gledhill Torrent Stainless OV, Instruction Manual

Page 10

Page 11

from any heating from the hot water pipework 

to ensure that the water remains cold and of 

drinking water quality.

A pipe thermostat is incorporated in the circuitry 

which cuts the supply to the pump when 

the water in the return pipe reaches the set 

temperature. Ensure the hot water temperature 

is set correctly to avoid excessively hot water at 

the outlets and long pump run times.

Secondary circulation pipework must be 

insulated to prevent energy loss in both heated 

and unheated areas.

Immersion Heaters

These are 3kW 230V AC heaters and incorporate 

a thermostat. The thermostat incorporates a 

manual reset.  They have incalloy elements 

to prolong their life expectancy in aggressive 

water conditions. We recommend best practice 

of connecting the wiring to the immersion heater 

is using crimp connections.

Utilising Off Peak Electricity

Where it is intended that units are fitted to 

unrestricted  offpeak circuits, then suitable 

controllers such as the Horstmann off peak electric 

time controller will be required. External wiring 

to the immersion heaters must be in accordance 

with the relevant IEE Wiring Regulations and the 

circuit must be protected by a suitable 16A MCB 

fuse and a 20A double pole isolating switch.

Safety

The immersion heaters must be earthed and they 

must be isolated from the mains before the cover 

is removed on every occasion.  Replacement 

immersion heaters should be obtained from 

Gledhill Building Products Limited.

Important

The unit must not be powered up unless the 

thermal store has been filled with water, the 

pump has been bled and water is confirmed 

to be present in the pipework above the pump.

Wiring The Control Panel

The control panel requires a separate 3 amp fuse spur double pole to ensure safe 

isolation. The cable/flex from the fuse spur to the control panel must be a minimum 

of 0.75mm

2

 C.S.A. and be heat resistant. The cable should be clipped to prevent 

accidental snagging.

The control panel front cover is secured by 4 screws. Remove these and lift off the 

front cover to expose the power terminals. These are found at the bottom left of the 

control panel. Prepare the cable end and feed it through the cable gland.

Use a screwdriver to press the neutral cross down on the WAGO connector. This opens 

the clamp and the neutral wire can be fed into the connector. Remove the screwdriver 

and test the wire is securely fit. Repeat with the PE and live cables. Tighten the cable 

gland and check for security. Perform the necessary safety checks and refit the front 

panel. 

Secondary Hot Water Circulation

If the length of the hot water draw-off pipework is excessive and the delivery time 

will be more than 60 seconds before hot water is available at the tap, you may wish to 

consider using trace heating to the hot water pipework such as the Raychem HWAT 

system. Also a conventional pumped secondary circulation system (shown below) 

can be used with any model of the Torrent Stainless.

It is important that the cold water pipework is adequately separated and protected 

Pipe Layout

In all mains pressure installations it is important to remember that the incoming cold 

supply must be shared between all terminal fittings. It is important that a 22mm supply 

is brought to the appliance and a 22mm take-off is continued at least to the bath. 

If there are two baths, 28mm pipework should be considered. One metre of smaller 

diameter pipework, or flow restrictors, should be provided on the final connection to 

all outlets so as to balance the water available. In any event the distribution pipework 

should generally be in accordance with BS EN 806:3.

Plastic Pipework

All the recommendations with regard to the heating systems in this manual are 

generally based on BS/EN Standards copper pipework and fittings. However plastic 

pipework system can be used in place of copper as long as:-

a.  The chosen system is recommended for use in domestic heating systems by the 

manufacturers and it is installed fully in accordance with their recommendations.

b.  The design criterion of the plastic system is at least equivalent to the use of BS/EN 

Standards copper pipework and fittings.

c.  Barrier pipework for these systems is recommended. 

Ball Valve and Overflow

The feed and expansion tank can be filled manually if required e.g. using a hose pipe 

fitted with a double check valve.

In this situation an overflow pipe can still be fitted if required to ensure that if a leak occurs 

on the plate heat exchanger it can be discharged safely to the outside of the building.

Note: If a ball valve is fitted, then a warning/overflow pipe must always be fitted. 

The feed and expansion tank (provided by the installer) must be sized correctly to 

enable the expansion of the entire system volume. This will include the central heating, 

store, solid fuel and boiler circuit volumes. 

See page 12 for guidance sizing the feed and expansion tank.

Water Treatment

In all Torrent Stainless models, the primary (i.e. non-potable) water is stored and the 

domestic hot water is heated instantaneously by means of heat exchangers. Therefore 

treating the primary water will not contaminate the domestic hot water supply. 

Although the Torrent Stainless primary store has no special water treatment 

requirements, the radiators and other parts of the circuit will require the application of 

a scale and corrosion inhibitor. The only Fernox products that arent compatible are the 

Flux and to a lesser extent some of our Acidic Cleaning products, namely DS40. This is 

because the Chloride in Flux can cause pitting in even Duplex Steel. The volumes and 

concentration should be calculated in accordance with the manufacturers instructions 

and when calculating the system volume (i.e. the water content), the volume of the 

Torrent Stainless should be taken into account. 

Use In Hard Water Areas And Scale Protection 

The patented design of the domestic hot water plate heat exchanger is such that 

the turbulence through the plates slows down the formation of scale in moderate 

hard water conditions. However, the requirements set out in the ‘Domestic Building 

Services Compliance Guide’ and the Building Regulations approved documents L1A 

and L1B regarding scale protection should be complied with.

INSTALLATION

INSTALLATION

INSTALLATION

INSTALLATION

Thermostat

Immersion Heater Wiring

E
L
N

These requirements state that; “where the mains 

water hardness exceeds 200ppm provision should 

be made to treat the feed water to the water 

heaters and the hot water circuit of combination 

boilers to reduce the rate of accumulation of 

scale”. To comply with this requirement: -

a.  The hardness of the mains water should be 

checked by the installer and if necessary a 

suitable in-line scale inhibitor device should 

specified for hardness levels between 200 

and 300ppm (mg/l).

b.  Where the hardness level is 300ppm (mg/l) and 

above, the optional phosphate type inhibitor 

should be specified and fitted at a suitable 

point in the cold water supply to the appliance.

It is important that where the supply to the 

Torrent Stainless is in 22mm the in-line scale 

inhibitor is also 22mm. In practice servicing is not 

normally required but in hard water areas, the 

requirements can be considered similar to those 

needed for instantaneous or ‘combi’ appliances.

The installation of scale inhibitor should be in 

accordance with the manufacturers instructions 

and Water Byelaws.

London Loop

As the thermal store gets hot the water will 

expand and the water level in the F&E tank will 

rise, as will the level of water in the vent pipe. 

Hot water will also rise to the top of the cylinder. 

When the water at the base of the cylinder 

becomes hotter it may run out the cold feed 

connection pipe. If the cold feed pipe then runs 

vertically it works like a chimney with the hot 

water rising to the top in the same way hot air 

does from a fire. If this section is not insulated 

then it will lose heat and waste energy.

If, however, the cold feed is formed into a sheppard’s 

crook or london loop it will form a thermal trap. A 

thermal trap works by ensuring that cold water is 

held below hot water. Because hot water always 

rises it will not be able to move down and around 

the loop/crook and therefore will not rise up the 

cold feed pipe work. This will reduce heat loss and 

thereby prevent energy waste.

The minimum depth of the U trap is calculated by 

multiplying the pipe diameter by 8. For example;

•  Using 22mm pipework will require a 

minimum of 176mm

22mm pipework is highly recommended to 

ensure that the London loop does not air lock 

during the commissioning process. It also 

enables a faster installation of the product due 

to the increased filling rate.

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J18 

J20 

J19 

J3 

J7 

J8 

J1 

TS sensor 

GND    GND 

 IN         OUT 

T1            T2  

1 

2 

CW sensor 

1 

2 

Combined flow  

and  

HW temperature  

sensor 

L - Brown 

PR61 

E – G/Y 

N - Blue 

PW

M 

- 

PW

M 

+ 

SP

ARE

Fuse 

Dip

Sw

itc

h 

1 2 3 4

To  

DHW  

pipe 

All the these sensor inputs carry a 

Voltage of 5V.  

The max cable length is 1 meter.  

The sensors connected to the control 

Should be free from the appliance earth 

Torrent Stainless

Inline filter &

flow regulator

Single check

valve

Single

check

valve

Pump isolation

valves

Cold water inlet

Plate heat exchanger

Hot water outlets

Pipework length and

diameter to suit

property demands

Pipework length and

diameter to suit

recirculation flow rate

approx 1-2 l/min

Cold water sensor

Control

stat

Flow sensor

Potable water

expansion vessel

Secondary

circulation

pump