Glowworm MicraCom 24c-AS/1 User manual

Operating instruc-
tions
MicraCom
24c-AS/1
28c-AS/1
GB, IE

Contents
2Operating instructions MicraCom 0020289289_02
Contents
1 Safety ............................................ 3
1.1 Intended use .................................. 3
1.2 Qualification ................................... 3
1.3 General safety information............. 3
2 Notes on the documentation ...... 6
2.1 Benchmark..................................... 6
3 Notes on the documentation ...... 6
4 Product description..................... 6
4.1 Display and control elements......... 6
4.2 Displayed symbols......................... 7
4.3 Data plate ...................................... 7
4.4 Serial number ................................ 7
4.5 CE marking .................................... 7
5 Function........................................ 7
5.1 Operating concept ......................... 7
5.2 Setting the heating flow
temperature ................................... 8
5.3 Setting the domestic hot water
temperature ................................... 8
5.4 Switching off heating mode
(Summer mode)............................. 8
6 Care and maintenance ................ 9
6.1 Caring for the product .................... 9
6.2 Maintenance .................................. 9
6.3 Guaranteeing the filling pressure
of the heating installation ............... 9
6.4 Checking the condensate
discharge pipe and tundish.......... 10
7 Troubleshooting ........................ 10
7.1 Eliminating faults.......................... 10
7.2 Clearing faults on the product...... 10
8 Decommissioning...................... 11
8.1 Temporarily decommissioning
the product................................... 11
8.2 Permanently decommissioning
the product................................... 11
9 Restarting ................................... 11
10 Recycling and disposal............. 11
11 Guarantee and customer
service ........................................ 11
11.1 Guarantee.................................... 11
11.2 Customer service......................... 11
Appendix ............................................... 12
A Eliminating faults....................... 12
B Troubleshooting ........................ 12

Safety 1
0020289289_02 MicraCom Operating instructions 3
1 Safety
1.1 Intended use
The product is intended as a
heat generator for sealed heat-
ing installations and for do-
mestic hot water generation.
Intended use also includes the
following:
–Using the product while ob-
serving the operating instruc-
tions included for the product
and any other installation
components
–Observing all inspection and
maintenance intervals listed in
the instructions
Any other use that is not spe-
cified in these instructions, or
use beyond that specified in this
document, shall be considered
improper use.
Improper use of any kind is
prohibited.
1.2 Qualification
▶Employ only a qualified com-
petent person to install, con-
vert and set the product.
As the end user, you may carry
out all of the work that is de-
scribed in these instructions.
Exception: This product can be
used by children aged from 8
years and above and persons
with reduced physical, sensory
or mental capabilities or lack of
experience and knowledge if
they have been given supervi-
sion or instruction concerning
use of the product in a safe way
and understand the hazards in-
volved. Children must not play
with the product. Cleaning and
user maintenance work must
not be carried out by children
unless they are supervised.
Work that is described in other
instructions must only be car-
ried out by persons who meet
the requirements described
therein.
1.3 General safety
information
The following sections convey
important safety information. It
is essential to read and observe
this information in order to pre-
vent risk of death, risk of injury,
material damage or environ-
mental damage.
1.3.1 Risk of death from
escaping gas
What to do if you smell gas in
the building:
▶Avoid rooms that smell of
gas.
▶If possible, open doors and
windows fully and ensure
adequate ventilation.

1 Safety
4Operating instructions MicraCom 0020289289_02
▶Do not use naked flames (e.g.
lighters, matches).
▶Do not smoke.
▶Do not use any electrical
switches, mains plugs, door-
bells, telephones or other
communication systems in
the building.
▶If it is safe to do so, close the
emergency control valve or
the main isolator.
▶If possible, close the gas
stopcock on the product.
▶Warn other occupants in the
building by yelling or banging
on doors or walls.
▶Leave the building immedi-
ately and ensure that others
do not enter the building.
▶Notify the gas supply
company or the Emer-
gency Service Provider
[phone] by tele-
phone once you are outside
of the building.
1.3.2 Flue gas
If you smell flue gas:
▶Open all accessible doors
and windows fully to provide
ventilation.
▶Switch off the product.
▶Contact a competent person.
1.3.3 Retroactive changes
▶Never remove, bridge or
block the safety devices.
▶Do not tamper with any of the
safety devices.
▶Do not damage or remove
any tamper-proof seals on
components.
▶Do not make any changes:
–The product itself
–to the gas, supply air, water
and electricity supply lines
–to the entire flue system
–to the entire condensate dis-
charge system
–to the expansion relief valve
–to the drain pipework
–to constructional conditions
that may affect the operational
reliability of the product
▶Ensure that there is an evenly
sufficient combustion air sup-
ply.
1.3.4 Material damage
▶Ensure that the combustion
air supply is always free of
fluorine, chlorine, sulphur,
dust, etc.
▶Ensure that no chemical sub-
stances are stored at the in-
stallation site.
▶Ensure that the heating in-
stallation always remains in
operation during freezing con-
ditions and that all rooms are
sufficiently heated.
▶If you cannot ensure the oper-
ation, have a competent per-

Safety 1
0020289289_02 MicraCom Operating instructions 5
son drain the heating installa-
tion.
▶Only fill the heating installa-
tion with suitable heating wa-
ter and, in cases of doubt, ask
a competent person about
this.

2 Notes on the documentation
6Operating instructions MicraCom 0020289289_02
2 Notes on the
documentation
2.1 Benchmark
Glow-worm is a licensed member of the
Benchmark Scheme which aims to im-
prove the standards of installation and
commissioning of domestic heating and
hot water systems in the UK and to en-
courage regular servicing to optimise
safety, efficiency and performance.
Benchmark is managed and promoted
by the Heating and Hotwater Industry
Council. For more information visit
www.benchmark.org.uk.
▶Please ensure that the installer has fully
completed the Benchmark Checklist on
the inside back pages of the installation
instructions supplied with the product
and that you have signed it to say that
you have received a full and clear ex-
planation of its operation. The installer
is legally required to complete a com-
missioning checklist as a means of
complying with the appropriate Build-
ing Regulations (England and Wales).
All installations must be notified to Local
Area Building Control either directly or
through a Competent Persons Scheme.
A Building Regulations Compliance Certi-
ficate will then be issued to the customer
who should, on receipt, write the Notifica-
tion Number on the Benchmark Checklist.
This product should be serviced regularly
to optimise its safety, efficiency and per-
formance. The service engineer should
complete the relevant Service Record on
the Benchmark Checklist after each ser-
vice.
The Benchmark Checklist will be required
in the event of any warranty.
3 Notes on the
documentation
▶Always observe all operating instruc-
tions enclosed with the installation com-
ponents.
▶Store these instructions and all other
applicable documents for further use.
These instructions apply for the following
products only:
Product article number
Article
number
Gas Coun-
cil Number
MicraCom 24c-
AS/1 (H-GB)
0010026136 47-019-58
MicraCom 28c-
AS/1 (H-GB)
0010026137 47-019-59
4 Product description
This product is a gas-fired wall-hung con-
densing boiler.
4.1 Display and control elements
Control
element
Operation
–Switch the product on/off
–Activate/deactivate standby
mode

Function 5
0020289289_02 MicraCom Operating instructions 7
Control
element
Operation
–Go back one level
–Calling up the menu
–Confirming the selection
–Reducing or increasing the set
value
–Scrolling through menu entries
4.2 Displayed symbols
Sym-
bol
Meaning
Burner in operation
Heating mode active:
–Permanently on: Target heating
flow temperature
–Flashing: Current heat demand +
target heating flow temperature
displayed
Domestic hot water generation act-
ive:
–Permanently on: Target domestic
hot water temperature
–Flashing: Current domestic hot
water demand + target domestic
hot water temperature displayed
Installer level active
Current system pressure:
–Flashing: Current filling pressure
Warning if a fault occurs
4.3 Data plate
The data plate is mounted on the rear of
the electronics box and on the upper side
of the product at the factory.
4.4 Serial number
You can find the serial number on the data
plate and on the sticker on the upper side
of the product.
The serial number and the product desig-
nation can also be found on a sticker un-
der the product's front casing.
4.5 CE marking
The CE marking shows that the products
comply with the basic requirements of the
applicable directives as stated on the de-
claration of conformity.
The declaration of conformity can be
viewed at the manufacturer's site.
5 Function
5.1 Operating concept
The adjustable values and menu items
can be changed using the and
buttons.
Each value change must confirmed using
. The new setting is only implemented
once it has been confirmed.
5.1.1 Basic display
AB
A Screensaver B Basic display
The screensaver (A) appears if no operat-
ing procedure is carried out on the product
for longer than two minutes. The display
either shows the target flow temperature

5 Function
8Operating instructions MicraCom 0020289289_02
(if no control is connected) or the message
on and/or oF (if a control is connected).
The basic display (B) shows the current
product status. If you press a selection
button, the activated function is displayed
in the display.
The functions that are available depend
on whether a control is connected to the
product.
To return to the basic display, press .
5.1.2 Operating levels
The product has two operating levels:
–The end user level shows the informa-
tion and offers setting options which do
not require any special prior knowledge.
–Specialised knowledge is required in or-
der to use the installer level (access for
competent persons). This is therefore
protected by an access code.
5.2 Setting the heating flow
temperature
Condition: No control connected
▶In the basic display, press once to
ensure that the symbol flashes.
◁The set heating flow temperature
appears in the display.
▶Press or to set the required
heating flow temperature.
▶Confirm by pressing .
◁The set temperature flashes twice
rapidly.
Condition: Control connected
▶In the basic display, press once to
ensure that the symbol flashes.
◁on or oF appears in the display.
–on indicates that heating mode is
switched on.
–oF indicates that heating mode is
switched off.
▶If oF is shown in the display, press the
button to switch on heating mode.
▶Confirm by pressing .
◁on flashes twice rapidly.
▶Set the required heating flow temperat-
ure on the control (→Control operating
instructions).
5.3 Setting the domestic hot water
temperature
1. Press twice in the basic display to
ensure that the symbol flashes.
◁The set domestic hot water temper-
ature appears in the display.
Condition: No control connected
▶Press or to set the required
water temperature.
▶Confirm by pressing .
◁The set temperature flashes twice
rapidly.
Condition: Control connected
▶Set the required domestic hot water
temperature on the control (→Control
operating instructions).
5.4 Switching off heating mode
(Summer mode)
Condition: No control connected
▶To switch off heating mode, press .
◁The value of the heating flow tem-
perature appears in the display.
▶Press to reduce the heating flow
temperature and set it to oF.
▶Confirm by pressing .
◁oF flashes twice rapidly, heating
mode is deactivated.
◁The symbol is no longer shown in
the display.

Care and maintenance 6
0020289289_02 MicraCom Operating instructions 9
◁The target domestic hot water tem-
perature is displayed.
Condition: Control connected
▶Switch off heating mode on the control
(→Control operating instructions).
6 Care and maintenance
6.1 Caring for the product
▶Clean the casing with a damp cloth and
a little solvent-free soap.
▶Do not use sprays, scouring agents,
detergents, solvents or cleaning agents
that contain chlorine.
6.2 Maintenance
An annual inspection of the product carried
out by a competent person is a prerequis-
ite for ensuring that the product is perman-
ently ready and safe for operation, reliable,
and has a long working life.
6.3 Guaranteeing
the filling pressure of the
heating installation
6.3.1 Checking the filling pressure of
the heating installation
1. In the basic display, press three
times.
◁The display shows the current filling
pressure value.
◁The symbol flashes in the
display.
2. Check the filling pressure in the
display.
3. If the filling pressure is lower than
0.5 bar (0.05 MPa), top up the heating
installation. (→Page 9)
Note
If the heating installation ex-
tends over several storeys, a
higher filling pressure may be
required for the heating install-
ation. Ask a competent person
for details.
6.3.2 Topping up the heating
installation
Note
Filling the heating installation de-
pends on the actual installation
configuration. If the following steps
are not suitable for the installation,
contact a competent person.
1. Use a hose to connect the filling tap to
a cold water pipe.
2. Open all thermostatic radiator valves in
the heating installation.
3. Open the cold water pipe's water tap.
4. Turn the installation's filling tap on
slowly, fill with water until the required
system pressure is reached, and then
close the filling tap again.
–Required system pressure: 1.0 to
1.4 bar (0.10 to 0.14 MPa)
5. Close the cold water pipe's water tap.
6. Purge all of the radiators at the con-
nection provided (top left or right on the
radiator).

7 Troubleshooting
10 Operating instructions MicraCom 0020289289_02
Note
A purging key can be used for
the purging.
7. Check the system pressure after pur-
ging. (→Page 9)
8. If required, repeat the work steps for
filling and purging.
9. Disconnect the filling tap from the cold
water pipe.
6.4 Checking the condensate
discharge pipe and tundish
The condensate discharge pipe and tun-
dish must always be penetrable.
▶Regularly check the condensate dis-
charge pipe and tundish for faults and,
particularly, for blockages.
You must not be able to see or feel any
obstructions in the condensate discharge
pipe and tundish.
▶If you notice a fault, have it eliminated
by a competent person.
7 Troubleshooting
Danger!
Risk of death caused by im-
proper repair work
▶If the power supply cable is
damaged, never replace this
yourself.
▶Contact the manufacturer,
customer service or a simil-
arly qualified person.
▶If faults occur, proceed in accordance
with the "Troubleshooting" table in the
appendix.
Troubleshooting
▶If you have been unable to eliminate
the fault using the specified measures,
consult a competent person.
7.1 Eliminating faults
–If one or more faults occur, the basic
display switches between the active
fault code(s) and the target heating flow
temperature.
F. →XX →XX °C
–If fault F.22 (system pressure too low)
occurs, the basic display switches
between the active fault code(s), the
current water pressure and the target
heating flow temperature.
F. →22 →X,X bar →XX °C
▶If a fault code (F.xx) occurs, proceed in
accordance with the fault code table in
the appendix.
Eliminating faults
▶If you have been unable to eliminate
the fault using the specified measures,
consult a competent person.
7.2 Clearing faults on the product
▶Press and hold the on/off button
in the basic display for longer than
three seconds to reset the product
(maximum five times).
◁rE is shown in the display.
▽rE flashes rapidly after five reset
attempts.
▶Press to stop the flashing and
to restart the product.

Decommissioning 8
0020289289_02 MicraCom Operating instructions 11
8 Decommissioning
8.1 Temporarily decommissioning
the product
1. In the basic display, press the on/off
button .
◁The display goes out.
2. Only close the gas stopcock on the
product if no frost is expected.
3. Close the cold-water isolation valve.
8.2 Permanently decommissioning
the product
▶Have a competent person permanently
decommission the product.
9 Restarting
1. Open the gas stopcock on the product
if the gas stopcock is closed.
2. Press .
◁The display shows the basic display.
3. Open the cold-water isolation valve.
10 Recycling and disposal
▶The competent person who installed
your product is responsible for the dis-
posal of the packaging.
If the product is labelled with this
mark:
▶In this case, do not dispose of the
product with the household waste.
▶Instead, hand in the product to a collec-
tion centre for waste electrical or elec-
tronic equipment.
If the product contains batteries that
are labelled with this mark, these batteries
may contain substances that are hazard-
ous to human health and the environment.
▶In this case, dispose of the batteries at
a collection point for batteries.
11 Guarantee and customer
service
11.1 Guarantee
For information on the manufacturer's
guarantee, you can write to the contact ad-
dress that is provided on the back page
or by visiting https://self-service.glow-
worm.co.uk/warranty-registration/step-
one/.
11.2 Customer service
For contact details for our customer ser-
vice department, you can write to the ad-
dress that is provided on the back page, or
you can visit www.glow-worm.co.uk.

Appendix
12 Operating instructions MicraCom 0020289289_02
Appendix
A Eliminating faults
Message Possible cause Measure
F.22
System pressure too
low
Water deficiency in
the heating installation
1. Check the filling pressure of the heating
installation. (→Page 9)
2. Fill the heating installation. (→Page 9)
F.28
Ignition unsuccessful
After three unsuc-
cessful ignition at-
tempts, the product
has switched to fault
mode.
1. Check whether the gas stopcock is open.
2. Eliminate faults in the product. (→Page 10)
3. Check at the gas meter that gas is still
being supplied to the product.
◁If you have not topped up your payment
recently, the gas supply could be cut off
by the meter.
4. If you are unable to eliminate the ignition
fault, contact a competent person.
B Troubleshooting
Symptom Possible cause Measure
Product does not start
up (no hot water,
heating remains cold)
The installation's gas
stopcock and/or the
gas stopcock on the
product is closed.
▶Open both gas stopcocks.
The gas supply is
interrupted.
▶Arrange payment by the appropriate means
to ensure that your gas supply is restored.
The power supply in
the building is discon-
nected.
▶Check the fuse in the building. The product
automatically switches back on when the
power supply is restored.
The cold-water stop-
cock is closed.
▶Open the cold-water stopcock.
The product is
switched off.
▶Eliminate faults in the product. (→Page 10)
The room temper-
ature/domestic hot
water temperature
has been set too
low and/or heating
mode/domestic hot
water mode has been
switched off.
1. Set the room temperature.
2. Set the domestic hot water temperature.
(→Page 8)
There is air in the
heating installation.
▶Inform a competent person in order to have
the heating installation purged.
Heating will not start
(hot water generation
OK)
The external control
has not been paramet-
rised correctly.
▶Set the external control correctly (→Control
operating instructions).

0020289289_02 ‒06.04.2020
Publisher/manufacturer
Vaillant Group UK LTD
Nottingham Road ‒Belper ‒Derbyshire DE56 1JQ
Telephone [phone] ‒Technical helpline 0330 100 7679
After sales service 0330 100 3142
www.glow-worm.co.uk
© These instructions, or parts thereof, are protected by copyright and may be
reproduced or distributed only with the manufacturer's written consent.
Subject to technical modifications.
0020289289_02