Lochinvar 1 service manual Test low water flow conditions, Test procedure

2 Maintenance

Test low water flow conditions

NOTICE	This test is to be carried out once the
	SYNC boiler is completely piped in
	with adequate gas and water flow.
	Once the test is completed, ensure
	that the isolation valve is opened up to
	allow full water flow.

Test procedure

1.Set the SYNC to operate with the demand configuration parameter set to 1 (Cascade Set Point Thermostat- Based).

NOTE: This can be accomplished by selecting the demand configuration parameter in the Service/Setup Menu. See Section 1 of this manual for complete details of the SmartTouch controls.

2.Set the system setpoint to the max user setpoint. Max user setpoint will allow the boiler to operate without reaching this setpoint. The boiler will require a load large enough to dissipate a large portion of the heat it is generating.

3.Simulate a call for heat by placing a jumper wire across the enable contacts on the low voltage terminal strip located at the rear of the unit (FIG. 2-3).

4.Allow the unit to progress through its normal diagnostics and pre-purge programming.

5.Allow the unit to fire and operate until the temperatures stabilize. This occurs when the inlet and outlet

temperatures are rising together and the Delta T ( T) is maintained.

6.When the unit stabilizes, begin to slowly shut off the isolation valve on the outlet piping of the boiler (see FIG. 2-4). This will begin to restrict the flow and simulate a low flow condition.

7.While slowly shutting off the isolation valve, refer to the Burner Screen to watch the behavior of the boiler. On this screen, you will witness each individual control module modulating its’ respective burner’s firing rate

	while reacting to the rising		T.
8.	When the	T reaches	50˚F for an individual heat
	exchanger, the control for the heat exchanger will
	attempt to modulate the firing rate down to protect it
	from low flow conditions.
9.	When the	T reaches	60˚F for an individual heat

exchanger, the control module for the heat exchanger will turn off the respective burner.

NOTE: The Temperature Menu will show the inlet and outlet temperatures for each individual heat exchanger.

Service Manual

10.Restrict the isolation valve until both control modules have shut down. If both control modules have been shut down, the test was successful.

11.Disconnect the jumper wire from the low voltage terminal strip connected in step 3.

12.If necessary, reset the demand configuration in the Service/ Setup Menu to the required operational mode.

NOTE: See Section 1 of this manual for complete details of the SmartTouch controls.

13.Completely open the isolation valve on the outlet piping of the boiler.

14.Resume operation.

NOTE: This lockout is a soft lockout. Once the T has decreased to an acceptable level and there is a call for heat, the unit will fire again to meet the demand.

Figure 2-3Low voltage terminal strip & enable contacts

LOW VOLTAGE CONNECTION BOARD

	1	ALARM
	2	CONTACTS
	3	RUN TIME
	4	CONTACTS
	5	LOUVER
	6	PROVING
	7 MODULE 2
	8	FLOW SWITCH
	9 MODULE 1
	10 FLOW SWITCH
	11 TANK
ENABLE	12 THERMOSTAT
	13 R ENABLE
CONTACTS	14 W
			LBL20052 REV B
	15 SHIELD GND			MOD
	16 A
	17 B			BUS
	18 SHIELD GND
	19	(+)	0 - 10V INPUT
	20	(-)
	21 SYSTEM
	22 SENSOR
	23 OUT DOOR
	24 SENSOR
	25 TANK
	26 SENSOR
	27 SHIELD GND			CASCADE
	28 B
	29 A
	30 SHIELD GND

Figure 2-4Adjust outlet isolation valve

ADJUST OUTLET

ISOLATION VALVE

ONLY

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