Our customer had a newly refurbished Victorian terraced house in a rather upmarket area of Wandsworth, SE London.
Their newly configured bathrooms were let down by the shower pumps. Noisy, vibrationary and liable to intermittently start in the middle of the night.
Because the property had been extended into the loft, one of the shower pumps was a ‘negative pressure’ type. These have to push water out of the tanks uphill, because in most loft extensions there is insufficient space or load bearing ability to site water tanks above shower rose level. The negative head pump incorporates a set of bellows and detects a small change in air pressure in the pipe when you turn the shower on; it starts pumping straight away!
Unfortunately, just a small air leakage over time in the pipe also makes the shower pump believe you have opened the tap – so they are prone to randomly starting. When this happens in the middle of your sleep you start considering the alternatives.
We removed the old water tanks and the old copper hot water cylinder and converted the system over to a modern Vaillant uniSTOR 260 pressurised (unvented) cylinder.
Vaillant uniSTOR and controls installed by HWCH in Wandsworth Oct 2008
The uniSTOR is a modern unit of very neat appearance and is our ‘weapon of choice’ for unvented cylinders.
The showers in the property now work at mains pressure, quietly.
And our customer has two nearly new pumps to sell on Ebay.
All unvented cylinders require an emergency water discharge, which is normally copper. On this installation we used plastic waste pipe, which has been tested by the Building Research Establishment (BRE) and certified for use with a special adaptor trap; this makes our options for the siting of unvented cylinders more flexible.
