Honeywell L7224A,C, L7248A,C,L installation instructions Condition, If no 120 Vac, replace control

L7224A,C; L7248A,C,L OIL ELECTRONIC AQUASTAT® CONTROLLERS

Table 11. Troubleshooting Guide

System	Diagnostic
Condition	Condition	Check	Action
Boiler is hot,	Display is ON.	120 Vac at C1-C2	• 120 Vac at C1-C2, check wiring to pump.
house is cold.			• Wiring OK, is pump running?
			• If not, replace the pump.
			• If pump is running, check for trapped air or
			closed zone valves.
		Boiler below the Low Limit	—
		temperature, wait for boiler to go
		above Low Limit temperature.
		Boiler above LL? If yes, check for	• If no 120 Vac, replace control.
		120 Vac between ZC and L2.	• If yes, check zone relays, circulators and
			wiring.
		ELL setting (L7248L only)	• Set ELL to Off for multizone system (see Fig.
			11).
			• Set ELL to On for External Low Limit (see
			Fig. 13).
		Boiler above LL? If yes, check 120	• If no 120 Vac, check C1-C2 (see above).
		Vac at ZR-L2 (only L7248L with	• If yes, check the External Low Limit control.
		ELL set On)
Boiler is hot,	Display is ON.	Boiler Demand signal from the	• 24 Vac on T-T (or 0 Vac on ZR-L2), check
no hot potable		water heater (either 120 Vac at	wiring to water heater
water.		ZR-L2, or 0 Vac on T-T; depends	• Wiring OK, check the water heater
		on installation and “duu” setting)
		“duu” setting	• Set duu to ON if 120 Vac water heater
			demand is connected to ZR
			• Set duu to OFF if open/closed water heater
			demand is connected to T-T
		Check DHW Module and DHW	• DHW Module not properly connected and/or
		Sensor	DHW Sensor improperly positioned

ZONE 2	TO ADDITIONAL R845A
	RELAYS FOR OTHER ZONES
CIRCULATOR
	1	L1	L7224
	L2 (HOT)
R845A RELAY ZONE 2
6
5
3		SENSOR
4
1			ZR
			L1
		LINE
2
		VOLTAGE	L2
		CIRCULATOR	C2
	ZONE 2
	LOW VOLTAGE		B2
	THERMOSTAT
1 POWER SUPPLY. PROVIDE DISCONNECT		LINE	C1
MEANS AND OVERLOAD		VOLTAGE	B1
PROTECTION AS REQUIRED.		OIL BURNER
		RELAY	ZC
2 CONTROL CASE MUST BE CONNECTED
TO EARTH GROUND. USE GROUNDING
SCREW PROVIDED.

	LOW
	VOLTAGE
2	THERMOSTAT

T

T 3

2

1

LINE

M27115

Fig. 9. L7224A,C multizone system with circulator connections.

11 68-0281EFS—05