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Rick Mather
Rick Mather, HVAC Technician
Category: HVAC
Satisfied Customers: 3634
Experience:  35 years experience, HVAC
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I have a trol-a-temp Mastertrol Mk II Auto Balancing Zone Control

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I have a trol-a-temp Mastertrol Mk II Auto Balancing Zone Control System set up for 2 zone forced air heating/cooling with each zone controlled by a LUX 700/900 Electronic Thermostat. The Hallmark furnace fan is controlled by a Honeywell L4064B (or T) Fan and Limit controller. The fan will turn on and run for 1-2 minutes every hour when not called for heat. I've switched thermostats with no resolution. If the Fan and Limit Controller is the source is this a weekend warrior job or a professional?
Fan and Limit is not that bad to replace and a novice can handle this
Customer: replied 6 years ago.

Are you saying that the problem is with the Fan and Limit switch and if so how can this be verified? Are there any test(s) that should be run to eliminate other possibilities?



Well the only link to the zone panel for fan operation is the G terminal
Customer: replied 6 years ago.

Rick - I need more help than this; I don't understand the response. I know there is a PIRR fan relay; is this the G terminal? If you suspect the fan relay how can it be tested? What I am looking for is a way to verify the bad component so I can isolate and then replace.


Well if you disconnected the G terminal and it still has a problem then that would leave the damper panel has not part of problem and look at fan control board on furnace
Customer: replied 6 years ago.
Rick - We're not communicating too well. I'm not trying to be difficult but my questions and your answers lead to more questions which are unanswered. I suggest we cancel this troubleshooting attempt. How do I get someone else to provide assistance?
Good luck
Customer: replied 6 years ago.
Relist: Answer quality.
I was very dissatisfied with this, my first experience. After 4 tries my problem was not solved and each response did not answer my question. There was no troubleshooting provided; only 1 sentence responses that required follow-up questions.
Well need as much info on this end to give you the right answer sorry you feel that way
Customer: replied 6 years ago.
Please let me now what additional informaton you need. When I receive the replies it starts off from the first question I asked which identifies the problem I have and the equipment I have. In short, my forced air furnace fan turns on without a call for heat and runs ~1 minute a few times per hour. If you need me to identify the equipment models and such I'll be happy to provide this again.
Thermostat make and model number would be big help and which panel do you have also for the zone dampers

Edited by Rick Mather on 1/17/2010 at 7:04 PM EST

Is any one of these your thermostat

That fan and limit has to heat up a heli coil enough so it will make contacts so I don't think its the fan and limit
Customer: replied 6 years ago.
I have been away for a few days. Thanks for the reply. My thermostats are the Lux TX9000 model which is dicontinued. The TX 9000A Manual at the Lux website link you provided (thanks) is similar in wiring hook-up to mine. You asked "which panel do you have for the zone dampers?". I have a Trol-A-Temp Mastertrol Mark II Automatic Air balancing System panel (I think this is what you are asking about). It is set up for 2 zone heating/cooling.
If the furnace has been on prior to when the the fan blower comes on it may be just blowing excess heat out of furnace also
Customer: replied 6 years ago.

OK; i turned the thermostats down so the furnace would not get called for heat and the fan did not run. In other cases when the thermostat was not turned down the fan would run even though the thermostats did not call for heat. So, it appears there is some "excess" heat that the fan is trying to dissipate, or, the fan controller/relay, etc is bad. Any other way to test this?


You asked questions about the thermosats the other day. Are there any troubleshooting steps required for these?

Customer: replied 6 years ago.
Thanks. XXXXX test this? If so, how. If this requires replacement what needs to be replaced? The entire Fan and Limit switch or just the heli coil?

Just replace it but you have to know the length before you order it I believe there on second page of this link

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