Taco SR506-5 User manual

102-571
SUPERSEDES: New Plant ID # 9300-4099 EFFECTIVE:February 17,2021
For information on Taco’s Switching Relays (SR) including catalog sheet, instruction sheets, Visio stencils
and our highly praised Zone Controls Wiring Guide, scan the QR code to the left or go
to our website:
www.TacoComfort.com.
Overview:
The SR506-5 is a six zone switching relay that can have up to 6 thermostats
connected and will operate up to 6 zone circulators, plus 2 auxiliary outputs (AUX) to
control circulators; like boiler and primary loops.
The SR506-5 has a priority zone option, allowing zone 1 to operate and deactivate
zones 2 through 6 during a priority call; this is ideal for when using an indirect water
heater.
The SR506-5 includes timing options for Post Purge, Pump Exercise and Priority
Protection. The SR506-5 includes an energy saving program that can adjust the
temperature of a modulating-condensing boiler or conventual On/Off boiler to
increase the comfort level and use less fuel, without the need to install an outdoor
sensor.
Table of Contents
1. Warnings & Safety Information
2. Location & Installation
3. Operation & Dip Switch Settings
4. Wiring Procedure
5. Product & Applications Diagrams
6. Reset Control Setup & Wiring
7. The Taco eLink mobile app
8. Troubleshooting & FAQ’s
9. Inner Cover Removal & Fuses
10. Specifications
11. Accessories & Replacement Parts
12. Warranty

1. Warnings & Safety Information:
FCC Regulatory Statements
This device complies with Part 15 of the FCC Rules. Operation is subject to the following two conditions:
(1) This device may not cause harmful interference.
(2) This device must accept any interference received, including interference that may cause undesired operation.
This equipment has been tested and found to comply with the limits for a Class B digital device, pursuant to part 15 of the Federal
Communication Commission (FCC) rules. These limits are designed to provide reasonable protection against harmful interference in a
residential installation. This equipment generates, uses and can radiate radio frequency energy and, if not installed and used in accordance
with the instructions, may cause harmful interference to radio communications. However, there is no guarantee that interference will not
occur in a particular installation. If this equipment causes harmful interference to radio or television reception, which can be determined by
turning the equipment off and on, the user is encouraged to try to correct the interference by doing one or more of the following measures:
•Reorient or relocate the receiving antenna.
•Increase the separation between the equipment and receiver.
•Connect the equipment into an outlet on a circuit different from that to which the receiver is connected.
•Consult the dealer or an experienced radio/TV technician for help.
NOTE: THE GRANTEE IS NOT RESPONSIBLE FOR ANY CHANGES OR MODIFICATIONS NOT EXPRESSLY APPROVED BY THE PARTY RESPONSIBLE
FOR COMPLIANCE. SUCH MODIFICATIONS COULD VOID THE USER’S AUTHORITY TO OPERATE THE EQUIPMENT.
RF Exposure Warning
This equipment complies with FCC radiation exposure limits set forth for an uncontrolled environment. In order to avoid the possibility of
exceeding the FCC radio frequency exposure limits, human proximity to the antenna shall not be less than 20 cm during normal operation
and must not be co-located or operating in conjunction with any other antenna or transmitter.
ISED Regulatory StatementsThis device complies with ISED Canada license-exempt RSS standard(s). Operation is subject to the following two
conditions: (1) this device may not cause interference, and (2) this device must accept any interference, including interference that may
cause undesired operation of the device.
Le présent appareil est conforme avec ISED Canada applicables aux appareils radio exempts de licence. L'exploitation est autorisée aux deux
conditions suivantes: (1) l'appareil ne doit pas produire de brouillage, et (2) l'utilisateur de l'appareil doit accepter tout brouillage
radioélectrique subi, même si le brouillage est susceptible d'en compromettre le fonctionnement.
CAN ICES-3 (B)/NMB-3(B)
RF Exposure Information
This equipment complies with ISED RSS-102 radiation exposure limits set forth for an uncontrolled environment. This transmitter must be
installed to provide a separation distance of at least 20 cm from all persons and must not be co-located or operating in conjunction with any
other antenna or transmitter.
Cet équipement est conforme avec ISED RSS-102 des limites d'exposition aux rayonnements définies pour un environnement non contrôlé.
Cet émetteur doit être installé à au moins 20 cm de toute personne et ne doit pas être colocalisé ou fonctionner en association avec une
autre antenne ou émetteur.
WARNING: Wiring connections must be made in accordance with all applicable electrical codes. Use copper wire only. 120 VAC wiring must
have a minimum temperature rating of 75°C. Failure to follow this instruction can result in personal injury or death and/or property
damage. Based on current draw; 12-18 gauge wire recommended for 120 VAC connections, 14-22 gauge wire for thermostat
connections, and 14-22 gauge wire for 24 VAC source connections.

2. Location & Installation:
Planning:
Included in Package:
SR506-5 switching relay; six zone
2 Spare fuses attached to inner cover
Instruction sheet
Strap-on temperature sensor
Tools & Material Needed:
Small straight blade screwdriver
Phillips screwdriver
Torpedo level
Wire strippers
Screws or hardware for mounting
Electrical connectors for field wiring
Low and live voltage wiring (per code)
Location: Do not mount to a surface that exceeds 104°F (40°C). The unit must be only located in dry
interior locations. Use only copper conductor supply wire suitable for at least 105° C. All circuits
must have a common disconnect and be connected to the same pole of the disconnect. Product is
not suitable for installation in hazardous locations.
Installation:
1. Hang the panel on awall with one mounting screw.
2. Levelthepanel.
3. Install other 3 mounting screws

3. Operation & Dip Switch Settings:
General Operation:
When any thermostat calls for heat,
the appropriate circulating pump is energized, the red light goes on and the
boiler end switch relay and AUX circulator relay(s) are energized.
Expansion Connections: Set dip switch (#1) to MASTER on the switching relay
that is designated as the priority zone control. Set all other daisy chained zone
controls to EXPANSION.
Using thermostat wire (18-22 gauge) connect between
terminals 1, 2, 3 on the master control to the corresponding 1, 2, 3 on the
expansion
zone control(s). Zone controls may be daisy chained up to 20 Taco
zoning panels using
any combination of SR and ZVC controls (120 zones if all
are 6 zone panels).
Priority Operation: When the priority dip switch (#2) is set to ON and the priority
zone (zone 1) is actuated, all other zones will stop operation until priority zone
is satisfied. When not switched to priority, all zones will
operate independently.
More adjustments are available when using the eLink mobile app.
Priority Protection Operation: If the priority zone calls continuously for more
than one hour, power
is returned to all the other zones, allowing each zone to
function independently. Once the priority zone is satisfied, the control's auto-
reset is
activated, and the priority zone is again allowed to have priority for up to
one hour starting from when it calls next.
Primary Pump Operation: When the dip switch (#3) is set to OFF, the primary
circulating pump output will energize when any zone calls for heat,
except the
priority zone. When the dip switch is set to ON, the primary circulating pump
output will energize when any zone calls for heat.
Post Purge Operation: When the dip switch (#4) is set to ON, the priority
zone output will stay energized for 2 minutes after its thermostat or aquastat is
satisfied, but not operate the boiler. More adjustments are available when using the eLink mobile
app.
Pump Exercise Operation: When the dip switch (#5) is set to ON, the solid state timer cycles all the
circulating pumps that are attached to the
Switching Relay to run for 30 seconds every 2
weeks. More adjustments are available when using the eLink mobile app.
Low Limit (ZC) Operation: When the dip switch (#6) is set to ON and the boiler drops below the
set low limit (terminal ZC connected to boiler), all zone circulating pumps will stop. When the boiler
rises above the
set low limit, the zone circulating pumps are allowed to operate.
AUX 1; ZR /Circulator Output: The AUX 1 output is energized when any zone calls for heat.
More adjustments are available when using the eLink mobile app.
AUX 2; Primary Circulator Output: The AUX 2 output follows dip switch setting # 3 listed above.
More adjustments are available when using the eLink mobile app.
SmartPlus
®
Recirc Logic: SmartPlus adds intelligence to your system by learning when hot water is
used in the home. The pipe-mounted sensor records daily hot water usage patterns during the
course of the week. Recorded data is used to automatically run the circulator at the same times the
following week. So hot water is always available when it is needed. If usage pattern changes, the
SmartPlus adjusts automatically.
“Smart” Mode (default mode): the SmartPlus logic will run in Pulse mode as described below
for the first 7 days of operation. During the first 7 days, the SmartPlus logic monitors and
records the home's hot water usage pattern. For the following 7 days, the SmartPlus logic will
use the preceding week's usage pattern to cycle the pump during the recorded hot water usage
times. This process of recording and repeating is continuous, and automatically adjusts the
pump "ON" times to match the house hold's usage pattern.
“Pulse” Mode: When set to Pulse mode, the SmartPlus logic will cycle the circulator pump "ON"
for 5 minutes, then “OFF” for 10 minutes to maintain hot water at all faucets and taps. It will
repeat the cycle continuously.
More adjustments are available when using the eLink mobile
app.
When a sensor is connected to the Recirc sensor input, zone 2 output will now be designated for
recirculation of DHW loop and activated based on DHW usage.

4. Wiring Procedure:
End Switches (Low Voltage Dry Contacts):
Main
The main end switch closes when any zone thermostat calls for heat and
connects to T-T on boiler operating control.
Priority The priority end switch closes only when the priority zone thermostat
or aquastat is calling for heat and connects to DHW T-T on boiler (optional).
Thermostat Input (24 vac):
R Hot side of transformer. Connect to R on thermostat.
W Switched R signal from thermostat. Connect to W on thermostat.
C Common side of transformer. Connect to COM on thermostat (optional).
Expansion Connections: (optional)
1 Connect 1 on Master zone control to 1 on all Expansion zone control(s).
2 Connect 2 on Master zone control to 2 on all Expansion zone control(s).
3 Connect 3 on Master zone control to 3 on all Expansion zone control(s).
Power Input (120 vac):
H Connect to 120 vac Hot side of power supply to zone control.
N Connect to 120 vac Neutral side of power supply to zone control.
G Connect ground wire to ground screws on base of zone control.
Circulator Output; Zones 1-6 (120 vac):
H Connect the Hot output to Hot power input on circulator.
N Connect the Neutral output to Neutral power input on circulator.
G Connect ground wire to ground screws on base of zone control.
Circulator Output; ZR / AUX 1 (120 vac):
H Connect the Hot output to Hot power input on circulator (or to ZR; see below ).
N Connect the Neutral output to Neutral power input on circulator.
G Connect ground wire to ground screws on base of zone control.
Circulator Output; Primary / AUX 2 (120 vac):
H Connect the Hot output to Hot power input on circulator.
N Connect the Neutral output to Neutral power input on circulator.
G Connect ground wire to ground screws on base of zone control.
Low Limit Aquastat / Tankless Coil Application (120 vac):
ZR - H Connect the Hot ZR (AUX 1) output to ZR input on boiler’s operating control.
ZR -
N Neutral (optional).
ZC - H Connect the ZC input to ZC (Hot) output on boiler’s operating control.
ZC - N Connect (optional).
SmartPlus Recirc Logic Sensor
- Mount the strap-on sensor on domestic hot water supply pipe on water heater using wire tie or pipe
clamp and insulate sensor with pipe insulation.
-
Connect the strap-on sensor to the two terminals labeled Recirc Sensor on switching relay.
Dedicated Return Line HotLink Valve or Crossover Style Valve
Conceptual Sketches Only, refer to individual manufacture’s installation instructions for additional details. Local codes shall prevail.
For more information on
hot water recirculation
scan QR code
P OW E R IN
120 V AC
N H
(P RIORITY)
ZONE 1
N H N H
ZONE 2
N H
ZONE 3
120 V AC
ZONE IN
NZC
(AUX 1)
Z R
N H
(AUX 2)
PRI MAR Y
N H
EXPANSION
P 1 2 3
PR IORIT Y
BO I L ER
END
S W ITC H
M AIN
BO I L E R
END
S W ITC H
T STAT 1 T STAT 2
(PR IOR IT Y)
T STAT 3
R W C R W C R W C

5. Product & Applications Diagrams:
PA01-C - SR506-5 with 5 Zone Circulators & Indirect DHW; Supply & Return Headers
Mechanical Diagram
Electrical Diagram
Dip Switch Settings
1. OFF - Master
2. ON - Priority
3. OFF - Primary Pump
4. OFF or ON - Post Purge
5. OFF or ON - Pump Exercise
6. OFF - ZC Low Limit
Conceptual Sketches Only, refer to individual
manufacture’s installation instructions for additional
d t il L l d h ll il

PA02-C - SR506-5 with 5 Zone Circulators & Indirect DHW; Primary/Secondary
Mechanical Diagram
Electrical Diagram
Dip Switch Settings
1. OFF - Master
2. ON - Priority
3. OFF - Primary Pump
4. OFF or ON - Post Purge
5. OFF or ON - Pump Exercise
6. OFF - ZC Low Limit
Conceptual Sketches Only, refer to individual manufacture’s
installation instructions for additional details. Local codes
h ll il

Dip Switch Settings; Master
1. OFF -Master
2. ON -Priority
3. OFF -Primary Pump
4. OFF or ON -Post Purge
5. OFF or ON -P ump Exercise
6. OFF -ZC LowLimit
Dip Switch Settings;
Expansion
1. ON -Expansion
2. OFF -Priority
3. OFF -Primary Pump
4. OFF or ON -Post Purge
5. OFF or ON -P ump Exercise
6. OFF -ZC LowLimit
PA03-C –High & Low Temp Temperature Zones & Indirect DHW; Primary/Secondary
Mechanical Diagram
Electrical Diagram
Conceptual
Sketches Only,
refer to individual
manufacture’s
installation
instructions for
additional details.
Local codes shall
prevail.

PA04-C – Oil Fired Boiler with Tankless Coil; Supply & Return Headers
Mechanical Diagram
Electrical Diagram
Dip Switch Settings
1. OFF -Master
2. OFF -Priority
3. OFF -Primary Pump
4. OFF or ON -Post Purge
5. OFF or ON -P ump Exercise
6. ON -ZC Low Limit
SAFETY NOTICE
TWO SEPARATE sources of power may be connected to an oil boiler’s aquastat control.
Before servicing an oil fired boiler make sure the service switch is off. Then confirm that a secondary source of power does not exist to the boiler’s
aquastat control. Failure to fix the problem could result in boiler being activated when zone calls for heat, that could result in serious injury or death.
Conceptual
Sketches Only,
refer to individual
manufacture’s
installation
instructions for
additional details.
Local codes shall
prevail.

6. Reset Control Setup & Wiring (Optional)
Boiler Reset Types: The ZVC406-5 includes two types of boiler reset control logic:
Indoor Reset Control (Load Reset) uses the thermostat cycling information to determine the
supply water temperature. Thermostat short cycling usually indicates supply water
temperature is too high. Long on cycles usually indicates supply water temperature is too low.
Outdoor Reset Control uses an outdoor sensor to compare it against the reset ratio
(configured by installer) to determine the appropriate supply water temperature.
General Operation: When any thermostat calls for heat, the appropriate zone valve is
energized, and the yellow light goes on. When the zone valve is fully open, the red light goes
on and energizes the circulator relay(s). The boiler end switch relay and modulating output will
be controlled by the reset algorithm. either based on indoor thermostat operation or on
outdoor temperature.
Control Setup: The Taco eLink mobile app is required to set type of reset control and
parameters to operate. See section 7 for more information on the Taco eLink mobile app.
Wiring of Reset Control:
Remove the inner cover as shown in section 10, page Xof this manual to have access to wire.
Sensor Connections:
Boiler Sensor: A boiler supply sensor is required for either indoor or outdoor reset.
Wire the supplied strap-on sensor to the Boiler Sensor terminal block.
Outdoor Sensor: An outdoor sensor is required when utilizing the outdoor reset
function. Connect Taco sensor P# 9300-2052RP to Outdoor Sensor
terminal block and mount on north side of building.
Boiler Connections:
Modulating Output: Most Mod-Con boilers have and input for an external modulating
signal (0-10 vdc or 4-20 ma) to control boiler. Connect the
modulating output to appropriate input terminals on boiler; noting
that the polarity is correct. Some Mod-Con boilers also require a T T
call for heat to activate boiler. In this case, wire the Main Boiler End
Switch to T T input on boiler.
Dry Contact End Switch: ON/OFF boilers are controlled by the Main Boiler End Switch on
zone control. Wire the Main Boiler End Switch to T T input on boiler.

7. The Taco eLink Mobile App (Optional)
Note: The Taco eLink mobile app is not required for standard
installations.
Advanced Control & Monitoring Options: The Taco eLink mobile app is
required for advanced control functions and parameters to operate.
Search for Taco eLink within the App Store or Google Play on your mobile
device to download the mobile app.
iOS Android OS
Follow the app menu to configure advanced features that the Taco new zone
controls have to offer, including;
Different levels of access
Zone naming
Programmable output naming
Alerts & messages
Post purge time delay adjustment
Pump exercise time delay adjustment
Priority protection time delay adjustment
Indoor boiler reset
Outdoor boiler reset
SmartPlus® DHW recirculation logic
AUX 1 output behavior
AUX 2 output behavior
AUX 3 output behavior
Cooling function
Zone association

The eLink APP

The eLink APP

8. Trouble Shooting & FAQ’s
For your convenience, the Taco Tech Support team is available anytime 24/7. Just call 401-
942-8000 for help.
Problem: Digital thermostats do not work correctly when connected to a switching relay.
Solution: Some thermostats are a “Power Stealing” type which means they are powered by the
switching relay with just 2 wires (
R & W ). A resistor may be needed in order to have the thermostat
work properly.
This resistor should be placed between the W & C ( common ) terminals of the
switching relay. If the thermostat manufacturer does not
supply a resistor, a 1000 ohm ½ watt
resistor has proven to work with most.
Problem: No heat in a zone or room of building.
Solution: LED diagnostic lights will help find a component that is not working properly. The
green LED should always be on, indicating
that power is connected, and the solid-state fuse is
good. When there is a call for heat, the red LED will come on indicating power to the zone
circulator. This indicates the thermostat is working correctly. If the red LED does not come
on, then check the thermostat and thermostat wiring for errors.
Problem:
Solution
9. Inner Cover Removal & Fuses:
1. Gently push in tab in with finger on side of inner cover.
2. Lift cover and hinge up to remove it.
3. Fuses are replaceable; with 2 spare fuses attached to inner cover near transformer.

10. Specifications:
Power and Electrical Ratings:
Power Supply: 120VAC ±10%, 60Hz, 20A
Zone Pump Output Rating:
120 Vac, 1/6 HP
AUX(s) Pump Output Rating:
120 Vac, 1/6 HP
Boiler End Switch Contact Rating:
24 Vac, 1A,
Boiler Modulating Output Rating:
0-10 VDC Mode; 500 Ω min impedance
4-20 mA Mode; 1k Ω max impedance
Expansion Terminals:Low voltage, 3-wire
polarity-sensitive, digital communications that
links other Switching Relays (SR-5), Zone Valve
Controls (ZVC-5) and other Modbus equipment.
Electrical Terminals (Line Voltage):
Wire Range Min / Max: 12-24AWG
Torque: 7.0 lbs-in. Max.
Electrical Terminals (Low Voltage):
Wire Range Min / Max: 12-28AWG
Torque: 3.5 lbs-in. Max.
Transformer Rating:
40 VA, 24 Vac Class II
ZC Input Rating:
120 VAC
Environmental Ratings:
Ambient Temperature Rating:
32°F to 104°F (0°C to 40°C)
Operating Humidity Range (% RH):
5 to 90% RH, noncondensing
Sensor Temperature Rating:
-58°F to 230°F (-50°C to110°C)
DIP Switch Timing Settings:
Post Purge: 30 seconds; adjustable with
mobile app.
Pump Exercise: 30 seconds per 2 weeks of
space heating inactivity; adjustable with
mobile app.
Thermostat Compatibility: Compatible with
most mechanical, battery operated,
power-stealing (power-robbing),
hardwired and “Smart” thermostats.
Temperature Sensor: 10K ohm NTC
thermistor at 77°F (25°C) ± 0.5°F (±0.3°C).
Lead length: ?ft. (m); up to 500 ft. (150 m)
using 18 AWG or larger wire, beta=3892.
Dimensions (HxWxD): 15.6 x 8.7 x 2.7 in.
(39.5 x 22.0 x 6.8 cm) approximate
Weight: lb. (kg)
Approvals: UL, FCC,
11. Accessories & Replacement Parts
Item Part Number
Strap-on sensor for boiler reset control or SmartPlus logic ------------------ 9300-2044RP
Outdoor sensor for outdoor boiler reset and smart pump exercise ------- 9300-2052RP
Circulator output fuses; slow blow, 6 amp, 2AG (5mm X 15mm) ----------- SR6A-001RP
Low voltage fuses; slow blow, ? amp, 2AG (5mm X 15mm) ------------------ ?
Transformer; 40 VA at 24 VAC with connectors to plug into board -------- 9300-4107RP

12. LIMITED WARRANTY STATEMENT
Taco, Inc. will repair or replace without charge (at
the company’s option) any product or part which is
proven defective under normal use within three (3)
years from the date of start-up or three (3) years
and six (6) months from date of shipment
(whichever occurs first) Need date code wording…
In order to obtain service under this warranty, it is
the responsibility of the purchaser to promptly
notify the local Taco stocking distributor or Taco in
writing and promptly deliver the subject product or
part, delivery prepaid, to the stocking distributor.
For assistance on warranty returns, the purchaser
may either contact the local Taco stocking
distributor or Taco. If the subject product or part
contains no defect as covered in this warranty, the
purchaser will be billed for parts and labor charges
in effect at time of factory examination and repair.
Any Taco product or part not installed or operated
in conformity with Taco instructions or which has
been subject to misuse, misapplication, the
addition of petroleum-based fluids or certain
chemical additives to the systems, or other abuse,
will not be covered by this warranty.
If in doubt as to whether a particular substance is
suitable for use with a Taco product or part, or for
any application restrictions, consult the applicable
Taco instruction sheets or contact Taco at
[401-942-8000].
Taco reserves the right to provide replacement
products and parts which are substantially simi- lar
in design and functionally equivalent to the
defective product or part. Taco reserves the right to
make changes in details of design, construction, or
arrangement of materials of its products without
notification.
TACO OFFERS THIS WARRANTY IN LIEU OF ALL
OTHER EXPRESS WARRANTIES. ANY WARRANTY
IMPLIED BY LAW INCLUDING WARRANTIES OF
MERCHANTABILITY OR FITNESS IS IN EFFECT ONLY
FOR THE DURATION OF THE EXPRESS WARRANTY
SET FORTH IN THE FIRST PARAGRAPH ABOVE.
THE ABOVE WARRANTIES ARE IN LIEU OF ALL
OTHER WARRANTIES, EXPRESS OR STATU- TORY,
OR ANY OTHER WARRANTY OBLIGA- TION ON THE
PART OF TACO.
TACO WILL NOT BE LIABLE FOR ANY SPECIAL,
INCIDENTAL, INDIRECT OR CONSEQUENTIAL
DAMAGES RESULTING FROM THE USE OF ITS
PRODUCTS OR ANY INCIDENTAL COSTS OF
REMOVING OR REPLACING DEFECTIVE PRODUCTS.
This warranty gives the purchaser specific rights,
and the purchaser may have other rights which
vary from state to state. Some states do not allow
limitations on how long an implied warranty lasts or
on the exclusion of incidental or consequential
damages, so these limitations or exclusions may not
apply to you.