Watts tekmar 294 - Boiler Operation - Basics; Boiler Availability and Configuration; Boiler Type and Mass Settings; Modulation and Fire Control

40
IOM-T-294 2205 © 2022 tekmar
The 294 can operate four boilers and up to 16 boilers when used
together with the three Smart Boiler Expansion 294EXP. Each
boiler is configured individually to provide maximum flexibility.
Boiler Available
Select the boiler available to On to allow the boiler to be part of
the staging sequence. Select Off if the boiler is being serviced
or that boiler output is not used.
Boiler Manufacturer, Series and Model
The 294 includes presets for over 1600 boiler models. Select
the manufacturer, series and then the model and the control
loads the recommended presets for that specific boiler. The
boiler settings can be changed if desired.
If the manufacturer, series or model of your boiler is not avail-
able, then set the Boiler Manufacturer to Custom.
tekmar is continually updating the supported boilers presets
which is automatically updated when the 294 is connected to
the Internet. It is recommended to connect the control to the
Internet first if your boiler model is not available when first
powered on.
Boiler Fuel
Select the type of fuel used by the boiler.
Boiler Type
When configuring a Custom boiler, the Boiler Type offers six
different options to choose from:
1-Stage
This setting operates a one-stage boiler and is available in all
configurations. The Boiler Status displays 100% when the
boiler is on and 0% when the boiler is off.
2-Stage
This setting operates a two-stage boiler and requires the next
boiler output to be not configured. In addition, the 2-stages
must be all on the same 294 or 294EXP and cannot span to
another 294EXP.
Example: If boiler 1 is set to 2-stage, then boiler enable 1 and
boiler enable 2 are used.
The Boiler Status displays 50% when stage 1 is on, 100%
when stage 2 is on and 0% when the boiler is off.
3-Stage
This setting operates a three-stage boiler and requires the
next two boiler outputs to be not configured. In addition, the
3-stages must be all on the same 294 or 294EXP and cannot
span to another 294EXP.
Example: If boiler 1 is set to 3-stage, then boiler enable 1, 2
and 3 are used.
The Boiler Status displays 33% when stage 1 is on, 66% when
stage 2 is on, 100% when stage 3 is on and 0% when the
boiler is off.
4-Stage
This operates a four-stage boiler and requires the next three
boiler outputs to be not configured. In addition, the 4-stages
must be all on the same 294 or 294EXP and cannot span to
another 294EXP.
Example: If boiler 1 is set to 4-stage, then boiler enables 1, 2,
3 and 4 are used.
The Boiler Status displays 25% when stage 1 is on, 50% when
stage 2 is on, 75% when stage 3 is on, 100% when stage 4 is
on, and 0% when the boiler is off.
Modulating Target Temp
The modulating output operates a boiler that interprets an
analog input signal as a target temperature. The Output
EMS Signal Minimum sets the starting voltage. The EMS
Temperature Minimum sets the starting target temperature.
The EMS Temperature Maximum sets the maximum target
temperature.
The Boiler Status displays the boiler target temperature when
the boiler is on and displays "- - -" when the boiler is off.
Modulating Fire Rate
The modulating output operates a modulating boiler by con-
trolling the burner firing rate. The Boiler Enable relay is also
used to give a boiler enable to allow the modulating boiler to
go through the ignition sequence. The boiler enable relay may
not be necessary. Please consult the boiler manual to wiring
information.
The Boiler Status displays the boiler firing rate when modulating
the boiler from 0 to 100% output.
Modulation Type
Select the modulating output to be either 0-10 V (dc) or 4-20
mA. A 4-20 mA output can be converted to a 0 - 135 Ω out-
put using a 0 - 135 Ω Converter 005.
Fire Delay
The Fire Delay is the ignition delay time of the boiler, from when
the boiler enable contact is closed until when a flame is estab-
lished. The Fire Delay can be found in the boiler manual or can
be timed with a watch.
Modulation Delay
After the flame is established, some boilers require the firing
rate to hold at low fire before the firing rate can change. Set
this time as the Modulation Delay.
Boiler Mass
The Boiler Mass setting selects the thermal mass characteristics
of each boiler. Operation of the boiler can become unstable if the
incorrect Boiler Mass setting is chosen. A key sign of unstable
boiler operation is that the flame will continue to increase and
then decrease in short periods of time.
Low
Select Low mass for smaller sized boilers. This provides short
pre and post purge times for the pumps, modulates the boiler
firing rate at a slow rate, and operates the boiler staging with
shorter inter-stage delays.
Medium
Select Medium mass for medium sized boilers. This provides
moderate pre and post purge times for the pumps, modulates
the boiler firing rate at a moderate rate, and operates the boiler
staging with moderate inter-stage delays.
Boiler Operation