Grohtherm Wireless feeds and location All aspects of plumbing questions and answers, help, tips and information

[rormerod]

Hi

I'm looking to fit a Grohtherm Wireless Thermostatic Shower - the pumped version as we have gravity fed system with CWS tanks in loft and hot water cylinder in a cupboard in room adjacent to an ensuite bathroom.

Is there a need to have dedicated pipework to this unit? e.g. direct from hot water tank (Grohe instructions are not clear) or would it be possible to use existing pipework? Reason I ask is that there is 15mm pipework to a bidet which we are removing with the cold being from the CWS rather than mains. This would be easiest option as pipework is almost in the perfect place :D Also, plan is to place the Grotherm unit in a floor level cupboard in ensuite - Grohe say under bath is ok so presume this is too?

If anyone has this unit or has fitted one and can help that would be much appreciated. Thanks.

PS: Am aware of Part P and will be getting professionals in to do the work!

[plumbbob]

It depends on what you mean by existing pipes. Generally all low pressure showers whether pumped or not need dedicated feeds from both the header tanks and DHW cylinder. It may be possible for it to work if the supply is tapped off close to the cylinder output, but for best results, it is better to fit a Surrey or Ess-ex flange.

You can use the redundant bidet cold supply providing the pipework is full bore, but the hot must come directly from the cylinder tap off point otherwise air may be drawn into the system.

It is better to place the pump in the airing cupboard and pump the water to the shower rather than under the bath and suck it. Easier access for maintenance too.

[rormerod]

Thanks for taking the time to reply - all points make good sense of course.