CHAFFOTEAUX Flexiflame 280 Operating and maintenance manual

Flexiflame280&420WT
Installation,Maintenance
and
Operating Instructions
The installation of these boilers must be carried out by a competent person

INTRODUCTION
The Flexiflame 280 and 420 are developments of the wide-
ly used Flexiflame 140 and comprise two or three stan-
dard boiler assemblies connected together in one casing.
The boiler assemblies (modules), each with an output of
41 kW (140,000 Btu/h), are mounted vertically above each
other providing high output to floor space and high output
to weight ratios.
The Flexiflame 280 and 420 are supplied with flanged wa-
ter and gas connections to allow the simple connection of
second or subsequent boilers. Each boiler has an integral
common flue and is contained in a pre-assembled case
that permits easy access for installation and maintenance.
1. Steel chassis.
2. Aluminium flue duct.
3. Copper finned tube heat exchan-
ger.
4. Steel, dry wall, lined, combustion
chamber.
5. Gas section. ON/OFF with two
stage gas valve for quiet and stable
ignition.
6. Water section. Differential pressu-
re, water section assures gas valve
cannot open until pump (IO) is opera-
ting.
7. Flame spillage overheat thermo-
stat.
8. Flow isolating valve.
9. Return isolating valve.
10. Grundfos pump.
11. High temperature overheat ther-
mostat.
12. Stainless steel all gas burner with
permanent pilot and thermo-electric
valve flame failure protection.
13. Piezo ignitor.
14. Levelling bolts.
15. Boiler thermostat and electrical
connection box.
16. Flanged gas header.
17. Flanged water monotube (insula-
ted).
18. Double pole isolating switches for
each module.
19. Fuses for each module.
20. Built in draught diverter. (Fitted
on Flexiflame 280 supplied separate
with the Flexiflame 420.)
DESCRIPTION
Fig. 1
Please note - If side panels are required to complete an installation, please consult installation instructions section 4 before
ordering boilers.
INSTALLATION AND OPERATING FEATURES
The Flexiflame 28C and 420 are designed to be used in
installations where space for plant accomodation is limi-
ted, and where modulating output is a requirement. Three
features distinguish these boilers from others of compara-
ble output.
Compact Construction - The materials and methods of
construction produce the following output to floor space
ratios.
CORVEC Flexiflame 280 - equivalent to 268 kW/m2
CORVEC Flexiflame 420 - equivalent to 399 kW/m2
These ratios will be of particular significance where exis-
ting plant rooms are required to provide higher output,
and where roof top installations are under consideration.
System design - The use of a unique monotube water
flow arrangement obviates the need to include boiler re-
sistance in pump sizing. Each module is provided with a
pump to overcome the resistance of the associated heat
exchanger. The modules are connected in parallel to a
single water flow pipe (monotube) flanged at each end for
simple connection to the system or additional boilers. This
arrangement simplifies design, particularly in changeover
installations where existing pump sizes may not be
known. The boilers must be used with indirect systems
and should only be used in multiples. The 280 should not
be less than 2 off and the 420 not less than 3 off.
Controls-The boilers are fitted with simple controls suita-
ble for use in a wide variety of applications. On/off control
2

of modules is by starting and stopping the associated
pump either under the influence of the boiler thermostat or
an external control signal. Each boiler is fitted with a varia-
ble setting thermostat that brings modules under fire at
1 OC intervals. Where more than one boiler is installed,
continuous sequencing of modules can be effected, either
by using boiler thermostats or by using an external signal
from a step controller. Each module also includes a water
stopping device that prevents unnecessary water circula-
tion through unfired modules.
The boilers are arranged in series to provide increments
of temperature rise to match variations in load and hence
return water temperatures. The boilers are designed for a
system temperature drop of 20 OC (36 OF), but the mono-
tube arrangement provides a built-in by pass feature for
temperature differences of less than 20 oC. Figures 3 and
4 show a typical boiler arrangement and a schematic
layout of a single boiler.
The Flexiflame 280 & 420 boilers must only be used with
indirect fully pumped systems.
The system circulating pump should be sized relative to
the resistance of the connected load and the system des-
ign At selected. The mass flow rate through the monotube
should not be less than 0.6 I/s (8.1 gpm) per module and
the temperature difference across the monotube should
not be greater than 20” C.
Example :
2 x model 280 = 4 modules = minimum flow rate through
the monotube of 2.45 I/s (32.4 gpm)
2 x model 420 = 6 modules = minimum flow rate through
the monotube of 3.68 I/s (48.6 gpm).
DIMENSIONS
Fig. 2
c
9
A 1640 64.5 2142 84.3
8 711 28 711 28
C 430 16.9 430 16.9
0 1410 55.6 1912 75.2
E 1268 49.2 1110 69.7
F 250 10 250 10
G 260 10.25 260 10.25
H 112 4.4 112 4.4
J 305 12.0 305 12.0
K 160 6.3 160 6.3
Flexiflame 280
mm ins
Flexiflame 420
mm ins
EXAMPLE OF BOILER ARRANGEMENT
Flange ‘Flange
CHLOOS/OlO Gasket CHLOOS/OlO
CHLi07 Flange dHL 008
---mfomm
Fig. 3 Fig. 4
3

DESIGN DATA
The installation of the boiler(s) must be in accordance with
the relevant requirements of the Gas Safety Regulations,
building regulations, I.E.E. Regulations and the byelaws of
the local Water Undertaking.
It should be in accordance also with any relevant require-
ments of the local gas region and local authority and the
relevant recommandations of the following documents :
The Building Regulations - 1976
The Gas Safety Regulations - 1972
The Public Health Act - 1936
British Gas Publications - Flues for Commercial and Ins-
dustrial Gas Fired Boilers and Air Heaters (1979)
“Combustion and Ventilation Air - Guidance Notes for
Boiler Installations in excess of 586 kW output”
British Standards
BS 864 : Part 2 - “Capillary and compression tube fittings
of copper and copper alloy”
BS 1387 - “Steel tubes and tubulars suitable for screwing
to BS 21 pipe threads”
BS 2871 : Part 1 - “Copper tubes for water gas and sanita-
tion”
BS 2871 : Part 2 - “Copper and copper alloy tubes for ge-
neral purposes”
BS 4504 : Part 1 - Flanges and Bolting for pipes, valves
ans fittings
Code of Practice
BS CP 331 : Part 3 -“Gas supplies to appliances”
BS CP 332 : Part 3 : 1970 (4.5) - “Air for Combustion and
Ventilation for Installations of up to 586 kW output”
BS CP 341 300 - 307 - Central Heating by low pressure
* hot water
BS CP 342 - Centralized hot water supply :
Part 1 - Individual dwellings
Part 2 - Buildings other than individual dwellings
Chaffoteaux Limited Services - Chaffoteaux Limited are
delighted to assist with technical and design enquiries on
all the product range. Chaffoteaux Limited do not normal-
ly prepare working drawings for installations, but all
Consultants and Designers are encouraged to submit
their proposals to the Company for comment.
Chaffoteaux Limited have Technical Advisers, who, for a
normal fee to cover travelling and time, are available to
commission installations throughout the United Kingdom.
We will attend on site if appliance problems exist, but only
where the installer will be present and when Representati-
ves of other manufacturers who may be involved are pre-
sent.
INSTALLATION INSTRUCTIONS
1) Handling the boiler - The boilers are delivered fully
assembled in wooden crates.
The draught diverter is packed separately in the Flexifla-
me 420.
The delivered weights are 113 kg (280) 155 kg (420).
Remove the wooden crate and any other packing mate-
rials.
Remove the accessory boxes and gaskets from within the
boiler casing.
Do not lie the boiler on its back.
2) Positioning the boiler - Check that the proposed boi-
ler location is sufficiently strong to take the weight of the
boilers and other components.
No purpose made plinth is required for reasonably even
floors.
Position the boilers away from adjacent walls by a mini-
mum of 100 mm (4”). The boilers are self supporting and
do not need to be fixed to the structure.
Level the boiler using the bolts provided in the accessory
box (14-fig. 1).
3) Connecting the boilers - For multi boiler installations
fit the intermediate gaskets and bolt up the flanges.
Do not connect the end appliances to the system before
reading 4.
4) Side panels - Side panels are not supplied with the
boilers.
If side panels are required, the following accessories are
available from Chaffoteaux Limited.
Component Part N’
Side panel for 280 (left andright) . 60675106
Side panel for 420 (left andright) . 48580106
Top brackets 280 & 420 (left andright). . 48579
Screws 280/420 (sixof eachrequiredperpanel). 5799113
Nuts 280/420.. . . . . . . . 26501/03
Before connecting end appliances to the system, fit side
panel support brackets.
5) Connecting to system - Mating flanges are not provi-
ded with the boilers.
Should mating flanges not be readily obtainable, the follo-
wing are available from the manufacturer.
Flange Part N’
Blank for gas supply . . . . . . CHL 007
Mating for gas supply screwed 2112” BSP
Internal . . . . . . . . CHL 008
Mating for monotube screwed 4” BSP In-
ternal................................. CHL 009
Mating for monotube, slip on 4” BSP pipe
for welding . . . . . . . . . CHL 010
6) Draught diverter - Fit the draught diverter if supplied
separately to each boiler and complete flue.
7) Electrical connections - Connect the boilers to the
electrical supply as shown in the wiring diagram (fig. 12).
8) Gas connection - The gas supply can be connected
to either end of the flanged manifold. An isolating tap
should be fitted adjacent to the boilers.
9) Water connection - It is important that ttae flow and
return connections are made so the direction of water flow
is from right to left through the boilers.
Fig.5 , Fig. 6
4
Fig. 7

OPERATING AND
COMMISSIONING INSTRUCTIONS
IO) Filling the system - Fill the system slowly. The filling
operation should be carried out with the flow and return
isolating valves on each module (8 and 9 - Fig. 1) fully
open.
11) Lighting the pilots - Open the gas valve on each mo-
dule by turning gas cock in line with pipe (1 - Fig. 5). Press
the gas control spindle (2 - Fig. 5) and hold in. Light the pi-
lot by pressing piezo ignitor (3 - Fig. 5) and wait for ap-
proximately 20 seconds.
Release the gas control spindle (2 - Fig. 5) and the pilot
should remain alight. If the pilot will not establish, check
that the gas supply to each boiler is purged of air.
Repeat the lighting procedure.
12) Firing the modules - Establish the pilots on all modu-
les as in 11.
Set the boiler thermostat on each boiler (Fig. 6) to a mini-
mum, and check that all module isolating switches are off
(18 - Fig. 1). The switches are wired to be on when at (*)
and off when at ” STOP ”
Check that pumps are free by using screwdriver on end of
spindle.
Set the primary circulation pump in operation, and check
that all system circuits are open and will allow circulation.
Turn up the boiler thermostat (Fig. 6) to the required value,
and switch on the individual modules at the isolating swit-
ches. The modules should now fire. Check for gas leaks
and flue spillage.
13) Checking the gas rate-The burner pressure of each
module should be checked before completing the com-
missioning.
Turn off the module to be checked at the isolating switch
(18 - Fig. 1) and remove the cap from the volume governor
(1 - Fig. 7).
Remove the plug from the pressure test point on the end
of the burner manifold and connect a suitable pressure
gauge.
Turn on the module at the isolating switch and adjust the
gas pressure to the value given in Technical Data on page
3.
Earlier models of the Flexiflame 280 and 420 have a knur-
led ring fitted around the gas control spindle.
Where this is fitted, screw in to reduce the gas rate, and
screw outto increase the gas rate (2 - Fig. 5).
14) Setting the boiler thermostats - Where the modules
are operated by an external control signal set the boiler
thermostat to 50 OC above the maximum expected return
temperature.
Where the modules are to be controlled in sequence by
the boiler thermostats, the following table details the inter-
vals between thermostat settings for various design tem-
perature drops around the system.
N” of Interval between thermostat settings OC
Boilers T=SOoC T=lSoC T=lloC T=80C
: 10 7.5 5.5
; 5
2 : i i
2.5
2.5 -
6 34.5 2.5 - -
i 23.5 I - -
- -
Where the interval would be less than 2.5 oC, it is recom-
mended that boilers be grouped in pairs or threes, depen-
ding on the total number.
e.g. 1 - If 5 boilers were installed to provide a flow tempe-
rature of 82 OC at a system drop of 11 oC, the thermostat
settings would be 82, 79.5, 77, 74.5 and 72 oC. The boiler
nearest the flow would be set at 82 OC and the boiler nea-
rest the return at 72 0C.
e.g. 2 - If 8 boilers were installed to provide a flow tempe-
rature of 90 OC at a system drop of 20 oC, the thermostat
settings would be 90, 87.5, 85, 82.5, 80, 77.5, 75, 72.5 OC.
The boiler nearest the flow would be set at 90 0C and the
boiler nearest the return at 72.5 oC.
e.g. 3 - If 12 boilers were installed to provide a flow tem-
perature of 82 OC at a system drop of 11 oC, the thermo-
stat settings would be 82 for boilers 1 and 2, 79.5 for boi-
lers 3 and 4, 77 for boilers 5 and 6, 74.5 for boilers 7 and
8, 72 for boilers 9 and 10, and 69.5 for boilers 11 and 12.
SERVICING REQUIREMENTS
Chaffoteaux Limited recommend that boilers are serviced
annually.
Installers and clients are reminded that the boilers are
guaranteed for twelve months from the date of installation.
Spare parts lists and prices are available from the manu-
facturers.
15-I Remove the boiler doors by removing lower hinge
pin and pulling forwards at the bottom.
Isolate the module to be serviced by turning the isolating
switch off (24 - Fig. 1).
Close the gas isolating valve turning gas cock across pipe
(6 - Fig. 1).
Release the screw (1 - Fig. 8) holding the pilot supply pipe
and remove the pipe (2 - Fig. 8).
Unscrew the union securing the thermocouple to the elec-
tromagnet at the rear of the gas section (4 - Fig. 1). Remo-
ve electrode lead from piezo, remove both overheat and
skirt overheat from heat exchanger, remove complete
electrode and thermocouple bracket assembly from ap-
pliance with the burner assembly.
Remove the screws holding the burner to the back plate
(1 - Fig. 9).
Unscrew the union nut securing the burner to the gas sec-
tion (2 - Fig. 9).
Clean the burner by removing any deposits with a brush.
Fig. 8 Fig. 9

15-2 To remove the pilot
Isolate the module as detailled in 15-l.
Release the screw (1 - Fig. 8) holding the pilot supply pipe
and remove the pipe (2 - Fig. 8).
Unscrew the pilot injector (7 - Fig. 8) and replace if neces-
sary. Do not attempt to clean the pilot injector as this
could result in damage.
15-3 To removethe burner manifold
Isolate the module as detailled in 15-l.
Remove the pilot supply pipe s in 15-2.
Unscrew the manifold retaining screws (3 - Fig. 10) taking
care not to release the fusible overheat link.
Remove the burner manifold and clean away any lint with
a soft brush.
15-4 To remove the heat exchanger
Isolate the module as in 14 and close the flow and return
isolating valves (7 and 8 - Fig. 1).
Remove the burner as in 15-3.
Drain down the module. Remove right and left hand tubes
from heat exchanger. Remove top two front plate screws
and four rear retaining screws and lift out heat exchanger.
Clean the heat exchanger with very hot water and deter-
gent. Do not use wire wool or similar.
Replace the heat exchanger using new washers where ne-
cessary.
Replace the burner.
15-5 To remove the diaphragm
Isolate and drain down the module as in 17.
Disconnect the high and low pressure pipes from the wa-
ter section (2 and 3 - Fig. 11).
Unscrew the retaining screws holding the water section to
the underside of the gas section (4 - Fig. 11).
Remove self tapping screws and bracket under water sec-
tion.
Remove water section.
Remove screws from water section and split into two hal-
ves.
Replace the diaphragm and “0” ring.
Re-assemble water section and refit to module.
Fig. 10 Fig. 11
PI
bode
stat
P2
P3
Fig. 12

Fault finding chart
Fault Possible cause Remedy
Pilot will not light
Pilot goesout 1) Gas control knob not fully held in before
when gasknob is released releasing.
Main burner will not light
or lights at low flame
Complaints of noise
Excessively noisy burner
Frequent sooting
of heat exchanger and burners
Gas staying on after pump
is switched off
1) Gas supply not turned on.
2) Gas supply pipes not purged of air.
3) Blocked pilot filter or injector.
2) Thermocouple not in tip of pilot flame.
3) Pilot flame too soft.
4) Faulty thermocouple or union loose.
5) Main gasvalve not purged.
6) Faulty thermoelectric valve.
7) Overheat failing.
8) Loose connection on overheat
thermostat.
1) Electricity not switched on to boiler.
2) Fusesmissing or blown in control box.
3) Boiler thermostat at low setting.
4) Boiler thermostat faulty or not plugged
into control box.
5) Gas supply insufficient.
6) Lack of water in system.
7) Air in system.
8) Boiler pump faulty.
9) Water filter in return pipe blocked
or high presure and balancing tubes
blocked.
10) Bearing plate spindle bent or dry.
11) Diaphragm split or stretched.
12) Heat exchangerblocked.
1) Over-gassed.
2) Air in system.
3) Boiler thermostat wrongly setor faulty.
4) Water section sticking open.
5) Gas valve sticking open.
6) Dirt/swarfon gasvalve facing.
7) Resistanceto water flow.
8) Pump noise or vibrating.
9) Heat exchanger partially blocked.
1) Over-gassed.
2) Dirty burner bars.
3) Burr on injectors.
1) Linting.
2) Insufficient combustion air to room or
compartment.
3) Heat exchanger fins blocked.
4) Restriction in flue.
5) Wrong injectors fitted.
1) High pressureor balancing tubesblocked.
2) Gas valve sticking open.
3) Water section sticking open.
Turn on.
Purge.
Clean or replace (15-2).
Pressfirmly before releasing.
Adjust (12 milli-volts min. required
measuredat high limit thermostat).
Tighten pilot injector securing nut (15-2).
Replace or tighten.
Repeat ignition sequence.
Replace(l5.1).
Replace (15.1).
Tighten.
Switch on.
Replace 1amp.
Turn up fully.
Replace or check connection.
Check working pressure-8 in w.g.
required at inlet.
Fill.
Purge.
Check or replace (10 - fig. 1).
Remove and clean.
Replace or grease(15-5).
Replace (15-5).
Descale or replace (15-4).
Check gasrate and adjust (13-2 - fig. 5).
Purge.
Check flow temperature.
Check operation and grease(15-5).
Clean or grease.
Clean and reassemble.
Open valves.
Replace or relit (10 - fig. 1).
Clean heat exchanger and check system
(15-4).
Check gasrate (see13 - fig. 5).
Clean (13-3).
Remove or replace.
Clean burner (13-3).
Check requirements.
Remove and wash throughly (15-4).
Check flue.
Check and replace (Page3).
Remove and clean.
Clean and grease.
Clean and grease.
7

TECHNICAL DATA
280 420 280 I 420
output . . . . . . . . . . . .
Input . . . . . . . . . . . . .
Gas Rate . _. . . . . .
Burner Pressure . . . .
Burner Injector Diam.
Pilot Injector Diam. .
81.4 kW 122.1 kW 280,000 Btufh 420,000 Btulh
104 kW 156 kW 354,000 Btu/h 532,000 Btu/h
9.6 m3/h 14.4 m3/h 338 ft3/h 508 ft3/h
15 mbar 15 mbar 6 ins w.g. 6 ins w.g.
1.18mm 1.18 mm 0.046 ins 0.046 ins
0.30 mm 0.30 mm 0.012 ins 0.012 ins
. .
Height ........
Width .........
Depth ........
............... 1640 mm 2142 mm 64.5 ins 84.3 ins
............... 710 mm 710mm 28.1 ins 28.1 ins
............... 430 mm 430 mm 16.9 ins 16.9 ins
Weight ..... .'1 ................. 113kg 155 kg
Water Content ................. 15 litres 18 litres 249 Ibs 3.29 galls 342 Ibs 3.9 galls
Max Flow Temperature .........
Max Return Temperature .......
Min Static Head ...............
Max Static Head ...............
110°C IIO’C
90 “C 90 “C
0.3 bar* 0.3 bar
7.0 bar 7.0 bar
Flue Connection 10 in. 0 (250 mm 0)
Electrical Supply 240 V a.c. 50 Hz
* All combustion data is for natural gas. For data on town and LP gases, please contact Chaffoteaux Limited.
* Minimum static head for flow temperatures not exceeding 82 “C (180 “F).
DESIGN DATA
(i) Hydraulics - The maximum number of boilers that can be installed in series dependent upon the maximum mass flow
capacity of the monotube. The following tables detail the total monotube resistance for installations of up to 2442 kW
(8.3 million Btu/h) output, and for various system design temperature drops.
CORVEC Flexiflame
No. of Total Output Total Length of Total Monotube Resistance in Metres w.g.
Boilers kW Monotube m T=20”C T=15”C T=ll ‘C T=8”C
1 81.4 0.71
2 162.8 1.42
3 244.2 2.13
4 325.6 2.84
5 407 3.55
10 814 7.10
15 1221 10.65
20 1628 14.20
25 2035 17.75
30 2442 21.30
CORVEC Flexiflame
1
122.1 0.71
2 244.2 1.42
3 366.3 2.13
4 488.4 2.84
5 610 3.55
10 1221 7.10
15 1831.5 10.65
20 2442 14.20
Total Monotube Resistance in less than 0.01 Metres w.g.
0.01
0.01 0.01 0.02
0.03 0.04 0.07 0.14
0.07 0.15 0.24 0.46
0.20 0.32 0.58 1.07
0.36 0.62 1.12 -
0.62 1.04 1.91 -
Total Monotube Resistance in less than 0.01 Metres w.g.
I
0.01
0.01 0.02
0.01 0.01 0.02 0.04
0.05 0.10 0.17 0.32
0.17 0.30 0.53 1.02
0.41 0.69 1.27 -
chaffoteauxEn
Chaffoteaux Ltd, Concord House, Brighton Road, Salfords, Redhill, Surrey RH15DX. Telephone: Horley [phone]. Telex: 87378.
ESP025