Lochinvar RLY30086 User Manual

Specialties and accessories

The Smart System™ Multi Temperature Loop Control
(MTLC) is designed to simplify the integration of KNIGHT
Heating Boilers into multiple temperature hydronic
heating systems, and control up to three separate

hydronic heating loop temperatures, while maximizing
the effi ciency of the heating boiler system as a primary
function. The new MTLC works in conjunction with the

on-board SMART SYSTEM Contol on all fl oor-standing
and wall-mount KNIGHT Heating Boilers (KBN081-286,
WBN051-211, WHN055-399) for residential applications
as well as KNIGHT XL (KBN400-801) Commercial Heating
Boilers.

Heating comfort and energy-effi cient boiler operation
are the driving forces behind the MTLC. Many of today’s
hydronic heating systems are complex in that they
distribute heat to as many as three different supply loops
plus an indirect water heater, all requiring a unique
temperature. MTLC takes the guesswork out of how to
control the boiler supply water temperature without
sacrifi cing effi ciency of the heating boiler system.

The Smart System™
Multi Temperature Loop Control

FEATURES

Control up to three separate hydronic heating loop
temperatures.

Outdoor reset control of up to three hydronic heating
loop temperatures.

On/Off control of up to three hydronic heating loop pumps.

Control of up to three 24 VAC mixing valves

Loop temperature feedback from up to three hydronic
heating loops (Sensors are standard equipment).

“Under the cover”, the Smart System MTLC utilizes

a microprocessor based control board to control up

to 3 different hydronic heating loop temperatures

while maximizing the boiler system effi ciency.

Lochinvar.com

Smart System™ Multi Temperature Loop Control

How It Works

LOOP 3 LOOP 2 LOOP 1

C

M

24VAC Mixing

Valve Two

SYSTEM PUMP

TWO

H

4

Hydraulic Separator/

Buffer Tank

SYSTEM PUMP

THREE

Mix Mix

C

H

M

24VAC Mixing

Valve Three

The Smart System™ Multi Temperature Loop Control (MTLC)

1

communicates with Knight, KnightXL and Knight Wall Mount
boilers through the cascade connection on the boiler’s low

Mix

C

M

24VAC Mixing

Valve One

3

120VAC

Output to

Pumps

2

SYSTEM PUMP

ONE

H

voltage connection board. The MTLC has its own individual
cascade address so there is no need to assign an address
through on-screen programming.

As a heat demand is initiated, the associated loop pump

2

will be enabled and begin to circulate water.

*

24VAC

to Mixing

Valves

1

120VAC In

*Primary/secondary piping is also acceptable.

3

4

MTL-01

A loop temperature sensor will communicate the actual loop water temperature with the Multi Temperature
Loop Control. Each loop temperature will be displayed on the boiler’s user interface panel.

The MTLC will actuate the three way valve via a 24 VAC signal to meet the required setpoint

. As space heating

water temperature approaches setpoint, the MTLC will actuate the three way valve to keep the loop temperature
within the programmed range. Indicator lights on the MTLC will display cascade communication with the boiler,
pump status and three way valve activity.

Model
Number Kit Contents

RLY30086 Multi Temp Loop Control Board with Installation Accessories
Wall Mount Installation Hardware, 3 Loop Temperature Sensors,
and Instruction Booklet

Electrical Requirements

Supply Voltage 120 VAC
Pump Output 120 VAC (5A Max)
Mixing Valve Output 24 VAC *(Floating Signal)
Sensor NTC Thermister 10K

Lochinvar, LLC • Maddox Simpson Pkwy • Lebanon, TN 37090 • 615-889-8900 / Fax: [phone]

www.Lochinvar.com

PDP-5M-11/11–Printed in U.S.A.