Trevi Outline, Therm, Traditional Installation Instructions Manual
Installation Instructions
A3000 Trevi Therm built-in thermostatic mixer
A3700 Trevi Outline built-in thermostatic mixer
E3115 Trevi Traditional built-in thermostatic mixer
INSTALLER:
After installation please pass this instruction booklet to user
TREVI SHOWERS
Trevi Outline
Trevi Traditional Trevi Therm
trevi showers.qxd 04/12/03 13:21 Page 1
WATER REGULATIONS
Hot and cold water supply pressures must be
reasonably balanced and from a common
source - both from storage or both from a
supply pipe. (IRN 101). The mixers will function
within specification on unequal pressures up to
a ratio of 5 : 1, but it is not recommended that
the cold supply be connected to the rising main
and hot to the tank fed supply as the pressure
differential is likely to exceed the 5:1 ratio.
The minimum pressure for correct operation is
0.1 bar (1m head - see Figure 5). Pressure head
is measured as the vertical distance between the
bottom of the cold water storage tank which
feeds the hot water system and the highest
point on the shower spray plate.
When installing with a shower pump the use of
a secondary tapping from the cylinder is highly
recommended.
Figure 1 shows the various methods of connecting
the hot water pipe to the cylinder - the most
preferred on the left and the least preferred on
the right.
The fitting should be so installed as to be readily
accessible for examination, repair, replacement or
operation. (IRN 111).
The temperature of the hot water must not exceed
85ºC but the installer’s attention is drawn to code
of practice BS 6700 which recommends that
stored hot water should normally never exceed
65ºC. For correct operation of the valve, a
minimum of 52ºC is required.
GENERAL NOTES
Trevi thermostatic shower mixers are designed to be installed on normal UK low
pressure storage tank fed systems, unvented high pressure systems, modulating
instantaneous water heaters or modulating combination (combi) boilers. They are suitable
for all pumped applications.
Figure 1 Preferred locations of cylinder tapping
1
FOR HEALTHCARE ESTABLISHMENTS
In accordance to NHS model engineering specification DO8 the valve has approval for the following
applications: High pressure -HP-S
Low pressure -LP-S
TMV3 approval number: ETC/227/0903
trevi showers.qxd 04/12/03 13:21 Page 2
When installing on a modulating combination
boiler it is sometimes possible for the interaction of a thermostatic valve with the combi to
cause the boiler to cut out and cut in again with
the result that the water will become alternatively cold and hot. To overcome this, flow
restrictors should be fitted upstream of the
thermostatic valve.
The Do8 approval of this fitting only
applies when installed without the flow
restrictors.
Trevi supply in-line strainers/servicing valves (28)
which include these flow restrictors. These
should be inserted in the downstream side of
the servicing valve as shown on Figure 2. It is
essential that they are positioned the right way
round as shown in the sketch. Remove the compression nut and olive from the outlet side of
the Isolating valve and place the restrictor in the
outlet. Push to the bottom of the recess. Fit Oring in the visible rebate around the edge of the
restrictor and push home until it is fully in the
rebate. Use the tip of a small screwdriver or similar to achieve this.
Servicing valves should be fitted as close as is
practical to the shower valve.
CATEGORIES OF RISK
The water regulations published in 1999* take a
new approach to backflow in that they look at
different categories of risk. The installer must
assess the risk from the various categories of
fluid in adjacent appliances before determining
the level of backflow protection required for a
particular installation. Figures 3 & 4 describe the
protection required in various installations.
CATEGORY 3 RISK
Water in a shower tray, basin or bathtub is
considered to be a fluid category 3 risk which is
a fluid which represents a slight health hazard if
it were to find it’s way back into the supply pipe.
For this reason it must not be possible for any
flexible shower head to be able to enter any adjacent washbasin, bath or shower tray unless
appropriate protection is employed. (See Figure 3).
Figure 2 in-line filter and service valve
showing restrictor
*A guide to the Water Supply (Water fittings) Regulations 1999 and the Water Byelaws 2000, Scotland is
published by WRAS (Water Regulations Advisory Scheme) Fern Close, Pen-y-Fan Industrial Estate, Oakdale, Newport, NP11 3EH.
ISBN 0-9539708-0-9.
WATER REGULATIONS 2
Table 1 Conditions for normal use
Operating pressure range: High Pressure Low Pressure
Maximum static pressure - Bar 10 10
Flow pressure hot and cold - Bar 1 to 5 0.2 to 1
Hot supply temperature - °C 52 to 65 52 to 65
Cold supply temperature - °C 5 to 20 5 to 20
Temperature differential characteristic (TDC) °C 10 10
Valves operating outside of these conditions cannot guaranteed to perform as type 3.
Approval only applies when the valves are installed without the flow restrictors
illustrated in Figure 2.
trevi showers.qxd 04/12/03 13:21 Page 3
If it is desired to allow the hand spray
to be used inside say a bathtub or a
basin it is essential that double check
valves be fitted to the inlet on both
hot and cold supplies to the thermostatic valve. Alternatively single check
valves can be fitted at the inlets and
an additional check valve should be
fitted in the valve outlet.
No check valves need be fitted if
the hand spray is prevented from
reaching closer than 25mm of the
spill over level of any such fixture.
CATEGORY 5 RISK
Water in a Sink, WC or Bidet is
considered to be a fluid category 5
risk which is a fluid which represents
a serious health hazard if it were to
find it’s way back into the supply
pipe. For this reason it must not be
possible for any flexible shower head
to be able to enter any adjacent Sink,
WC or Bidet. If the flexible hose to be
fitted could reach into any such
vessel, the requirements to the
system design are so onerous it is
better not to fit a flexible. Rather, a
fixed overhead showerhead should
be considered. (See Figure 4).
It will also be seen that this risk could
change should the hose be taken out
of the restraining device or should a
longer replacement hose be fitted at
a later date. Installers and householders are advised to take account
of these factors when fitting replacement hoses.
For pumped applications the pipe
supplying the pump must not in
addition supply an ascending spray
bidet.
Figure 3 Illustration of backflow risk from fluid
Category 3 risk
WATER REGULATIONS3
Figure 4 Illustration of backflow risk from fluid
Category 5 risk
trevi showers.qxd 04/12/03 13:21 Page 4
GRAVITY/PUMPED SYSTEMS
Figure 5 Recommended system layout for gravity applications
Figure 6 Recommended pumped system layout
GRAVITY & PUMPED SYSTEMS 4
trevi showers.qxd 04/12/03 13:21 Page 5
Loading...