C
26 27
Zone
10K
0.4
2.0
3.6
Heating Curve
22
°
F
2
42
Dem
R
1
2
5
6
7
8
Pmp
Eight Stage Boiler Control 258
Dem
Heat
System
Pmp
9 10
28
Sen
Com
Sw
UnO
29 30
Sen
Sup Out
Power
Minimum
120
°
F
Off
170
Boiler
Differential
80
Power Supply: 24V 60Hz 5VA
Relay capacities: 24V 10A
Test
No power here
Maximum 24 volts
3
4
Stage
Sen
H1077
Date
S/N
221092
1234567
1
1
11 12
Stage
2
2
13 14
Stage
3
3
15 16
Stage
4
4
Power
Heat
Demand
Minimum
WWSD
Pump
Stage 1
Stage 2
Comb. Air
Stage 3
Stage 6
Stage 5
Stage 8
Stage 7
Stage 4
Menu
Item
Override
Setpoint
S
PRGM
TEMP
F C
Actual
Supply
Target
Supply
TIME
USE
AMPM
UNOCC
OVR
M T W T F S
OUTSIDE
ROOM
1
2
17 18 19 20 21 22 23
Air
Comb.
24 25
Stage
5
5
Stage
6
6
Stage
7
7
N/C
8
8
N/O
Com
M
tekmar
Zone
Control
Auto
Stage
1 2 3 4 5 6 7 8
Perm.
Demand
Ext. timer
Fixed last
Int. timer
Lo-Hi fire
Fixed lead
Off
1
2
3
4
5
6
7
8
9
External
Demand
Off
1
2
3
4
5
6
Stpnt
Reset
Rotate
8
- Data Brochure
Eight Stage Boiler Control 258
D 258
07/93
Terminal Plugs:
Power and out-
put connections
LEDs and
LCD screen;
display of times
& temperatures
Boiler
Differential
setting
Heating Curve
setting
Minimum
Supply setting
Terminal Plug:
Sensor and
timer inputs
Test button &
LED to test
main control
functions
System Pump
is on
Programming
buttons
Eight Stage Boiler Control 258
Power
Heat
Demand
Minimum
WWSD
Pump
Stage 1
Stage 2
Comb. air
Stage 3
Stage 6
Stage 5
Stage 8
Stage 7
Stage 4
Menu
Item
Override
Setpoint
Actual
Supply
Target
Supply
S
PRGM
TEMP
F C
TIME
USE
AMPM
UNOCC
OVR
M T W T F S
OUTSIDE
ROOM
1
2
Operating Mode
selector switches
Heating
is required
24Vac power
supply is on
Combustion air
damper is open
System is in
Warm Weather
Shut Down
Control is
maintaining
Minimum Supply
Input: Outdoor
Sensor 070
Included
Input: Supply
Sensor 071.
Included
Input:
Unoccupied
signal.
Optional
Input:
tekmar 10K
Zone Control
Optional
Output: Turn on stages #1 to #8
Output: Open
Combustion Air
Damper
Input: Heat Demand
signal.
Optional
Output: Turn
on System
Pump
24Vac power supply
Stages 1 to 8
are on
Outdoor Reset Strategy . . . . . . pg. 2
Error Messages . . . . . . . . . pg. 14
Sequence of Operation . . . . . . pg. 4
Programming . . . . . . . . . . . pg. 15
Installation . . . . . . . . . . . . . . . . . pg. 7
Pre-Programed Schedules pg. 18
Settings . . . . . . . . . . . . . . . . . . . pg. 10
Technical Data . . . . . . . . . . pg. 19
Testing . . . . . . . . . . . . . . . . . . . . pg. 13
Limited Warranty . . . . . . . . pg. 20
The tekmar Eight Stage Boiler Control 258 is a microprocessor-based control which
regulates the supply water temperature from up to 8 boilers based on the outdoor air
temperature, and optionally, the indoor air temperature through a tekmar 10K Zone
Control. The System pump is turned on when there is a Heat Demand and the outdoor
temperature is cool enough to require heat in the system. When a combustion air
damper is used, it must be opened before the first boiler is fired. The control has a
built-in setback timer and LCD screen to display temperatures and boiler running times.
