ESI ESRTD2 User manual

ESRTD2
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 Room Thermostat?
An explanation for householders 4
What is Chronoproportional Control (TPI)? 5
Setting the Temperature 6
Changing the Batteries 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 be
only one room thermostat to control the whole hosue (but
building regulations Part L require houses above a certain
What is a Digital Room
Thermostat?

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

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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) 5 seconds
before returning to display the current room temperature.
Changing the Batteries
To change the batteries, first disconnect the power then
loosen the screws and carefully remove the thermostat from
the backplate (removing the bottom part first and gently
pulling upwards). Change both batteries to high quality
AA/1.5V alkaline batteries. Never mix new and old batteries
together. Replace the thermostat on the backplate (fitting the
top part first and gently clicking into place) and tighten the
screws, then reconnect the power.

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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
[email protected].
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