Advice on Grohe Grohtherm Wireless

[wetbehindtheears]

Hi, we've got an ensuite bathroom which used to have a nice shower until the pump froze earlier in the year which did for the seals, cracked the casing and led to water cascading through our property for just over a week (we were away).
Insurance covered the majority of the damage though not the cause of the escape of water - the pump itself - so we've left sorting that until last!
Anyway enought of the woes! What I was after was advice on replacement - I'd like to have a rough idea of what I'm talking about before getting people in to do quotes etc.

Our house has gravity fed system with 2 x 36 gallon cold tanks in the loft and a large 28 gallon hot water cylinder (over night Econ7). These fed a Stu Turner 4.0 bar twin imp pump. Looking at website you could pump a small village with that thing - but I think reason it was 4.0 bar was prev. owners had 1 overhead and 4 bodyjets (a lovely bespoke job ). The ST pump was actually some distance from hot/cold tanks, was overhead the ensuite in loft and fed by 22mm piping.

I've been looking at the Grohe Grohtherm Wireless options - elsewhere on forums there are favourable comments regarding these.

I'm assuming I'll need pumped thermostatic version here (given gravity fed/loft tank system) - pressure needs to be between 0.1-1.0bar?
http://www.grohe.co.uk/m/25_982/pag...?part=view&action=view&article=36022&offset=0

Other questions i had were:
Any advice on siting these - the Stu Turners were meant to be as close to hot water as possible (though ours wasn't). However, the Grohe ones don't mention this?
Loft would be ideal but am slightly nervous after previous experience! Can these be 'boxed' in with insulation surrounding (though obviously not touching) or will this cause overheat?
Will same pipework be ok - i.e. 22mm reduced down to 15mm for inlet to the Grohe?
Is there any chance input pressure will be greater than 1.0bar? If in loft it will be above top of hot water cylinder and at about same level as bottom third of the cold water tank. There is a high pressure variety but I really don't think this is appropriate for gravity fed?

Any views/advice much appreciated!

PS: We now turn the water off when going away...

 

[ChrisR]

SO are you using a pump or not?? You're talking about pumps, and gravity fed ???????

O.1 bar is ONE meter head so with the
18l/min at 0.1 bar
they quote you hardly need one, though it will feel like water is only falling on you and not being squirted.

28 gallon hot water cylinder

Not big if your shower's 18l/min mixed H & C.
About 10 mins of showering, if it stores 28 x 4.54 = 120l.

 

[wetbehindtheears]

Thanks for the reply. We have gravity fed for the house but the original shower was powered by the Stuart Turner pump to provide a decent shower.
What I'm debating is whether I just replace the Stuart Turner pump with a similar model or whether I can install the Grohe Geotherm digital instead of a more traditional twin impeller pump and get a decent shower out of it - the Grohe is meant to be pumped?.

Am i right though that a gravity fed system with no pump will produce between 0.1 and 1.0bar for both hot and cws tanks from loft?

Thanks,

PS: I got the hot water cylinder wrong - its 40Gal but get your point about flow etc.[/b]