OSO Termo RS, Termo Plus, termo Plus-E, termo RS-E, Termo RS-M Quick Manual

oso termo electric boilers

A unique domestic electric boiler from OSO with the advanced technology of a commercial boiler

Clean
100% Efficient
Flueless
Quiet

- builds water heaters for the future

The OSO Termo is a 100% energy efficient,
intelligent modulating electric boiler, combining
proven commercial technology in a unique
design to bring the consumer one of the most
up to date and efficient electric boilers on the
market. Termo boilers can heat an indirect hot
water cylinder and a wet central heating
system, be it radiators, under floor or a mixture
of both with all the ease and controllability of
a gas or oil boiler.

Termo boilers are available with a choice of
2 heating control packages, Electronic (E) or
Electro-Mechanical (M).

E versions boilers are supplied with a fully
integrated outside temperature sensor. This
intelligent device consistently monitors the
outside temperature – the resulting information
being constantly relayed to the unique in-built
heating curve software. This exceptional
advantage offered by OSO can reduce energy
consumption by as much as 20%. (Further
heating curve information shown on page 9.)

E version boilers supplied for connection to hot
water cylinders are also supplied with a
cylinder temperature sensor that relays the
temperature information back to the boiler.

M versions boilers are supplied without the
heating curve software and do not have an
integrated outside temperature sensor.
Boiler operation is via standard boiler control
principles with the temperature and heating
controlled by room and cylinder thermostats.

Space heating only boilers are also available.

When ordering or specifying an OSO Termo
boiler the E or M version should be clearly
stated.

Underfloor heating (UFH) requires lower primary
flow temperatures than a conventional radiator
system. At OSO we have recognised this fact
and have our boilers in-built with an easily set
manually operated switch that ensures the
correct primary flow temperature range is
selected for the installed heating system.

2

4 Termo RS ● Boiler only

Termo RS-E ● Suitable for space heating and or water heating to

cylinder using an S or Y plan system

Termo RS-M ● Will require expansion vessel, pump and zone valves

5 Termo Plus ● Sealed system boiler

Termo Plus-E ● Suitable for space heating only
Termo Plus-M ● Factory fitted expansion vessel and pump included

6-7 Termo PTV ● Sealed system boiler

Termo PTV-E ● Suitable for space heating and water heating to

cylinder without the need of zone valves

Termo PTV-M ● Factory fitted expansion vessel and pump included

8 Technical Data

9 Heating Curves and Tarrifs

versatile

contents

3

The OSO Termo range of stylish compact boilers
have a multitude of features that will benefit the
developer, builder and installer, one such benefit
where flue arrangements from a gas or oil boiler
are difficult, or impossible to site, or where gas is
not available, the OSO Termo in these
circumstances offers a cost effective solution to
these problems.

Termo electric boilers do not require an annual
safety certificate.

Power surges are eliminated in all boilers by a
two or three stage soft start. All OSO Termo
boilers are available with power outputs of 4.8,

6.0, 7.2, 10.8 and 14.4kW for connection to a
single-phase 240-volt supply – Termo boilers can
be connected in parallel thus increasing total
output.

OSO Termo boilers are almost silent in operation,
carry a three year guarantee and require minimal
maintenance.

4

The Termo RS can be used with the OSO cascade power limiter

(see page 10 for details).

The Termo RS can be used as an

additional, parallel source of heating, or

as an independent heat source.

Both versions of the Termo RS are

compact and easy to install.

Features include an easy to read digital

temperature display, state of the art PCB

control panel and a RCD safety switch.

The Termo RS-E version boiler is supplied

with inbuilt heating curve software,

outside temperature sensor and a hot

water cylinder sensor. Further information

about heating curves can be found on

page 9.

termo rs-e
termo rs-m

1 Primary flow to heating and cylinder
2 Combined heating and cylinder primary return
3 Boiler case
4 Boiler
5 Armaflex insulation
6 Electric elements
7 Control panel
8 Mains power entry
9 Contactors
10 Charge and discharge valve

5

termo plus-e
termo plus-m

Termo Plus is a space heating only boiler
specifically designed for use with a wet
central heating system containing either
radiators, UFH or a combination of both.

The Termo Plus boiler is a self contained unit
that includes a state of the art PCB control
panel, easy to read digital temperature
display, RCD safety switch, primary expansion
vessel and a circulation pump. This compact
boiler ensures a simple, less complicated on
site system and boilers that are easy and
quick to install.

As well as a choice of power ratings the
Termo Plus-E is supplied with our unique
heating curve software and outside
temperature sensor – a correctly set heating
curve working in conjunction with the outside
temperature sensor will ensure only the
required amount of energy will be used to
maintain the dwelling at the consumer set
temperature.

The Termo Plus can be used with the OSO cascade power
limiter (see page 10 for details).

1. Primary flow

2. Primary
return

3. External
boiler jacket

4. Boiler

5. Armaflex
insulation

6. Electrical
heaters

7. Control panel

8. Cable entry
point

9. Contactors

10. Expansion
vessel

11. Circulation
pump

12. Safety valve

2.5 bar

13. Automatic air
vent (AAV)

14. Charge and
discharge
valve

15. Manual air
vent

16. Air-indicator

17. Manifold

18. RCD switch

19. Pocket with
temperature
probe

20. Pressure
probe

termo ptv-e
termo ptv-m

6

The Termo PTV is a sealed system
boiler, specifically designed to provide
heat to a wet radiator system, under
floor heating, or both and an indirect
cylinder, vented or unvented, by
means of the factory fitted twin pump
arrangement.

Supplied with the Termo PTV-E is a
temperature sensor which measures
the temperature of the stored water in
the cylinder. When heat is required to
the cylinder the intelligent controls
read the temperature of the cylinder
stored water and adjust the output
from the boiler using only the required
amount of energy to raise the cylinder
contents to the desired temperature.

The Termo PTV-E can be used in
conjunction with any standard or
programmable room thermostat and
systems incorporating thermostatic
radiator valves.

The Termo PTV-E and Termo PTV-M can be used in
conjunction with the OSO Power Cascade Limiter, see page 10.

The Termo PTV-E version boiler is supplied with inbuilt
heating curve software, outside temperature sensor and a
hot water cylinder sensor. Further information about
heating curves can be found on page 9.

Digital control panel showing heating curve settings,
air in boiler indicator and primary temperature and
pressure gauge.

7

The Termo PTV-E boiler is a self contained unit that includes a state of the art PCB control panel, easy to read

digital temperature display, RCD safety switch, primary expansion vessel, outside temperature sensor and

circulating pumps ensuring a simple, less complicated on site system and boilers that are quick and easy to install.

Termo PTV-M

This boiler is similar in construction to the PTV-E but is not supplied with an outside temperature sensor, heating

curve or a cylinder temperature sensor. When using the Termo PTV-M the temperature of the cylinder and boiler

firing is controlled by the cylinder thermostat. The Termo PTV-M can be used in conjunction with any standard

programmable room thermostat and system incorporating thermostatic radiator valves.

Further information about heating curves and a boiler selection chart can be found on page 9.

termo ptv-e
termo ptv-m

Termo PTV-E

1 Primary flow to heating
2 Combined heating and cylinder primary return
3 Boiler case
4 Boiler
5 Armaflex insulation
6 Electric elements
7 Control panel
8 Mains power entry
9 Contactors
10 Expansion vessel
11 Heating pump
12 Safety valve
13 Automatic air vent (AAV)
14 Charge and discharge valve
15 Manual air vent
16 Air in boiler detector
17 Manifold
18 RCD switch
19 Pump to cylinder
20 Primary flow to cylinder

termo rs-e
termo rs-m

4.8
6

7.2

10.8

14.4

Power

kW

7.5

Cap.

Lit.

A 330
B 750
C 230
D 100
E57
F 126

Dim.

Mm

21.4

Dry

Weight

kg

0.25 (2.5)

Maximum

operating

pressure

MPa (bar)

3/4"

240V N ~

50/60 Hz

Conn.

Power

Supply

termo plus-e
termo plus-m

4.8
6

7.2

10.8

14.4

Power

kW

6

Cap.

Lit.

A 330
B 930
C 230
D 100
E65
F 320

Dim.

Mm

34.5

Dry

Weight

kg

0.25 (2.5)

Maximum

operating

pressure

MPa (bar)

3/4"

240V N ~

50/60 Hz

Conn.

Power

Supply

technical information

termo ptv-e
termo ptv-m

4.8

6

7.2

10.8

14.4

Power

kW

10

Boiler Cap. Lit.

A 400
B 930
C 230
D 150
E65
F 150
G50
H 305

Dimensions

Mm

44.2

Dry Weight

kg

0.25 (2.5)

Maximum operating

pressure MPa (bar)

3/4"

(cylinder)

1"

(heating)

240V N ~ 50/60 Hz

Connection Power Supply

8

Heating curves are a well established concept used
when designing commercial heating and ventilating
systems, but have never been widely used or
adopted in the UK for domestic installations – OSO
now bring this unique and energy saving feature to
the UK in our termo range of electric boilers.

By correctly setting the heating curve software
contained in the E version of the Termo electric boiler
energy consumption can be reduced by up to 20%.

The intelligent controls used monitor the outside
temperature in conjunction with the desired room
temperature and adjust the boiler output to only
supply enough energy to achieve the desired internal
temperature. The colder it is outside, the more heat
is required inside.

Heating requirements for properties vary according to
insulation levels and occupier preference. Choosing
the correct curve will depend upon the insulation
property of the building. Better insulated buildings
will have a lower heating curve and require less heat
than poorly insulated buildings.

The Termo boiler software contains several heating
curves to cover most eventualities.

Termo boilers have factory set heating curves to
match the 2000 Insulation Requirement of the
Building Regulations. Full guidance to the selection
of an appropriate heating curve is given in the easy
to use installation and user manuals.

Note: Heating curve software is only installed in the
E version of the OSO Termo Electric boiler.

A number of off peak electricity schemes are available*.

Economy 7*:

Will require two meters installed in the home.

Economy 7 tariff is not recommended with Termo
boilers as power will not be available to the boiler
during peak periods.

Economy 10*:

Requires one meter

Off peak times are generally set for
Midnight to 05.00 (gmt) 5 hours

13.00 – 16.00 (gmt) – 3 hours

20.00 – 22.00 (gmt) – 2 hours
Times vary with electricity suppliers.

Economy 14*:

Requires one meter

Includes a long off peak time at night and other off
peak times available during the day. Times vary with
electricity suppliers.

By operating your Termo electric boiler with our
unique outside temperature compensator you can be
assured that your system will operate at its most
efficient and reduce / save energy – our electric
boilers are 100% efficient

The Termo electric boiler is versatile and can be
installed singly or as multiple units. Our boiler is easy
to site and can be fitted wherever there is an
electricity supply.

* You should make enquires with your electricity supplier
as to what tariff and duration are available in your area.

heating curves

electricity tariffs

9

Feature RS-M RS-E Plus-M Plus-E PTV-M PTV-E

Suitable for open vented heating systems
Suitable for sealed heating systems
Suitable for water heating to an indirect cylinder
Suitable for sealed system without the need for S or Y plan system
Hot water cylinder sensor
Outside temperature sensor
Inbuilt 10 litre expansion vessel
Inbuilt 8 litre expansion vessel
Inbuilt 3 speed heating pump
Inbuilt 3 speed pump to cylinder
Two or three stage soft start
Inbuilt heating curve software
Air in boiler indicator
Low voltage warning light
Cascade power limiter option
240V single phase power supply
3 Year Guarantee
BEAB Approved

Y
Y
Y
Y
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Y
Y
N
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y

Y
Y
Y
Y
N
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Y
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Y
Y
Y
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Y
Y
Y
Y
Y
Y

Y
Y
N
Y
N
Y
N
Y
Y
N
Y
Y
Y
Y
Y
Y
Y
Y

Y
Y
N
Y
N
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Y
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Y
N
Y
Y
Y
Y
Y
Y

Y
Y
Y
N
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N
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Y
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Y
Y
Y
Y
Y
Y

Y
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N
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Y
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Y
Y
Y

E15 Marquis Court, Team Valley Trading Estate, Gateshead, NE11 0RU

t: [phone] | f: [phone] | e: [e-mail] | w: www.oso-hotwater.com

The company reserves the right to alter size, shape and specification without prior notice.

BEAB Approved. Manufactured in a BS EN ISO 9001:2000 registered factory.

issue3:august09

10

Unique to OSO is the cascade automatic power limiter*. The power limiter is fitted on site between the boiler
and the meter – the cascade unit continually monitors the electricity consumption of the dwelling and will
automatically power down the boiler in situations where medium to high power consumption is being
detected – once the electrical load returns to low usage the cascade unit will allow full power back to the
boiler should it be required. (*Supplied as an optional extra.)

THE ELECTRIC BOILER THAT LOOKS AND THINKS LIKE A GAS BOILER

● No annual safety check

● No flue system or fans required

● No need for bulk oil storage tanks and the associated maintenance

● All electric elements are bottom entry to heat exchanger thus ensuring they are always in water

● 2 or 3 stage soft start feature ensures no power surges

● Suitable for use on open vented or sealed heating systems.

● Three year guarantee

● Minimal maintenance and service cost

● Compact system boiler quick and easy to install

● Suitable for use with a wet radiator system, under floor heating or a mixture of both

● Almost silent operation

● E - version boilers are supplied with heat curve software to reduce energy usage

● M - version boilers are supplied to operate with standard central heating controls

The OSO Termo range of stylish compact boilers have a multitude of features that will benefit the developer,
builder, householder and installer, one such benefit being where flue arrangements from a gas or oil boiler are
difficult, or impossible to site, or where gas is not available, the OSO Termo in these circumstances offers a
cost effective solution to these problems.

oso casade power limiter

- builds water heaters for the future

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