Potthof & Co 28kw, 24kw, 33kw manual Domestic Hot Water Circuit Fig, Showers, Hard Water Areas

Other Tap

Outlets

Expansion	Boiler
Vessel*

Check

Valve*

6.0System Details

6.8Domestic Hot Water Circuit (Fig. 7)

1.All DHW circuits, connections, fittings, etc. should be fully in accordance with relevant standards and water supply regulations.

2.Your attention is drawn to:

for GB: Guidance G17 to G24 and recommendation R17 to R24 of the Water Regulations Guide.

for IE: the current edition of I.S. 813 “Domestic Gas Installations”.

3. The Water Regulations recommendations for England and

Wales prohibits backflow from appliances into the

wholesome water supply due to thermal expansion.

However this type of instantaneous combination boiler, with

less than 15 litres of stored capacity, does not require any

Pressure Reducer Valve*

Stop Tap

To Hot

Taps

*See 6.8 for instances when these items may be required

backflow prevention device as any thermal expansion is

accommodated within the appliance.

It is possible in certain circumstances that other cold water

demands (e.g. washing machines, flushing of W.C.s) may

affect the DHW function of the boiler. In these instances the

fitting of a backflow prevention device and expansion vessel

is recommended.

4. Also if there is an existing check valve, loose jumpered

Fig. 7

stop cock, water meter or water treatment device already
fitted to the wholesome water supply connected to the
boiler domestic hot water (DHW) inlet supply then a
suitable expansion device may be required.
5. The boiler’s maximum working mains pressure is 8 bar,
therefore all pipework, connections, fittings, etc. should be
suitable for pressures in excess of 8 bar. A pressure reducing
valve must be fitted for pressures in excess of 8 bar. The
manufacturer of any outlet fittings, such as a shower valve,
may require a lower maximum pressure. The pressure
reduction must take account of all fittings connected to the
DHW system.
6.9	Showers

1.If a shower control is supplied from the appliance it should be of the thermostatic or pressure balanced type. Thermostatic type shower valves provide the best comfort and guard against water at too high a temperature. Existing controls may not be suitable - refer to the shower valve manufacturer.

6.10Hard Water Areas

1.If the area of the installation is recognised as a HARD WATER AREA then a suitable device should be fitted to treat the mains water supply to the boiler. Contact your Water Distribution Company for advice on suitable devices.

14© Baxi Heating UK Ltd 2012