Drain Taps; Secondary Circulation; Warnings; Secondary Circulation Connection - Ecodan 150 Standard Installation And Servicing Instructions

DRAIN TAPS

Drain taps are fitted to both the primary system pipework 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 pipework 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: A SECONDARY CIRCULATION CONNECTION AT THIS POINT MUST NOT
BE USED ON SOLAR MODELS AS IT WILL DISTURB THE DEDICATED SOLAR VOLUME OF THE CYLINDER.
The secondary return pipe should be in 15mm pipe and incorporate a check valve to prevent backflow. 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)

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.
Fig 6 - T&P Relief Valve insulation
Fig 5 - Secondary circulation connection
A
T&P RELIEF
VALVE
DISCHARGE
PIPEWORK
TUNDISH
C
PLASTIC COVER
Cold inlet
connection
RIGHT HAND
LEFT HAND
INSULATING PIECE
INSULATING PIECE
CLIP INTO
DISCHARGE PIPE
PLACE !
Cold Swept
supply tee
Secondary
return
Secondary
Check
circulation
valve
pump
B
D
17