background image

Page 34

Table 9.  Boiler Target Temperature

Reset Ratio

Outdoor T

emperature

 

8.C.4 

 Thermal Boost Function

8.C.4.a 

Outdoor Reset

To ensure that the heating system always satisfies a call for 

heat, the control is equipped with a thermal boost feature.  

If in Outdoor Reset Mode, the control will have a fixed 30 

minute Thermal Boost Interval. 

 

To set the desired warm weather shutdown 

temperature:  Press and hold the Mode button and 

simultaneously adjust the ECONOMY dial to the 

desired temperature setting. 

To turn warm weather shutdown of

f - which will allow 

space heating regardless of outdoor temperature - 

press and hold the Mode button and simultaneously 

turn the ECONOMY dial fully counter-clockwise. 

Release the Mode button. After doing this, be sure 

to reset the ECONOMY dial to the correct setting. 

Any time the outdoor temp exceeds the WWSD 

setpoint, the display will toggle boiler temperature (8 

seconds, outdoor temperature (2 seconds) and OFF 

(2 seconds).  Boiler will not fire for a call for heat 

until the outside temperature drops below the 

WWSD setpoint.

 

8.C.3  Adjusting Outdoor Reset 

Ratio

 

The outdoor reset will regulate the boiler’s 

temperature based on the temperature 

outside. On cold days, the boiler will run at 

higher temperatures to meet the heating 

load in the house. On warmer days, the 

boiler will run at lower temperatures to save 

energy while still meeting the heating needs 

of the house. 

 

The Outdoor Reset uses a reset ratio

 

method to control the boiler temperature. 

The reset ratio determines how much the 

boiler temperature is adjusted for changes 

in outdoor temperature. A reset ratio of 

2.0 means that for each 1 degree drop in 

outdoor temperature, the boiler temperature 

will increase 2 degrees. See Table 9. 

Outdoor Reset has a boost function based 

on a 30 minute time interval using a 10 

degree temperature boost.  You can check 

the current target temperature at any time, 

by pressing the Mode button in four short 

intervals. 
To set the desired outdoor Reset Ratio

1.    Locate the Outdoor Design Temperature 

on the left side of the chart (the coldest 

outdoor temperature at design load 

conditions).

2.    Locate the Boiler Target Temperature 

(the required supply water temperature 

at design load conditions) across from 

the Outdoor Design Temperature.

3.    Follow the column up to the top of the 

chart to obtain the Reset Ratio setting.

4.    Adjust the ECONOMY dial on the control 

to that Reset Ratio.

 

LAARS Heating Systems

Summary of Contents for MINI-THERM JX

Page 1: ...ment Installation and service must be performed by a qualified installer service agency or gas supplier AVERTISSEMENT Assurez vous de bien suivres les instructions donn es dans cette notice pour r dui...

Page 2: ...0 6 D Typical Plumbing Diagrams 21 SECTION 7 ELECTRICAL AND WIRING DIAGRAMS 7 A Safety Warnings 23 7 B Main Power 120V 15 Amp Circuit 23 7 C Outdoor Sensor 23 7 D Field Connections 24 7 D 1 TB1 Term B...

Page 3: ...System 36 9 B System Start Up Seq of Operation 36 9 C Proper Pilot Flame 38 9 D Lighting Instructions Decal 39 9 E System Shutdown 40 SECTION 10 MAINTENANCE 10 A Removing the Covers and Panels 40 10...

Page 4: ...justing high limit to anything other than 190 F 88 C Installing an outdoor sensor for the purpose of setting the Reset Curve Changing the temp readout from Fahrenheit to Celsius or back to Fahrenheit...

Page 5: ...ater use adjust the outlet control limit or use temperature limiting valves to obtain a maximum water temperature of 125 F 52 C WARNING The inlet gas pressure to the unit must not exceed 13 W C 3 2kPa...

Page 6: ...njury death or property damage Disconnect the power supply before beginning installation or changing the wiring to prevent electrical shock or damage to the equipment It may be necessary to turn o mor...

Page 7: ...Connections See 7 B on page 23 See 7 D on page 24 Gas Valve Pilot Ignitor Sensor Shown with front cover off Field Connections TB1 DHW Relay Connections TB3 Field Connections TB2 Low Loss Header Vent...

Page 8: ...nt cover and allow for advanced settings and installations that have outdoor reset and Low Water Cut Off LWCO with manual reset and several other advanced settings See SECTION 8 on page 30 Figure 4 Sy...

Page 9: ...4 Front View Draft Diverter Damper 6 15 3cm 3 1 4 8 3cm Low Loss Gas Supply Header A D B V 1 1 4 NPT Female OUT Supply IN Return 1 1 4 NPT Female 53cm 23cm F2 11 8cm 4 5 8 21 9 1 8 Max E Right View 1...

Page 10: ...Installation Clearances the minimum clearance between hot water pipes and combustible construction is 1 2 5 cm 2 A minimum of 15 381mm access must be available in front of the boiler for burner remov...

Page 11: ...es Improper venting of this appliance can result in excessive levels of carbon monoxide which can result in severe personal injury or death AVERTISSEMENT Cette chaudi re doit tre ventil conform ment a...

Page 12: ...openings one within 12 inches 305mm of the ceiling the other within 12 inches 305mm of the floor NOTE In Canada follow Canadian Standard CAN CSA B149 1 or local codes Outside Air Supply When combusti...

Page 13: ...p is designed so that it can be easily removed for normal boiler service and inspection without removal of the venting Avoid terminating boiler vents near air conditioning or air supply fans The fans...

Page 14: ...d expected system water temperatures Also ensure the boiler s anti condensing features are utilized by properly wiring the system pumps See Figure 28 on page 27 WARNING Do not store any chemical clean...

Page 15: ...c e d i s n i o t e c n a r a e l C G H Clearance to each side of centerline extended above meter regulator assy 3 ft 91 cm within a height of 15 ft 4 6 m m c 1 9 t f 3 t e l t u o t n e v r o t a l u...

Page 16: ...ANSI Z223 1 NFPA 54 AVERTISSEMENT Lorsqu une chaudi re existante est retir e d un syst me de ventilation commun le syst me de ventilation commun est susceptible d tre trop grand pour une ventilation a...

Page 17: ...ed gas meter Gas supply pressures to the heater are listed in Table 3 SECTION 4 Gas Connections 4 A Gas Supply and Piping Follow this guideline checklist for the gas supply installation 1 Gas piping i...

Page 18: ...e DO NOT ATTEMPT TO CONVERT THIS HEATER FOR USE WITH ANY OTHER TYPE OF FUEL AVERTISSEMENT Le unit est con u pour tre utilis avec du gaz naturel ou du gaz LP mais seulement des navires de l usine comme...

Page 19: ...eadloss See Table 5 Primary Secondary systems and boilers with LLH systems can be used to avoid needing larger system pumps Water Flow Requirements Electrical Data All Sizes with Low Loss Header witho...

Page 20: ...system utilizing oxygen permeable tubing Provide a water to water heat exchanger between systems to prevent corrosion of ferrous metals such as the boiler s piping wet walls etc Air elimination devic...

Page 21: ...es Indirect Tank Air Scoop Zone Pumps mustbesized properly Valves Check Valves DHW Pump Drains Drains Drains Drains Check Valve Valves Indirect Tank Check Valve Valves Indirect Tank DHW Pump DHW Pump...

Page 22: ...and 100 Low Loss Header is standard on models 125 150 and 200 and Optional for models 50 75 and 100 Figure 16 Low Loss Header with Zone Pumps and DHW Typical Plumbing Diagrams continued KEY PUMP CHECK...

Page 23: ...nly 7 A Safety Warnings NOTE All internal electrical components have been pre wired No attempt should be made to connect electrical wires to any other location except the terminal blocks and line volt...

Page 24: ...the optional DHW Relay Kit will control the boiler to the high limit setpoint See SECTION 8 for functionality 7 D 1 c Field Interlocks Field Interlocks allow for auxiliary limits or LWCO Breaking the...

Page 25: ...sation due to low inlet water temperature 7 D 2 c Aux Power This terminal and the 120V N terminal provide constant high voltage to accessories such as power vent combustion air and or zone relay syste...

Page 26: ...Air System Laars Power Vent Kit L1 N T1 T2 T3 L1 N T1 T2 T3 L N 1 2 4 Example Fields Controls CAS 4 Wiring to JX Combus on Air System Example Laars Power Vent Kit and Fields Controls CAS 4 Wiring to...

Page 27: ...d the total capacity of the transformers See Zone Valve manufacturer s installation instructions for valve electrical requirements Three Wire Zone Valves need an Isolation Relay if not using a zone co...

Page 28: ...4V L PILOT VALVE 24V L MAIN VALVE 24V N Y GAS VALVE S BLOCKED VENT SWITCH SWITCH ROLL OUT 24VAC 120VAC R O A A OAS COM W W SD X1 X2 X4 Y Y R R CONNECTOR DAMPER O Y Y R R R R TRANSFORMER BOILER PUMP CO...

Page 29: ...X1 2 X1 8 X1 5 MAIN VALVE 24V N 24V L 24V L SPARK IGNITOR GENERATOR SPARK J1 WATER TEMP SENSOR FACTORY INSTALLED X3 5 POWER VENTER PROOF OF FAN not supplied FACTORY JUMPERED VENT DAMPER PROOF OF OPEN...

Page 30: ...it to Celsius or back to Fahrenheit To change the economy settings 8 A 2 The HI LIMIT Dial Program Select The high limit is factory set at 190 F To adjust turn the HI TEMP dial until the desired setti...

Page 31: ...ctive IMPORTANT NOTE If the sensor installation has been modified to a single function sensor well this LED will not illuminate indicating that the control is not providing low water cut off functiona...

Page 32: ...proceed to Step 3 If you are using outdoor sensor and you ve programed your Reset Ratio then skip the Economy dial and proceed to Step 4 Always finish with Step 4 to ensure the high limit is properly...

Page 33: ...eset press and hold the Mode button The LED will illuminate solid red after 10 to 30 seconds but continue to hold the Mode button for 60 seconds and the LWCO will shut down the boiler and the LOW WATE...

Page 34: ...l regulate the boiler s temperature based on the temperature outside On cold days the boiler will run at higher temperatures to meet the heating load in the house On warmer days the boiler will run at...

Page 35: ...f the LOW WATER light is ng the control has been programmed to provide lock rotection in the event a low water condition is detected Manual Reset Low Water Cut Off ORTANT The system must be checked by...

Page 36: ...prevent air locked zones and boiler damage M START UP Carbon monoxide hazard The vent damper must be fully open and the flue must be clear before the main burner fires If the burner fires when the ve...

Page 37: ...he manual gas valve and verify that the burner flame is extinguished and the boiler continues to try to restart continuous retry of pilot You can then allow the boiler to restart by opening the manual...

Page 38: ...and the pilot should be adjusted down using the valve s pilot adjustment screw shown in Figure 42 If the flame is small and the inner cone does not engulf the pilot ignitor sensor then the pilot is u...

Page 39: ...ndie ou une explosion entra nant des dommages des blessures ou la mort A Cet appareil est muni d un dispositif d allumage qui allume automatiquement la veilleuse Ne tentez pas d allumer la veilleus ma...

Page 40: ...his panel off in normal operation High voltage and temperatures could cause a hazardous condition 10 A 1 Access Cover Removal To remove the front access cover simply turn the lock at the top center of...

Page 41: ...l 10 A 3 Side Panel Removal Remove the front access and the top as described previously Drain the boiler and remove the drain valve and or the PRV and associated fittings depending on the panel being...

Page 42: ...n 10 B Maintenance WARNING The Warranty does not cover damage caused by lack of required maintenance lack of water flow or improper operating practices AVERTISSEMENT La garantie ne couvre pas les domm...

Page 43: ...or power on any switch on the boiler 5 To perform voltage checks on 120VAC attach one meter lead to either terminal 2 or 3 of TB1 Use the other lead to check for power at any high voltage terminal or...

Page 44: ...efficiency Replace heat exchanger 6 Pump noisy Air in volute Bleed air from volute Check pump alignment Worn bearings Replace worn parts 7 Boiler pounding or knocking Water flow too low through boiler...

Page 45: ...ature drops to the automatically calculated Target Temp Differential Is the Green LED TEMP ACTIVE On The Control is Not Powered The Temp Active LED will be on at all times when the control is powered...

Page 46: ...VAC on the Gas Valve WARNING 11 D 2 Troubleshooting Flow Chart 2 burners on from previous page Is There 24 VAC on the PV terminal of the Valve If Flame Light is solid spark should be off and 24VAC sho...

Page 47: ...and system piping is simplified Primary Secondary Piping Two or more interconnecting circulating loops each with its own pump Primary Boiler Circuit Secondary System Circuit Reverse Return Piping Bal...

Page 48: ...X 5 R 3 4 0 3 X 5 R e d i S A3 Panel 8 3 0 3 X 0 2 8 3 0 3 X 5 1 8 3 0 3 X 2 1 8 3 0 3 X 0 1 8 3 0 3 X 7 8 3 0 3 X 5 t n o r F A4 Front 5 4 0 3 X 0 2 R 5 4 0 3 X 5 1 R 5 4 0 3 X 2 1 R 5 4 0 3 X 0 1 R...

Page 49: ...Page 49 C2 A7 A2 A9 A1 A8 A10 A3 A4 A12 A13 A14 D3 B2 B4 B5 C6 C3 B6 D13 D2 B8 B9 A15 D1 A6 A5 A16 A17 B1 B7 C1 D4 C5 C4 B4 B3 MINI THERM JX Residential Boilers...

Page 50: ...L0039000 L0039000 L0039000 L0039000 2001 5000 L0032900 L0032900 L0032900 L0032900 L0032900 L0032900 5001 8000 L0032800 L0032800 L0032800 L0032800 L0032800 L0032800 8001 10000 L0032700 L0032700 L00327...

Page 51: ...2 not shown 1 H2413100 INSTRUCTIONS INSTALLATION DHW RELAY KIT JX n 1 5X7002 DHW PANEL ASSY JX ECN DECIMALS XX DRAFT CHECK RELEASE REVISIONS K REV CF 6JUL20 DWG CHANGE IN WRITING BY LAARS HEATING SYST...

Page 52: ...6 Fax 800 559 1583 Headquarters 20 Industrial Way Rochester NH USA 03867 603 335 6300 Fax 603 335 3355 9 Brigden Gate Halton Hills Ontario Canada L7G 0A3 905 203 0600 Fax 905 636 0666 www Laars com Li...

Reviews: