Installation manual

12 ©ESP Ltd. Sept 2008
4 . Installation 4 . Installation
4.11 DISCHARGE PIPEWORK
It is a requirement of Building Regulations that any discharge from an un-
vented system is conveyed to where it is visible, but will not cause danger to
persons in or about the building. The tundish and discharge pipes should be
fitted in accordance with the requirements and guidance notes of Building
Regulations. Building Regulation G3 Requirements and Guidance section
4.10 are reproduced in the following sections.
Information Sheet No. 33 available from the British Board of Agrément gives
further advice on discharge pipe installation. For discharge pipe arrangements
not covered by G3 Guidance or BBA Info Sheet No.33 advice should be
sought from your local Building Control Officer. Any discharge pipe con-
nected to the pressure relief devices (Expansion Valve and Temperature/ Pres-
sure Relief Valve) must be installed in a continuously downward direction
and in a frost free environment.
The water may drip from the discharge pipe of the pressure relief device and
that this pipe must be left open to the atmosphere. The pressure relief device
is to be operated regularly to remove lime deposits and to verify that it is not
blocked.
Please see figure 7 for typical discharge arrangement.
EXPANSION VESSEL
An appropriately sized expansion vessel must be fitted to the system in which
the unit is incorporated and it should discharge in to the tundish. The Expan-
sion vessel can be fitted to the cold feed in to the unit (see Figures 4 and 6).
G3 REQUIREMENT
“...there shall be precautions...to ensure that the hot water discharged from
safety devices is safely conveyed to where it is visible but will not cause dan-
ger to persons in or about the building.”
Hot water air source heat pump Hot water air source heat pump
4.9 T&P RELIEF VALVE (“TPRV”)
The TPRV is factory fitted and must not be interfered with in any way and/or
removed - under NO circumstances should the installer or end user tamper
with the TPRV or the warranty/guarantee will be invalidated and serious dam-
age may occur. You will find detailed information on this safety device at Ap-
pendix 2.
4.10 WARNINGS
i) Under no circumstances should the factory fitted TPRV be removed other
than by approved, fully trained and experienced fitters. To do so will invali-
date any warranty/guarantee or claim.
ii) The Cold Water Combination Valve, in line strainer and scale inhibiting de-
vice must be fitted to the mains water supply to the unit.
iii) No control or safety valves should be tampered with.
iv) Water may drip from the discharge pipe of the pressure relief device
(Expansion Valve) and this pipe must be left open to atmosphere. The dis-
charge pipe should not be blocked or used for any other purpose.
v) For units with primary coil facilities, please discuss use of the coil, and a
suitable configuration for use, with ESP before proceeding to add a heat
source to the primary coil.