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Replaced Thermostat and now Blower Motor will not run

Greetings, I replaced an original rheem 41-20804-15 thermostat for our rheem heat pump. With a Honeywell RTHL3550D, the cooling worked fine. When I tried the heater, the blower ran for 2 minutes then shut off. I put the original thermostat back and now the blower still does not come on. The whole unit (blower and heat pump) are outside. I checked the fuses and that the unit is getting power. The squirrel cage for the blower turns freely and if i push in on the relay the heat pump fan kicks on. Any suggestions? thx, Rocky

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Sounds like a set up issue on the tstat. You say this is a packaged unit, inside the machine you should find where the tstat wires hook up. Typically red is power yellow is compressor orange is reversing valve white is emergency heat green is blower. Put red and green together, test blower. Then red green and yellow, make sure blower works again. If blower runs both ways it's either the tstat wire or tstat itself. Make sure you are landing wires on dedicated heat pump terminals, make sure in settings you are set up for heat pump with back up electric heat and TSTAT CONTROLS THE FAN. Good Luck. Also if there is a switch on the tstat for gas or electric on the back you want electric.

Posted on May 12, 2017


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Posted on Jan 02, 2017

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SOURCE: Rheem RHQA Heater:Blower works but no heat.

Is there a setting on the thermostat for Auto or Fan? If so, make sure it is in the Auto setting. You will have a contactor that turns on the elements and a relay for the fan. Follow the wiring diagram to see which relay energizes the fan then unplug it to see if the fan stops.

Posted on Nov 03, 2009

  • 1515 Answers

SOURCE: Honeywell thermostat TH6110D1021. Blower comes on

Hi, You are right, fan is on a time delay in the heating cycle, and after burners fire that is when this delay comes into play. You have a preset factory temperature that determines the cycle on time for the fan, and the off time after the burners shut down also. This will not be in the thermostat, but in the fan/limit control the is mounted on the face of the furnace, with a probe inserted into the fire box.Depending on how old or new this unit is, will depend on the type control you have.It may be just a high limit switch, or the 1st I mentioned.If so, It rotates in the burner as the temperature rises, to turn the fan on and off.Disconnect power, remove cover, and 2 screws.Slowly remove the control and gently clean the probe. Turn the dial if this one has it and you will be able to hear it click. This click is contacts closing to start fan operation.Reinsert and try again. If problem continues, you will have to replace it.They do tend to stick closed/on, in the heat cycle from time to time and a cleaning sometimes will solve this problem. Not knowing how old this furnace is and type, make it difficult to give you a correct diagnosis, so check this fan control as I have explained, and if your system is of a different type, please let me no so I can correct this problem. Sincerely,

Posted on Dec 11, 2009

  • 3162 Answers

SOURCE: Furnace blower fan problem

Hi check out the fan control switch could be dirty itsounds like this is nit cutting to let fan run also check setting fan off fan on , temp rise and fall

Posted on Feb 06, 2010

  • 588 Answers

SOURCE: Outside heating unit runs all the time

Usually when the furnace blower motor runs all the time
The limit switch or rollout switch is usually open or bad.
The furnace board is seeing that one of those switches is open, so it brings the blower on to try to get the heat out of the combustion chamber area, so the switch will close. But if the switch is bad and won’t close, the furnace board will keep the blower running continuously.

Posted on Feb 22, 2010

  • 588 Answers

SOURCE: Heat PumP: Rheem Two Stage Heat, One Stage Cool Thermostat Replac

R = R with jumper to RC hot side of transformer
B = Reversing valve
Y = Compressor relay
G =Blower
C = common on transformer (X on old t'stat)
W2 = Auxillary heat
E = Emergency heat

Posted on Mar 16, 2010

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