McDonald Engineers POWER flow 2000 Series User manual

UNVENTED HOT WATER SYSTEM
McDONALD ENGINEERS
HOT WATER SYSTEMS
FLEMINGTON ROAD, QUEENSWAY INDUSTRIAL ESTATE, GLENROTHES FIFE KY7 5QF
Tel : [phone] Fax : [phone]
Email : [email protected] Internet : www.mcdonald-engineers.com
INSTRUCTIONS
PLEASE LEAVE WITH HOUSEHOLDER
IMPORTANT - Failure to install and maintain this system in
accordance with these instructions will invalidate the
manufacturer’s warranty.

1
IMPORTANT
Installation should only be carried out by a
‘competent operative’ i.e. the installer must
have attended a recognised course in
Unvented Hot Water Systems or received
appropriate training in their apprenticeship.
All registered operatives should carry an
Identification Card issued by the Institute of
Unvented Hot Water Systems or SNIPEF
(Scottish and Northern Ireland Plumbing
Employers’ Federation), the Construction
Industry Training Board or the Institute of
Plumbers.
The unit should be
handled with care in order to avoid
damage to valves. It should be stored
upright in its box in a dry place.
Full weights are available at the back of
this booklet. The installation area should
be able to cope with this weight, incoming
pipes and discharge pipe. Position the
unit to suit the installation.
All connections are to the front to enable
ease of access. Ensure suitable space is
left for access for repair and/or
replacement of valves etc.
In areas with hard water we would
recommend restricting the temperature
and performing de-scaling procedures as
required.
All the following instructions must be
carried out: -
1. Installers should ensure incoming
mains pressure is less than 12Bar and
that local authority approval for
installation of Unvented Systems is
granted. Ensure adequate flowrate is
available.
2. Excessive use of flux can damage the
unit and especially the valves and
expansion vessel. Avoid over-use and
ensure the system is fully flushed of
any debris or flux before connection.
3. Incoming mains to arrive in a
minimum of 22mm copper pipe which
is to be fitted to the Pressure
Reducing Valve Set at 2.1 Bar (A - see
Page 4) which includes a serviceable
Strainer. We would strongly
recommend this valve is fitted where
the mains enters the property, but it
can go wherever is most suitable for
the installation, between the mains
stopcock and the cylinder.
We recommend fitting a Tee between
the Pressure Reducing Valve (A) and
the Check Valve (A2) to provide a
BALANCED COLD OUTLET for all
cold taps, preventing cross-flow and
also giving potable water throughout
the house. Outdoor taps for hoses
should be taken before the Pressure
Reducing Valve.
4. The Check Valve (A2) is factory fitted
at the Cold Feed (C). No isolating
valve may be fitted between the check
valve and the storage cylinder.
5. The Temperature & Pressure Relief
Valve (D) set at 90°c and 4.5 Bar, and
the Expansion Relief Valve (B) set at
3.5 Bar, are factory fitted and
connected to the Tundish (E). NB -
the relief valves are only to be used
for relief discharge purposes.
No valves should be fitted between
the relief valves and the cylinder.

2
6. The Tundish (E), which shows visible
discharge from the Relief Valves, is to
be in a prominent, visible and safe
position away from any electrical
devices (likewise with the drain
connection) and within 500mm of the
Temperature & Pressure Relief Valve
(D). Pipework from the Tundish (E)
must initially be vertical for a minimum
of 300mm where possible and then
have a continuous fall in excess of 1
in 200. Pipework away from the
Tundish (E) should be in a minimum of
22mm, of material suitable for
temperatures of 95°C and have a
resistance to flow of water not greater
than that of a straight pipe of 9 metres
(each bend or elbow is equal to 0.8
metre of resistance). See BBA
Information. Sheet No 33:1989 for
further details - available from the
manufacturer. Also note page 9 of
these instructions.
7. The Expansion Vessel (F) charged at
2.1 Bar, should either be fitted directly
to connection (M) on the cylinder, or if
space dictates, securely to the wall
with the optional remote fixing kit and
the hose fitted between the vessel and
connection (M).
8. Connect the 3kW 11” 240V Immersion
Heater/s BSEN 60335/2/73 (with
manual re-set cut out at 80°C) to the
power supply and earth them in
accordance with the current IEE wiring
regulations. The fuse rating should be
13 Amps. Do not at any time fit
Immersion Heaters without a thermal
cut-out.
9. On Indirect Units where a Coil is fitted
to the cylinder, the supplied Two Port
Motorised Zone Valve and Dual
Thermostat Controller (J) must be
fitted in accordance with the
instruction details supplied with them
for the appropriate installation.
N.B. Indirects, are suitable for oil,
gas and electric fired boilers on a
pumped, gravity or sealed system.
(We would however recommend
28mm Coil connections with a 28mm
Zone Valve on gravity systems).
Maximum working pressure of the
coil is 3.5 Bar. All electrical wiring to
thermostats, zone valve and
immersion heaters must be earthed
and to current IEE Wiring Regulations.
The fuse should generally be 3 Amps
but refer to appliance instructions to
confirm this.
10. The SecondaryReturn (L) if supplied,
should be plugged if not required. If
the Secondary System pipe-work is
greater than 15% of the unit capacity,
alarger Expansion Vessel may need
to be fitted - contact McDonald
Engineers.
11. Immersion Heaters (H) and the Dual
Aquastat Controller (J) supplied with
the Indirect units should be set to no
greater than 60°C and the internal
High Limit Thermostats are factory set
no higher than 85°C. Always check
this before switching on power.
Please see the checklist on page 4
to ensure all controls are present
and correct.

3
ONCE ALL THE PRECEDING INSTRUCTIONS HAVE BEEN
FOLLOWED, COMMISSION THE SYSTEM.
IMPORTANT
COMMISSIONING - These instructions
must be followed.
After following the instructions on pages
1&2proceed as follows: -
1. Close the Drain-cock (I) at base of
cylinder.
2. Open a Hot Tap.
3. Fully open the Cold Mains Stopcock
and fill Cylinder until water appears at
the Hot Tap.
4. Close the Hot Tap and attend each hot
water outlet in turn and ensure water
flow is obtained at each.
ENSURE THAT ALL FITTINGS AND
PIPEWORK ARE WATERTIGHT.
All factory fitted valves etc. are fitted
using a thread sealant.
If this seal is broken it should be
re-sealed using a suitable sealant.
5. Check the control thermostats on the
Immersion Heater/s (H) and the Dual
Thermostat (J) are set no higher than
60°C and that the High Limit
Thermostats are set to no higher than
85°C.
6. Ensure there is no discharge from the
Relief Valves (B and D).
7. Switch on water heating system and
check operation of the system.
IT IS EXTREMELY IMPORTANT TO
FOLLOW ALL THE INSTRUCTIONS
PREVIOUSLY MENTIONED, AS FAILURE
TO DO SO COULD BE DANGEROUS OR
LEAD TO THE SYSTEM WORKING
INEFFICIENTLY.

4
A - Pressure Reducing Valve with Strainer.
A2 - Check Valve.
B - Expansion Relief Valve.
C - Cold Feed.
D - Pressure & Temperature Relief Valve.
E - Tundish.
F - Expansion Vessel.
G - Hot Water Draw Off.
H - Immersion Heater 80°C cut-out.
I - 15mm Drain-cock.
J - Dual Thermostat Controller.*
K - 22mm Connections to Primary Coil.
The supplied Zone Valve must be fitted
and also a High Limit Stat fitted to the
Boiler.* For Solar coils see back page.
L - 22mm Secondary Return. Plug if not
required (only on 180 litre units &
bigger).
M - 22mm Boss for Expansion Vessel.
*Indirects only
CHECKLIST
A
GM
F
B
D
E
K*
I
A2
C
H
J*
H
L
Optional on Indirects
Std. on 150 Direct Upwards
Solar Units only
See back page

5
ANNUAL MAINTENANCE
should be serviced at
least once a year by a competent
operative.
IMPORTANT - failure to maintain this
system in accordance with these
instructions will invalidate the
manufacturer’s warranty. A maintenance
record should be kept on the ANNUAL
SERVICE RECORD card provided on
page 10, we would recommend a service
program is arranged on installation.
Failure to maintain this record will
invalidate the manufacturer’s warranty.
Contact McDonald Engineers to arrange
the appropriate service program.
ANNUAL SERVICE CHECKS
Expansion Relief Valve (B) -manually
open the twist cap and check that the
water is discharged and runs clearly
through the Tundish (E) and out at the
final discharge point. Ensure that the
valve re-seat/re-seals itself.
Pressure & Temperature Relief Valve (D) -
repeat the above procedure. Ensure that
the valve re-seat/re-seals itself.
Strainer (A) -turn off mains at stopcock.
There will be a small amount of residual
water in the pipework, remove the
cartridge from Pressure Reducing Valve
(A), clean Strainer and replace.
Expansion Vessel (F) -Check Pressure
via the valve on top of the vessel which is
located under the plastic cap. Ensure
pressure is 2.1 Bar. Vessel can be re-
charged if required as per “Recharging
Expansion Vessel” on page 6 opposite.
PROBLEM SOLVING
DISCHARGE FROM EITHER OF THE
RELIEF VALVES INDICATES A
MALFUNCTION IN THE SYSTEM AND
MUST BE INVESTIGATED IMMEDIATELY.
OVERHEATED HOT WATER
DISCHARGE
In the unlikely event of overheated (90°C)
water being discharged, the heat source
i.e. the immersion heaters or the central
heating boiler should be switched off
immediately and a competent operative
called out. Ensure that the discharge of
hot water or steam at the Tundish (E) or
final discharge point causes no danger
and is not likely to injure anyone.
DO NOT SHUT OFF THE COLD WATER
SUPPLY TO THE UNIT!!
DO NOT RE-USE UNTIL CHECKED AND
REPAIRED!!
ENSURE COMPONENTS ARE ISOLATED
FROM ELECTRICITY BEFORE
INVESTIGATION!!
Once cold water has entered the unit and
displaced the over heated water thus
cooling it, check the thermostat and
energy cut out in the a) Immersion Heater,
b) Thermostat, c) Boiler. Identify the
faulty component and replace with the
correct component as supplied by the
manufacturer and ensure that it works
before re-commissioning the system.
DO NOT FOR ANY REASON BY-PASS AN
ENERGYCUT-OUT.
Problem Solving continued on page 6...

6
WATER DISCHARGE
If water is occasionally being discharged
as the water is heated, this would be
likely to indicate that the Expansion
Vessel (F) needs recharged. In the event
of it occurring, switch off all power
supplies to the cylinder, re-charge the
vessel as below.
If water is continually being discharged,
firstly check with a gauge that the
pressure allowed through the Pressure
Reducing Valve (A) does not exceed 2.1
Bar. If it does exceed 2.1 Bar the
Pressure Reducing Valve should be
replaced using a replacement supplied by
McDonald Engineers. Next, check the
charge in the expansion vessel and
recharge as below. If the pressure is okay,
check which valve is discharging and
replace with a replacement supplied by
McDonald Engineers.
RECHARGING
EXPANSION VESSEL
To recharge the expansion vessel, close
the mains stopcock and open a hot tap.
Connect a pump with gauge to the air
inlet on top of the vessel and charge to
2.1 Bar (30 PSI).
HOW TO DRAIN SYSTEM
Switch off water at mains and open a hot
tap. Connect the Drain-cock (I) to a hose
and open, the cylinder will now start
draining through the hose.
T
o re-fill follow the commissioning
instructions on Page 3.
N.B. Toflush out the system, drain the
unit as above, fill and repeat.
IF PROBLEMS CONTINUE
If after recharging the expansion vessel
the cylinder is still discharging, it may be
cross-flow - ensure appropriate check
valves are fitted. The Pressure Reducing
Valve (A), one of the Relief Valves (B or D),
(as previously mentioned) or the
Expansion Vessel (F) has failed. The
component should only be replaced by a
replacement part supplied by McDonald
Engineers. Contact McDonald Engineers
for further information.
IMMERSION HEATER
FAILURE
If the Immersion Heater (H) is not heating
the water it has either failed (In which
case a replacement Immersion Heater as
supplied by McDonald Engineers should
be fitted) or the electrical cut-out has
operated due to the control thermostat
being set too high or being faulty.
On Indirect units it may be a faulty stat in
the boiler is allowing the water to
overheat and operating the Immersion
cut-out.
(CHECK THE IMMERSION HEATER IS
ISOLATED FROM THE MAINS)
Once these have been checked and/or
replaced, the Immersion Heater can be
re-set by taking off the cap and
depressing the button in the Immersion
Heater on the High Limit Stat
Should any fault or problem arise not
covered in this leaflet, please contact
the manufacturer.

7
TECHNICAL DATA
Weights Direct Indirect
Empty (kgs) Full Empty (kgs) Full
75 Litre POWERflow 2000 24 99 26 101
120 Litre POWERflow 2000 33 153 37 157
150 Litre POWERflow 2000 39 189 44 194
180 Litre POWERflow 2000 49 229 55 235
210 Litre POWERflow 2000 55 265 61 271
300 Litre POWERflow 2000 80 380 86 386
Heat Up Times 10-60°C Direct Indirect
75 Litre POWERflow 2000 89 mins 21 mins
120 Litre POWERflow 2000 129 mins 24 mins
150 Litre POWERflow 2000 115 mins* 25 mins
180 Litre POWERflow 2000 145 mins* 25 mins
210 Litre POWERflow 2000 166 mins* 26 mins
300 Litre POWERflow 2000 175 mins* 25 mins
Time to re-heat 70% to 60°C Direct (3kW) Indirect**
75 Litre POWERflow 2000 73 mins 12 mins
120 Litre POWERflow 2000 110 mins 16 mins
150 Litre POWERflow 2000 101 mins* 18 mins
180 Litre POWERflow 2000 125 mins* 19 mins
210 Litre POWERflow 2000 128 mins* 20 mins
300 Litre POWERflow 2000 135 mins* 21 mins
*Using both Immersions
**If adequate boiler power

WIRING DIAGRAM TWO 2 PORT ZONE VALVE (S-PLAN)
DUAL THERMOSTAT WIRING
8
INDIRECT POWERflow 2000 WIRING DIAGRAM
2PORT (HTG)
HIGH LIMIT
CUTOUT
CONTROL
STAT 2PORT (DHW)
Br GBl C
E E
1 1 2 C GBr Bl 0
1
0
10 WAY WIRING CENTRE 12345678910
1 2 3 4
ROOM STAT
L N HTG
ON
DHW
ON
DHW
OFF
PROGRAMMER
LSL N
BOILER
L
N
PUMP
5A SUPPLY
KEY: Bl=Black, Br=Brown, C=Common Terminal, E=Earth, G=Grey, G/Y=Green/Yellow, L=Live, N=Neutral, O=Orange, SL=Switched Live, W=White
Note: The programmer and boiler power can be taken either from the Wiring Centre or from elsewhere as appropriate.
EE
E
3 PORT
Mid Position
HIGH LIMIT
CUTOUT
CONTROL
STAT 2PORT (DHW)
W G Bl C
E E
1 1 2 C GBr Bl 0
212
0
10 WAY WIRING CENTRE 1 2
LN
345678910
1 2 3 4
2
ROOM STAT
L N HTG
ON
DHW
ON
DHW
OFF
PROGRAMMER
LSL N
BOILER
L
N
3
2
PUMP
5A SUPPLY E
212
LN
2
3
2
E
EE
E
WIRING DIAGRAM 3 PORT MID POSITION VALVE (Y-PLAN) + 2 PORT VALVE
DUAL THERMOSTAT WIRING

9

DATE SERVICED BY COMMENTS
10
ANNUAL SERVICE RECORD
IMPORTANT -Failure to install the cylinder correctly and maintain
this record accurately, will invalidate the manufacturer’s warranty.

McDONALD ENGINEERS
HOT WATER SYSTEMS
FLEMINGTON ROAD, QUEENSWAY INDUSTRIAL ESTATE, GLENROTHES FIFE KY7 5QF
Tel : [phone] Fax : [phone]
Email : [email protected] Internet : www.mcdonald-engineers.com
SOLAR COILS
The cylinder should be installed according to the standard POWERflow 2000 instructions.
Single Coil Solar POWERflow 2000
The Dual Thermostat and 2 Port Motorised Zone Valve should be installed and connected as per
the standard installation and wiring instructions. The Motorised Zone Valve may be omitted, if
the high limit thermostat is wired so as to cut power to the solar pump, in the event of an
overheat situation. Reference should be made to the solar equipment instructions.
Dual Coil Solar
The upper Primary Coil, which is linked to a boiler, should be wired as per our standard wiring
instructions on page 8. The lower Solar Coil should be wired as per the above instructions for
Single Coil Solar . Reference should be made to the solar equipment instructions.
Maintenance:
As per the instruction booklet and any requirements that the Solar Equipment dictates.
REF:07/05