
7
The following instructions have to be followed when install-
ing the cold water mains supply to the water heater:
- The cold water supply to the water heater must come
directly from the cold water mains after the mains
stop valve to the property.
- The cold water inlet pipework should have at least an
inside diameter of 19mm and should meet the
requirements of the water regulations for the supply
of wholesome water.
Dimplex recommend an annual maintenance inspection is
carried out on the water heater. In hard water areas this
should include inspection of the immersion heater, [above
120ppm or 120mg/l]. A local water treatment company
-
ing elements may require periodic de-scaling. The installer
should do this as part of a maintenance agreement.
Minimum dynamic pressure
Maximum inlet supply pressure
15l/min
Max. chlorine content 250mg/L
Max. water hardness 200mg/L
For satisfactory and safe performance of the water
heater the water supply must meet the following
criteria:
5.9 Cold Water Supply
of water hardness, i.e. installation of water conditioner or
water softener. These devices should be installed in hard
water areas where high water storage temperatures are re-
quired, i.e. greater than 60°C storage temperatures, par-
ticularly when water hardness exceeds 200ppm. Should the
water heater require de-scaling, this must be performed by
5.10 Building Regulation G3 Discharge
Requirements
As part of the requirements of Building Regulation G3 this
with BS EN 1490. Any discharge from a water heater system
should be conveyed to where it is visible, but will not cause
danger to persons in or about the building. The tundish and
requirements of Building Regulation approved document
G3, (England and Wales), Part P of Northern Ireland and
Standard 4.9 of Scotland.
5.10.1 Discharge Pipe D2
Dimplex strongly recommends the use of metal pipework
only and Dimplex does not take responsibility for any dam-
age caused from discharges.
The discharge pipe D2 should be at least one pipe size larg-
er than the nominal outlet size of the safety device unless
its total equivalent hydraulic resistance exceeds that of a
straight pipe 9m long, i.e. for discharge pipes between 9m
and 18m the equivalent resistance length should be at least
two sizes larger than the nominal outlet size of the safety
device; between 18m and 27m at least 3 sizes larger, and
so on; bends must be taken into account in calculating the
See Figure 3, Table 2 and the worked example.
Note: An alternative approach for sizing discharge pipes
would be to follow Annex D, section D.2 of BS 6700:2006
+ A1:2009).
Figure 2: Correct siting of Water Heater on tripod
The discharge pipe (D2) from the Tundish should:
- “have a vertical section of pipe at least 300mm long
below the tundish before any elbows or bends in the
pipework and be installed with a continuous fall of at
least 1 in 200 thereafter.”
The discharge pipe (D2) should be made of:
- “metal; or other material that has been demonstrated
to be capable of safely withstanding temperatures of
the water discharged and is clearly and permanently
marked to identify the product and performance
standard”
Figure 3: Typical discharge pipe arrangement
The heat pump water heater must be an-
chored to the wall to avoid any danger of
tipping or falling.
A tripod, makes it able to install the
heat pump water heater on the ground.
The height of the tripod is adjustable
from 300mm to 500mm. To adjust
the tripod horizontally, each foot is
equipped with an adjustment screw to
be used for this purpose.
5.8.1 On-ground Installation
5.8 Installation
Do not install the air intake nozzle near a vapour ex-
haust (minimum distance 0.6m).
*Drilling template
provided
Pre-Installation