Honeywell Mabs Ez 2 Manual

							MASTERTROL® AUTOMATIC BALANCING SYSTEM™ (MABS®) EZ ZONE (EZ-2 AND EZ-4) CONTROL PANELS
11 69-1360–2
Thermostats
The panel can use almost any four-wire (R,W,Y,G) thermostat. 
Each zone requires its own switching subbase with either 
manual or automatic changeover. See Table 1 for 
recommended thermostats.
HEAT PUMP OR MULTI-STAGE THERMOSTATS
Heat pump or multi-stage thermostats are not required for the 
MABS EZ panels because a timer in the panel brings on the 
second stage. A heat pump thermostat is used only when 
emergency heat control from the thermostat is desired. Use 
only Table 1 recommended heat pump thermostats.
EMERGENCY HEAT MODE
An emergency heat switch is located on the side of the panel 
and can be accessed without removing the cover. A heat 
pump thermostat is used only when emergency heat control is 
desired from the thermostat instead of from the panel.
Energizing the L terminal on the zone thermostat or switching 
the Emergency Heat switch to the On position places the 
system in Emergency Heat mode. This switch does not initiate 
a call for emergency heat and prevents the first stage (heat 
pump) from being used on a call for heat.
Fan On In Heat
The system fan can be set to come on with a heat call, as 
required, with a hydro-air, heat pump, or electric heat system. 
Set DIP switch 8 to the On position to activate this mode. 
Otherwise, leave it in the default Off position.Second Stage Emergency Heat Jumper
A jumper is installed on the jumper block to energize W2 
output during a call for emergency heat. If there are two forms 
of auxiliary heat, one can be connected to W2 as the second 
stage of heat and the other to E as the emergency heat stage. 
See Fig. 4.
Table 8. DIP Switch Settings.
DIP Switch 
NO.Switch Function 
with DIP Switch 
Off (Default)Switch Function 
with DIP Switch 
On
1 3.5 minute Purge 
with fan on2 minute Purge 
with fan off
2 ZMS 160°F (71°C) 
heating limitZMS 120°F (49°C) 
heating limit
3 ZMS 40°F (4°C) 
cooling limitZMS 48°F (9°C) 
cooling limit
4 Normal operation Test mode; 
accelerated 
timings
5 See Table 4. _.
6 See Table 4. _
7 See Table 4. _
8HVAC unit- 
controlled fanFan on with call for 
Heat 
						

							69-1360–2    G.H.    Rev.  9-01 www.honeywell.com/yourhome 
	

 
	



 
	



	



 



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MASTERTROL® AUTOMATIC BALANCING SYSTEM™ (MABS®) EZ ZONE (EZ-2 AND EZ-4) CONTROL PANELS
TROUBLESHOOTING
The primary diagnostic tools are the system and damper status LEDs. See Table 9 for troubleshooting guide.
Table 9. Troubleshooting Guide.
Symptom Problem Solution
No LEDs light No power to the panel.•Check for 24 Vac across TR2.
•Check circuit breaker; if hot, a short exists in 
thermostat or damper wiring.
Erratic operation Insufficient voltage.
Incorrect configuration
Panel in Emergency Heat mode
Panel needs resetting.Check for 24 Vac ±10% across TR1 and TR2.
Verify jumpers and DIP switch setting for correct 
configuration.
Check position of Em Heat switch.
Press Boot button and recheck system operation.
Heat or Cool LEd flashes 
continuouslyHeat LED flashing.
Cool LED flashing.ZoneMAX Sensor tripped on high limit.
ZoneMAX Sensor tripped on high limit.
Heat pump works in 
Heat but not in Cool or in 
Cool but not in HeatIncorrect thermostat.
Incorrectly wired.Install the correct thermostat.
If equipment is heat pump, be sure there is a Y1 or 
W1 jumper installed.
Emergency heat not 
coming onIncorrectly wired.
Incorrect thermostat.Verify thermostat and equipment wiring.
Verify correct thermostat is used.