ESI ESRTERFW, ESRTD3, ESRTD2, ESRTE2 User Instructions

ESRTERFW

Wireless Digital
Room Thermostat

User Instructions

Thank you for choosing ESi Controls.

All our products are tested in the UK so we are
confident this product will reach you in perfect
condition and give you many years of service.
However, for additional peace of mind, we
recommend you register your product online at
www.esicontrols.co.uk/warranty for your
extended warranty.

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User Instructions

What is a Wireless Digital Room Thermostat?
An explanation for householders 4

Thermostat Display 5
What is Chronoproportional Control (TPI)? 5
Setting the Temperature 6

Contents

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An explanation for householders

A room thermostat simply switches the heating system on
and off based on room temperature. It works by sensing
the air temperature, switching on the heating when the air
temperature falls below the thermostat setting and switching
it off once this set temperature has been reached.

Turning a room thermostat to a higher setting will not make
the room heat up any faster. How quickly the room heats up
depends on the design of the heating system, for example,
the size of the boiler and radiators. Neither does the setting
affect how quickly the room cools down. Turning a room
thermostat to a lower setting will result in the room being
controlled at a lower temperature, and saves energy. The
heating system will not work if a time switch or programmer
has switched it off. The house insulation quality is a key factor
in heating control.

The way to set and use your room thermostat is to find the
lowest temperature setting that you are comfortable with,
and then leave it alone to do its job. The best way to do this
is to set the room thermostat to a low temperature – say
18°C and then turn it up until you are comfortable with the
temperature (20°C is the usual preferred set point). You won’t
have to adjust the thermostat further. Any adjustment above
this setting will waste energy and cost you more money.

If your heating system is a boiler with radiators, there will
usually be only one room thermostat to control the whole
house (but building regulations Part L require houses above a

What is a Electronic Room
Thermostat?

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certain size to have more than 1 heating zone).

Room thermostats need a free flow of air to sense the
temperature, so they must not be covered by curtains or
blocked by furniture. Nearby electric fires, televisions, wall
or table lamps may prevent the thermostat from working
properly. Also keep out of direct sunlight.

A Wireless Room Thermostat operates using radio signals
between the unwired battery operated thermostat and
a wired receiver. Put simply the time and sensor part
are separated from the hard wired part. Wireless Room
Thermostats are ideal for use in situations where it is not
possible to hardwire the programmable thermostat back to
the boiler. E.g. retrofit where walls are already decorated or
not suitable for chasing cable through.

N.B. This thermostat has the option of standard setting or TPI.

Thermostat Display

This product has a built in auto-rechargeable battery to power
the display when the system is between heating cycles. To
conserve power this will run for eight hours and if the heating
intervals are more than eight hours apart, the display will
“go to sleep” – although the thermostat is still active. When
mains power is restored, the battery auto-recharges. This is a
design feature to ensure the delayed start thermostat clears
its memory at the end of every heating cycle.

What is Chronoproportional Control (TPI)?

A chronoproportional (or TPI) room thermostat makes boilers
operate more efficiently and provide close accurate control.
Chronoproportional control is a load compensator as it
ensures that the boiler ‘ON’ time is reduced to a minimum
and matches the boiler heat output with the heat loss. This

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reduces the net temperature of the return water to the
boiler. This is due to the TPI (Time Proportional and Integral)
advanced energy saving feature.

Rather than just a simple ON/OFF control, like other domestic
room thermostats, room thermostats with TPI increases
boiler efficiency by firing the boiler at regular intervals,
adjusting firing duration with demand, to maintain set
room temperatures, giving them a great advantage over
other domestic room thermostats and achieving a constant
ambient environment for the user e.g. if a property only has
a simple mechanical thermostat installed, then the energy
saving benefits of a replacement high efficiency condensing
boiler will not be realised as the boiler will rarely be running in
condensing mode.

Heating and hot water can account for over 80% of
total household energy usage. Chronoproportional (TPI)
thermostats can provide great cost savings. It can be used
on any boiler, with underfloor and radiator systems, zoned
heating and electric heating systems. The use of an electronic
thermostat with chronoproportional capability provides closer
temperature control plus possible reductions of 10% in both
fuel cost and carbon emissions. This thermostat has the
option of standard setting or TPI.

Setting the Temperature

To set the temperature, turn the dial until the desired
temperature is shown in the LCD display. The LCD display will
flash the desired temperature for (approximately) seconds
before returning to display the current room temperature.

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We are continuously developing our products to
bring you the very latest in energy saving technology
and simplicity. However, should you have any questions
setting up your controls please email us at
[e-mail] or for technical queries call
us on our dedicated technical helpline 07539 117468.

WARNING: Interference with sealed parts renders the
guarantee void.

In the interests of continuous product improvement we reserve
the right to alter designs, specifications and materials without
prior notice and cannot accept liability for errors.

Version 6.10.2

© ESi Controls Limited 2017