.

Now my concern is this, the Grohe smart shower head is £300 and I'm not going for that right now.

1-Are there compatible shower heads (ceiling mounted)?
2-If not, would it be wise for me to connect a pipe to the third outlet concealed in the wall and cap it above the ceiling (loft is above the bathroom) in case I wanted to utilize this function in future?

Thanks all.

 

[Madrab]

Depending on the connection you could use any shower head you want. They are obviously designed to use their own but these systems are modular so you buy the unit and you can run anything off the outlets TBH.

 

[Live&Learn]

Depending on the connection you could use any shower head you want. They are obviously designed to use their own but these systems are modular so you buy the unit and you can run anything off the outlets TBH.

You are right but in the trio button controller, one of the first two buttons controls the inner holes of the shower head, the other controls the outer holes, and the third controls an external output. Is there a shower head that has a similar functionality controlled by the first two buttons?

Thanks.

 

[Gasguru]

You do realise that most of the showers on ebay/amazon etc are total junk and are illegal to install having not gone through any approvals scheme.
A known make (Bristan etc) with decent warranty doesn't cost much more and it's legit.

 

[Live&Learn]

You do realise that most of the showers on ebay/amazon etc are total junk and are illegal to install having not gone through any approvals scheme.
A known make (Bristan etc) with decent warranty doesn't cost much more and it's legit.

I did not.

I have not planned to install any showers on ebay/amazon. I have decided on grohe and would like to know if there is a compatible shower head that has the grohe functions that doesn't cost £300. I am not looking for illegal items.

Thanks