New air handler fan control with system 2000 boiler

68Camaro396

New hydro airhandler uses a microprocessor that delays the fan on/off for 45 seconds. The on time is fine but the off time is low my current handler runs 4 to 10 minutes when the system 2000 is in heat recovery mode. Is there a way to keep the fan on longer?

Need to replace an old A/C and air handlers Model 24MBX-3HW. Two air handlers one in attic and one basement and Energy Kinetics system 2000 boiler for heat, is there a better set up with the control boards in new units? I currently have a dual 24 volt transformer set up. In cooling mode the thermostat turns on the fan motor via the relay. In heating mode the thermostat turns on the boiler only. The fan motor is also wired to 120V thru an L6006C aquastat mounted to the water pipe. The current set up works fine but will like to get better control from a new unit if possible. I do get some short cycling on the unit in the attic. I can also feel a slight temp overshoot downstairs. Not sure if you can wire the new air handler motors to the aquastat and bypass the control board. Want to stick with First Company to get the same size unit. I would also like to install the optional freeze protection kit on the unit in the attic

Robert O'Brien

Wire zone valve end switch to R-G on air handler. Fan will run as long as ZV is open

neilc

picture,
of the camaro, bumper to bumper, with the hood up so we can see the piping,
# wait a minute

68Camaro396

neilc

ty

68Camaro396

Thanks for the great tip on wiring the fan to the zone valve. The good news is I have extra wires from the attic to the basement, but my zone valve Erie AG13A030 doesn’t have end switches. If I get the same brand ZV with end switches can I swap out the motor control or do I have to replace the entire valve?

Roger

@68Camaro396 , you're right on track with the answers above. The zone valve you have is a "pop top" (Schneider Electric purchased Erie), so the head can be changed out to an end switch version for your air handler. It should have been installed that way originally so the air handler will only run with hot water circulating through it during the heating mode and when purging. The blower off delay works, but it may not be the purging zone and could blow cold air on occasion; the end switch is a better solution. The other good news is that the purge drives considerable energy savings and the blower off delay and the end switch both serve that function.
Best,
Roger

PS: Lots of heating power in our low mass boilers in buildings, but I'm sure that Big Block '68 Camaro of yours commands the road!