Baxi Flat roof mounting User manual

© Baxi Heating UK Ltd 2007.
Installation Guide - Flat roof mounting
Solarflo - Solar Thermal Domestic Hot Water System
Please read these instructions before installing or commissioning.
The Solarflo - Solar Thermal Domestic Hot Water System should
only be installed by a competent person.
Please leave these instructions with the user for safe keeping.

© BAXI Heating UK Ltd 2007. All rights reserved. No part of this publication may be reproduced
or transmitted in any form or by any means, or stored in any retrieval system of any nature (includ-
ing in any database), in each case whether electronic, mechanical, recording or otherwise, without
prior written permission of the copyright owner, except for permitted fair dealing under
Copyrights, Designs and Patents Act 1988.
Applications for the copyright owner’s permission to reproduce or make other use of any part of
this publication should be made, giving any details of the proposed use to the following address:
The Company Secretary, BAXI Heating UK Ltd,The Wyvern Business Park, Stanier Way, Derby DE21 6BF.
Full acknowledgement of author and source must be given.
WARNING:Any person who does any unauthorised act in relation to a copyright work may be
liable to criminal prosecution and civil claims for damages.
Solarflo - Solar Thermal Domestic Hot Water System2

Index
3 Index
4 General
Safety information
6 Installation of solar collector
Lifting the panel
General assembly notes
Mounting kit parts list
Attachment points
Mounting system
19 Installation of collector panel sensor
Solarflo - Solar Thermal Domestic Hot Water System 3

Solarflo - Solar Thermal Domestic Hot Water System4
1.0 General
1.1 Safety information
In order to reduce the number of deaths and major
accidents attributable to work at height, the Health and
Safety Executive has introduced comprehensive
regulations and guidance that should be followed by all
businesses working at height.
We consider in the following paragraphs some of the
main features of the regulations and guidance.This is,
however, only a limited summary and it is recommended
that all businesses planning on undertaking solar water
heating installations obtain a copy of the regulations and
guidance issued by the Health and Safety Executive and
carefully consider the contents.
The regulations and guidance state that you are required
to carry out a risk assessment for all work conducted at
height and to put in place arrangements for:
• Eliminating or minimising risks from work at height.
• Safe systems of work for organising and performing
work at height.
• Safe systems for selecting suitable work equipment.
• Safe systems for protecting people from the
consequences of work at height.
The regulations and guidance highlight a
hierarchy for safe work at height:
• Avoid the risk by not working at height if practicable.
• Prevent falls, where it is not reasonably practicable
to avoid work at height; you are required to take suitable
and sufficient steps to prevent the risk of a fall including
selecting the most suitable work equipment (in accordance
with the regulations).
• Mitigate the consequences of a fall; where the risk of
a person or object falling still remains, take suitable
and sufficient measures to minimise the distance and
consequences of any fall.
Collective protection measures, such as guard rails on
scaffold, should be given priority over personal protection
measures, such as safety harnesses.
Within the regulations’ framework, you are required to:
1) Assess the risk to help you decide how to work safely.
2) Follow the hierarchy for safe work at height (i.e. avoid,
prevent and mitigate).
3) Plan and organise your work properly, taking account
of weather conditions and the possibility of emergencies.
4) Make sure those working at height are competent.
5) Make use of appropriate work equipment.
6) Manage the risks from working on or around fragile
surfaces and from falling objects.
7) Inspect and maintain the work equipment to be used
and inspect the place where the work will be carried out
(including access and egress).
When preparing to install a solar water heating system, it
is required that you perform a risk assessment in relation
to work at height and plan how you will organise your
work, taking into account the site, the weather conditions
and the experience and competence of colleagues or
contractors who may be working at height with you.

1.0 General
Risk Assessments
The HSE has published a number of very useful free
publications that advise how to undertake risk assessments.
Two of these that you should obtain are:
Five Steps to Risk Assessment.
A Guide to Risk Assessment Requirements.
The five steps outlined in the HSE leaflet are:
Step 1: Look for the hazards
This will mean looking at the site and identifying
significant hazards.These could be features such as a
steep roof, a fragile surface where the collectors may be
mounted, uneven ground or obstructions where access
to the roof might be required.
Step 2: Decide who may be harmed and how
This might mean considering the particular risks that
young workers or trainees might face and thinking about
the residents of the household or visitors who could be
hurt by your activities.
Step 3: Evaluate the risks and decide which precautions
should be made.You should consider how likely it is that
each hazard will cause harm, decide which precautions
you might take and then assess, after you have taken
those precautions, whether the remaining risk will be
high, medium or low.Where you identify remaining risks,
you should consider which further action you could take
to control the risks so that harm is unlikely.
Step 4: Record your findings
If you have fewer than five employees you do not need to
write anything down, though it is useful to keep a
written record of what you have done. If you employ five
or more people you must record the significant findings
of your assessment.You must also tell your employees
about your findings.You need to be able to show that a
proper check was made, that you considered who might
be affected, that you dealt with all the obvious significant
hazards, that the precautions you propose are reasonable
and that the remaining risk is low.
Step 5: Review your assessment if necessary
Each solar water heating installation may bring its own
challenges and present its own particular hazards.You
should therefore be careful not to rely on a “standard”
risk assessment for installing a solar water heating system
in a house, but review the particular hazards for each
new situation.The issue of work equipment must be
considered, but at the preparation stage you should
consider where scaffold or other access equipment might
be positioned and look out for any obvious obstacles to
this, such as a conservatory or porch.
In addition to the risks associated with work at height,
you should also consider the risks associated with lifting
and carrying solar collectors, using electric drills and
using blow lamps or blow torches for soldering.This is
not an exclusive list and you should consider all aspects
of the proposed installation to assess whether there are
additional risks that need to be taken into account.
Solarflo - Solar Thermal Domestic Hot Water System 5

Solarflo - Solar Thermal Domestic Hot Water System6
2.0 Installation of solar collector
2.1 Lifting the panel
Do not lift the collectors by the connections.
Refer to Section 2.2 of the Installation Guide Solar
Collector Panel specifications for details of the dimensions
and weight of each panel. Carrying/lifting straps must be
securely fastened to the main framework of the panel.
Point impact and loading of the glass panel must be
avoided.The collector must not be installed if the glass
panel is damaged in any way.
Fig. 1

Solarflo - Solar Thermal Domestic Hot Water System 7
2.0 Installation of solar collector
2.2 General assembly notes
These instructions relate to the installation of the Baxi
Solarflo flat plate solar collector panels onto a flat roof
using the Baxi Solarflo Flat Roof Mounting Frame.
These instructions must be followed rather than those
contained in the Baxi Solarflo On roof Flat Plate Solar
Collector Mounting Installation Guide. All other
equipment must be installed as per detailed in the
Baxi Solarflo Installation Guide.
The Flat Roof Mounting Frame may be used to mount
the Baxi Solarflo collector panels at ground level if
required. In these instances particular attention should
be paid to anchoring any mounting beams used to the
ground.Also, during use, some surfaces of the collector
panels and connecting pipework may become very hot
so consideration must be given to prevent access to
children, infirm, aged or unauthorised persons.
Use only Baxi Solarflo mounting systems. Use of other
brackets/mounting systems will invalidate the warranty and
may result in an insecure and dangerous panel installation.
It is recommended that the Bench Screws for mounting
the panel mounting framework are fixed to additional
wooden structural bearers which in turn are attached to
the roof structural members.They must never be fixed
directly to roofing laths or boarding. If suitably positioned
structural members are not available, or of a section that
may be weakened by the insertion of the Coach Screws,
additional noggins should be inserted between the
structural members.These should be at least the same
cross section as the structural member.The timber
bearers should be tanalised and typically have a minimum
section of 150mm x 75mm and be of suitable length to
accommodate the mounting frame (see Fig. 2).
The bearers should be attached to the roof with
corrosion resistant coach screws of sufficient length to
penetrate the main roof support timbers by at least
100mm.The underside of the timber bearers should be
liberally coated with melted tar or liquid bitumen before
fixing in place. At least four fixing points per bearer must
be used.The bearers should be countersunk or bored to
accept the head of the coach screws.When in place the
bearers should be covered using good quality roofing felt
and melted tar or liquid bitumen (see Fig. 3).
If mounting at ground level the timber bearers must be
anchored to the ground into concrete using suitable
corrosion resistant fixings.The timber bearers must also
be treated against long term exposure to weather
conditions.
When assembling the Mounting Frame use only
corrosion resistant fixings supplied. Holes through any
roof water-proofing materials should be sealed with an
appropriate weather resistant sealant.
Joist
Tanalised timber
Roofing felt
Chipboard
100mm
150mm
Fig. 2
Roofing felt
Tanalised
timber
Seal
Fig. 3

Solarflo - Solar Thermal Domestic Hot Water System8
2.0 Installation of solar collector
Structure
The collectors may only be mounted on sufficiently
load-bearing roof surfaces and substructures. It is
essential that the structural load-bearing capacity of the
roof and the substructure must be assessed before
mounting the collectors. Particular attention should be
paid to the quality of the (timber) substructure in terms
of the stability of the screw joints necessary for installing
the collector mountings. Anchor screws must be bolted
into support with a minimum depth of 150mm.Where
roof structure is not strong enough, noggins must be
inserted to accept anchor screws.The roof structure
must be able to take the wind and snow loads that can occur.
(Note: 1m2powder snow ~ 60kg / 1m2wet snow ~ 200kg).
The assessment should also take into account any special
features of the particular site that could lead to increased
loads (air jets or eddy formations, etc).There must be at
least 1m distance from roof ridging or edges.
Lightning protection / Equipotential bonding of
the building
It is not necessary to connect collector arrays to the
lightning protection of the building. For installations on
metal substructures at the installation site, authorised
lightning protection specialists must be consulted.The
metal pipes of the solar circuit must be earth bonded
to the main earthing circuit by means of a conductor
(green/yellow) with a cross-section of at least 6mm2.

Solarflo - Solar Thermal Domestic Hot Water System 9
2.0 Installation of solar collector
Collector panels must be connected in series.The left
hand connection is threaded 3⁄4”BSP male.The right hand
connection has a 3⁄4”BSP female union connection.This
enables the panels to be directly connected to each
other. N.B. ensure the sealing washer provided is inserted
between the male and female connections.All connecting
pipe work and fittings must be of a suitable metal; either
copper, brass or stainless steel. Soft soldered joints must
not be used.Any seals or sealing compounds must be
resistant to temperatures of up to 150°C and be
resistant up to a 50% glycol/water mix.
Connections
When tightening the connections, always apply
counter-pressure with a wrench or another spanner to
prevent damage to the absorber.
Collector inclination
The mounting frame will mount the collector panels at
an angle of 45°.The frame should be orientated such that
the collector panel(s) ideally face South, however
orientations between 30° East and 40° West of South are
acceptable. Fig. 4 shows the efficiency loss for varying
angles of inclination and panel orientation.
Solar fluid
The Baxi Solarflo collector panels MUST be protected
with a water/glycol heat transfer fluid. Use only the fluid
supplied with the system which is supplied pre-mixed to
a concentration of 40% glycol / 60% water.Top ups can
be made with water but the glycol concentration must
not be allowed to fall below 30% or inadequate frost
protection will be given. Systems found to have lower
glycol concentrations will not be covered by the warranty.
10°10°
20°20°
30°30°
40°40°
50°50°
60°60°
70°70°
80°80°
90°
Angle of tilt
North
South
less than optimum by 0-5% 5-10% 10-20%
East
S.E.S.W.
West
90°
Fig. 4

Solarflo - Solar Thermal Domestic Hot Water System10
2.0 Installation of solar collector
2.3 Mounting kit parts list
1 panel 2 panels 3 panels
A. Bench screw 4 4 6
B. Attachment bracket 4 4 6
C. Rubber seal 4 4 6
D. Clamping piece - 1 2
E. Clamping piece extension - 2 4
F. Mounting part top 2 2 2
G. Mounting part extension - 1 2
H. M8 washer 12 17 27
I. M8x30 hammer-head bolt 6 6 8
J. M8 hex nut 12 17 27
K. Support rail 2 4 6
L. Mounting jig - 1 1
M. Sealing washer 2 3 4
N. M12 nut 12 12 18
O. M12 washer 12 12 18
P. M8 Hex head bolt 6 6 9
Q. Rear support bracket 2 2 3
R. Front support bracket 2 2 3
NOTE: 1 sealing washer is supplied with each solar
collector panel. 2 sealing washers are supplied with the
flexible connection pipes.

Solarflo - Solar Thermal Domestic Hot Water System 11
AG
BH
CI
DJ
EK
M
See Note
N
O
FL
P
Q
R

Solarflo - Solar Thermal Domestic Hot Water System12
2.0 Installation of solar collector
2.4 Suggestion for attachment points
NOTE: Some variation may be necessary depending on
the pitch of the roof structural support bearers.
200
350
350 350
35012201690
1690
45
400-600
400-600
45
400-600
200
All dimensions shown in mm
Suggested
attachment
positions
Fig. 5

Solarflo - Solar Thermal Domestic Hot Water System 13
Note: Recommend
sealing hole with
silicon bead prior
to positioning
rubber seal
Roof bearer
100mm
2.0 Installation of solar collector
2.5 FLAT roof Mounting system, parallel
1: Measure the mounting points (for suggested positions
see fig 5) and mount support bearers as recommended
in Section 2.2.
Dimension A = Recommended pitch of supports for
1 and 2 panel system
Dimension B = Recommended pitch of additional
support for 3 panel system
Dimension C = 1460mm (Front to back mounting
positions to give 45º panel inclination).
2: Drill fixing points into bearers using an 8mm diameter
drill (minimum depth 100mm).
3: Fasten bench screws into fixing points, minimum
screw depth >
_100mm.
Attach rubber seal and tighten using M12 washer and
M12 nut.
Order:
- Bench screw
- Rubber seal
- M12 washer
- M12 nut
4: Assemble attachment brackets onto bench screws as
shown.
Order:
- M12 nut
- M12 washer
- Attachment bracket
- M12 washer
- M12 nut
AB
C
1
2
3
45mm
4

Solarflo - Solar Thermal Domestic Hot Water System14
A
B
C
2.0 Installation of solar collector
5. Install first mounting frame as follows:
5a. Attach front support bracket to rear support bracket
as shown and loosely tighten
Order:
- M8 bolt
- Front support bracket
- Rear support bracket
- M8 washer
- M8 hex nut
5b. Attach front support bracket to front attachment
bracket as shown. NOTE position of front support
bracket to attachment bracket, placing the wrong side
of the attachment bracket will prevent correct assembly.
Order:
- M8 bolt
- Attachment bracket
- Front support bracket
- M8 washer
- M8 hex nut
5c. Attach rear support bracket to rear attachment
bracket as shown. NOTE position of rear support
bracket to attachment bracket, placing the wrong side
of the attachment bracket will prevent correct assembly.
Order:
- M8 bolt
- Attachment bracket
- Rear support bracket
- M8 washer
- M8 hex nut
Tighten each attachment point.
5d. Repeat steps above for each mounting frame.
5
5a
5b
5c
5d

Solarflo - Solar Thermal Domestic Hot Water System 15
T-slot
2.0 Installation of solar collector
6. Attach lower mounting rails as shown in 6 with the
hammerhead bolts engaged in the T-slot of the rail.
Order:
- Mounting rail
- Hammerhead bolt
- Front support bracket
- M8 washer
- M8 nut
Ensure rail is horizontal using a spirit level.
NOTE: for 2 panel systems, first join 2 mounting rails
together as shown in steps 8 and 9 before attaching to
the mounting frame support brackets.Attention must be
paid to the correct orientation of the mounting rails to
ensure correct panel mounting.
7. Attach upper mounting rails as shown in 7 with the
hammerhead bolts engaged in the T-slot of the rail.
Order:
- Mounting rail
- Hammerhead bolt
- Front support bracket
- M8 washer
- M8 nut
Ensure rail is horizontal using a spirit level.
NOTE: for 2 panel systems first, join 2 mounting rails
together as shown in steps 8 and 9 before attaching to
the mounting frame support brackets.Attention must be
paid to the correct orientation of the mounting rails to
ensure correct panel mounting.
6
T-slot
7

Solarflo - Solar Thermal Domestic Hot Water System16
8. For 3 panel systems join the additional mounting rails
as shown in steps 9 and 10.
9. Push the clamping piece extension halfway into the
T-slot of the mounting rails (upper and lower) and
tighten.
Order:
- Mounting rail
- Clamping piece extension
- M8 washer
- M8 hex nut
10. Attach the additional mounting rails (upper and
lower) to the mounting frame support brackets.
Order:
- Mounting rail
- Hammerhead bolt
- Front support bracket
- M8 washer
- M8 nut
Repeat procedure for all mounting points.
8
9
2.0 Installation of solar collector
9a
10

Solarflo - Solar Thermal Domestic Hot Water System 17
AB
4545
11: Hang the first collector in the lower mounting rail
and adjust its position so that the frame is 45mm
from the end of the rail as shown.
N.B. Ensure collector panel locating lip is correctly
positioned in the support slot of the lower mounting
bracket.
12: If mounting 2 or more panels place the clamping piece
on the upper mounting rail and hand tighten for now.
Order:
- upper mounting rail
- mounting part extension
- clamping piece
- M8 washer
- M8 nut
13: Using the mounting jig to aid correct positioning
mount the next collector panel. Ensure jig is removed
after fitting (see 13a).
2.0 Installation of solar collector
11
11a
12
13
13a
Mounting jig

Solarflo - Solar Thermal Domestic Hot Water System18
14: Connect the collector panel flow/return pipe
together. Ensure the fibre washer is inserted between
the male and female connections. Support the pipes
when tightening nut.
15: Rotate the clamping piece by 90° so it locates in the
Collector panel locating lip and screw it tight
using a long socket wrench.
16: Attach additional clamping pieces / collectors as
described in points 11-15.
17: Attach the top mounting part on the upper left and
right end of the collector.
Order:
- mounting rail
- hammer-head bolt
- top mounting part
- M8 washer
- M8 nut
18: Connect flexible connection pipes to collector panel
inlet and outlet connections. Ensure fibre washer is
used between connection pipe and connections.
2.0 Installation of solar collector
14
15
16
17
Fibre washer
Collector
inlet/outlet connection
18

Solarflo - Solar Thermal Domestic Hot Water System 19
The Collector panel temperature sensor should be
installed in the sensor pocket nearest to the collector
array flow. It should be secured in the pocket by inserting
through the rubber gland provided. All materials used for
installing temperature sensors (sensor element, conducting
compound, cables, sealing and insulating materials) must
be suitably temperature resistant (up to 250°C).
3.0 Installation of collector panel sensor
Fig. 6

Comp No 3600 5975 - Issue 1 - 5/07
All descriptions and illustrations provided in this leaflet have been
carefully prepared but we reserve the right to make changes and
improvements in our products which may affect the accuracy of the
information contained in this leaflet. All goods are sold subject to
our standard Conditions of Sale which are available on request.
BAXI
A Trading Division of Baxi Heating UK Ltd, a division of Baxi Group.
Brooks House, Coventry Road,Warwick. CV34 4LL
After Sales Service and Technical Enquiries 08700 603261
Our contact centre is open Monday to Friday 8am to 6pm,
Weekends and Bank Holidays 8.30am to 2pm.
We are closed Christmas Day and New Years Day.
Website www.baxi.co.uk
© Baxi Heating UK Ltd 2007.