Ecodan EHPT15X-UKHDW1S, Installation Manual

Page: 19 / 52

19
DRAIN TAPS
Drain taps are fitted to both the primary system pipe work and to the cold water inlet to facilitate draining the unit or indirect
heating circuit for maintenance purposes. It is recommended that the outlet point of the drain pipe work be at least 1 metre
below the level of the heater (this can be achieved by attaching a hose pipe to the drain tap outlet spigot).
HOT WATER OUTLET
Ideally the pipe work from the cylinder to the outlet fittings should be in 22mm pipe with short runs of 15mm pipe to showers
and basin taps. Small bore pipe can also be used to suit some taps, but runs should be of minimum length. Pipe sizes may
vary due to system design.
SECONDARY CIRCULATION
If secondary circulation is required it is recommended that it be connected to the cylinder as shown in Fig. 5 below via a swept
tee joint into the cold feed to the unit. Note: 210L, 250L & 300L Standard models only have a secondary return tapping.
The secondary return pipe should be in 15mm pipe and incorporate a check valve to prevent back flow. A suitable WRAS
approved bronze circulation pump will be required. On large systems, due to the increase in system water content, it may be
necessary to fit an additional expansion vessel to the secondary circuit. This should be done if the capacity of the secondary
circuit exceeds 10 litres.
Pipe capacity (copper):
15mm O.D. = 0.13 l/m (10 litres = 77m)
22mm O.D. = 0.38 l/m (10 litres = 26m)
28mm O.D. = 0.55 l/m (10 litres = 18m)
Fig. 5 - Secondary circulation connection
A
B
C D
T&P RELIEF
VALVE
DISCHARGE
PIPEWORK
TO TUNDISH
LEFT HAND
INSULATING
PIECE
PLASTIC COVER
CLIP COVER INTO
PLACE
RIGHT HAND
INSULATING
PIECE
Fig. 6 - T&P Relief Valve insulation
WARNINGS
i) Under no circumstances should the factory fitted temperature/pressure relief valve be removed other than by authorised
service personnel. To do so will invalidate any guarantee or claim.
ii) The cold water combination valve must be fitted to the mains water supply to the unit.
iii) No control or safety valves should be tampered with.
iv) The discharge pipe should not be blocked or used for any other purpose.
v) No other valves should be placed between the expansion relief valve and the cylinder.
Cold inlet
connection
Check
valve
Secondary
circulation
pump
Swept
tee
Cold
supply
Secondary
return
INSULATION OF PIPEWORK
i) All exposed water pipework should be insulated to
prevent unnecessary heat loss and condensation.
ii) Cold and hot water pipework should not be run close
together where possible, to avoid unwanted heat
transfer.
iii) Pipework between outdoor heat pump unit and cylinder
unit should be insulated with suitable pipe insulation
material with a thermal conductivity of ≤ 0.04 W/mK.