Water Quality And System Preparation; General; New Installation; Existing Installation - Mitsubishi Electric EHST20-Serie Installationshandbuch

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installation

4.2 Water Quality and System Preparation

General

• Water quality should be to European Directive 98/83 EC standards.
► pH value of 6.5-8.0 (Recommended: pH6.5 - 7.5)
► Calcium ≤ 100 mg/l
► Chlorine ≤ 100 mg/l
► Iron/Manganese ≤ 0.5 mg/l
• In known hard water areas, to prevent/minimise scaling, it is beneficial to restrict
the routine stored water temperature (DHW max. temp.) to 55°C.

new installation

• Before connecting outdoor unit, thoroughly cleanse pipe work of building debris,
solder etc using a suitable chemical cleansing agent.
• Flush the system to remove chemical cleanser.
• For all packaged systems add a combined inhibitor and anti-freeze solution to
prevent damage to the pipe work and system components.
• For split systems the responsible installer should decide if anti-freeze solution is
necessary for each site's conditions. Corrosion inhibitor however should always
be used.

How to access internal Components and Control Box

<A> Opening the front panel
. Remove the two lower screws.
2. Slide front panel upwards to open.
3. disconnect main controller cable from quick release connector.
<B> Opening the control box cover
. Remove the four screws.
2. Remove the control box cover.
<C> Accessing the back of the control box
The control box is hinged on the left hand side and has two holding screws on the right.
. Remove the two holding screws on the control box.
2. The control box can then be swung forward on the left hand hinges.
Note:
. Before accessing back of control box release cables from cable straps and
bendable clamp to avoid damage.
2. After servicing re-secure all cables using straps provided and reconnect main
controller cable to quick release connector.
<Before water pipe work>
When installing the cylinder unit, be sure to remove polystyrene cushion that is
attached to the booster heater, as shown in the figure below.
When removing the cushion do not touch the pipes.
After removing the cushion peel off the notice label that is stuck on the booster
heater.

4.3 Water Pipe work

Hot Water Pipe work

the cylinder unit is UnVented. When installing unvented hot water sys-
tems building regulations part G3 (England and Wales), P3 (Scotland) and P5
(Northern Ireland) should be adhered to. If outside of the UK please adhere
to your own country's regulations for unvented hot water systems.
Connect the flow for the DHW to pipe A (Component diagrams).
The function of the following safety components of the cylinder should be
checked on installation for any abnormalities;
• Pressure relief valve
• Temperature and pressure relief valve (EHPT20X-VM2HA ONLY)
• Expansion vessel pre-charge
The instruction on the following pages regarding safe discharge of hot water from
Safety devices should be followed carefully.
• The pipe work will become very hot, so should be insulated to prevent burns.
• When connecting pipe work, ensure that no foreign objects such as debris or
the like do not enter the pipe
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existing installation

• Before connecting outdoor unit the existing heating circuit MUST be chemically
cleansed to remove existing debris from the heating circuit.
• Flush the system to remove chemical cleanser.
• For all packaged systems add a combined inhibitor and anti-freeze solution to
prevent damage to the pipe work and system components.
• For split systems the responsible installer should decide if anti-freeze solution is
necessary for each site's conditions. Corrosion inhibitor however should always
be used.
When using chemical cleansers and inhibitors always follow manufacturer's
instructions and ensure the product is appropriate for the materials used in
the water circuit
<A>
Front
panel
Screws
<Figure 4.2.>
Pump
<Figure 4.2.2>

Cold Water Pipe work

Cold water of a suitable standard (see section 4.2) should be introduced to the
system by connecting pipe B (Fig 3.1) using appropriate fittings.

Hydraulic filter work (ONLY EHPT series)

Install a hydraulic filter or strainer (field supply) at the water intake ("Pipe G" in
Fig.3.3, Fig.3.4)
<B> <C>
Hinges
Screws
Tank
CUSHION
Booster heater
Screws
Open
Notice
label