I Nstall Room Therm Ostat; Optional Outdoor Air Sensor ( Oas) - ECR International COMBI 115 Installation, Operation And Maintenance Manual

8 .5 I nst a ll Room Therm ost a t
I nst all room room t herm ost at on inside wall. Do not inst all
where it will be influenced by drafts, hot or cold water pipes,
lighting fixtures, television, sun rays or near a fireplace.
Dry contact only - do not apply 24 volts between 6 and 7.
A. Connect Room Therm ost a t
• turn power off to boiler;
• access t erm inal block M 2 ;
• connect room t herm ost at t o t erm inals 6 ( R) - 7 ( W ) -
8 ( C) ; Do not apply volt age bet ween 2 t erm inals. Dry
cont act only.
• t urn boiler power on;
• verify room t herm ost at operat es per room t herm ost at
m anufact urer inst ruct ions.
N OTE: m axim um load allowed is 10 m A
Dry cont act room t herm ost at s from various m anufact urers
can be at t ached t o boiler cont rol PCB.
8 .6 Opt iona l Out door Air Sensor ( OAS) Elect rica l
Connect ions
A. 1 K Ohm ( 1 K Ω) Optional Outdoor Air Sensor (OAS)
To connect t his accessory, see Figure 8- 5, t erm inals 4- 5, and
inst ruct ions supplied wit h
B. Set t ing " Kt " Clim a t e Curve
1.
Boiler aut om at ically recognizes OAS sensor when wired t o M2
t erm inal block. Display changes t o show current default " Kt "
value ( 80) . Not e display value.
2.
When operat ing in CH m ode, boiler set point is det erm ined
by t he Kt value select ed and act ual out side air t em perat ure.
Refer t o applicable ° F ( or ° C) chart , ( pg. 4 6 ) for set point
inform at ion.
3.
When OAS is inst alled, pressing
longer display boiler CH set point t em perat ure. I t now displays
Kt value, which can range from 10 t o 90.
• Select Kt range which will sat isfy t he desired boiler delivery
t em perat ure based on out door t em perat ure range expect ed
for your locat ion. For exam ple: if you need 176° F wat er
when t he out side t em perat ure is 20° F and colder, select 35
for your Kt set t ing.
• Rest rict t he upper lim it of t he Kt curve by using Param et er
P16 t o set t he m axim um boiler wat er t em perat ure. P16
Default is 176° F.
• To change" default " Kt value on boiler cont rol use
CH Heat ing but t ons.
4.
When scrolling has st opped, boiler will aut om at ically " SAVE"
value as new Kt default value and aut om at ically ret urn t o CH
m ode when no Kt adj ust m ent act ivit y is sensed. Kt values
can be changed in + / - 1 point increm ent s.
5.
To ret urn, t o verify or change current Kt " default value,
depress one of t he CH set point adj ust m ent but t ons ( once) ,
or , while in any heat ing or st andby m ode. Adj ust Kt
value t o obt ain desired com fort level.
8 - ELECTRI CAL CON N ECTI ON S
1 K Ω sensor.
or but t ons will no
FI GURE 8 - 4 Room Therm ost a t Connect ions
FI GURE 8 - 5 Out door Sensor Connect ions
1 K Ω
Sensors used for t his boiler are propriet ary t o
N o t e
t he m anufact urer. Use of aft er m arket sensors
will dim inish boiler perform ance.
or
4 5
A
Room End
Sw it ch
240013687 REV A [ 09/ 01/ 2022]