Ecodan EHPT17X-UKHLEWS Installation Manual page 4

INTRODUCTION
This range of factory pre-plumbed and wired unvented water heaters are specifically designed for use with the Ecodan
PUZ-WZ & PUZ-(H)WM Air Source Heat Pump ranges. The cylinder is manufactured in the UK from top quality materials
and meets all the latest relevant safety and constructional standards. The high grade Duplex stainless steel cylinder offers
exceptional strength and corrosion resistance. Its performance, control system and insulation levels exceed the latest
requirements of Building Regulation Part L.
The unvented water heater can be fed directly from the cold water mains supply to the property without the need for
separate feed cisterns or vent pipes. This is a fixed installtion therefore flexible hoses MUST NOT be used to connect
to the mains. It is supplied fitted with all its necessary inlet and safety controls for compliance with Building Regulations.
Also fitted are heat pump circulating pump, heating zone 1 circulating pump, DHW circulating pump, primary to DHW
plate to plate heat exchanger, 3-way diverter valve, cyclonic filter, scale trap, heat pump flow and return thermistors, two
cylinder thermistors, primary circuit drain off valve, DHW circuit drain off valve, DHW secondary return tapping (210 L+
only), low loss header, flow sensor, automatic air vent, primary filling loop and pressure gauge, a cylinder thermal cut-out,
Wi-Fi adaptor and FTC7 controller. The pumps, motorised valve and thermal controls are supplied pre-wired. The DHW
expansion vessel is supplied loose for installation at a convenient position within the property. An electric immersion heater
is also fitted to enable the unit to be heated should the heat pump require supplementary heating or be turned off.
NOTE: When using a sealed heating system, adequate provision for expansion within the primary circuit MUST be
provided by fitting a primary circuit expansion vessel. Primary circuit expansion cannot be accommodated within the Air
Source Heat Pump cylinder. A primary circuit pressure relief valve is fitted within the Ecodan PUZ-WZ & PUZ-(H)WM air
source heat pump outdoor units.
The safety valves fitted to the Air Source Heat Pump cylinder protect the water heater only. Failure to provide adequate
primary system pressure relief when using a sealed heating system will invalidate the Heat Pump warranty. Consult the
Heat Pump installation instructions for further advice.
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