Ask Experts Questions for FREE Help !
Ask
    bdavey543's Avatar
    bdavey543 Posts: 3, Reputation: 1
    New Member
     
    #1

    Dec 5, 2008, 02:42 PM
    New Thermostat not functioning
    I recently "upgraded" to a digital thermostat so I could program heat cycles while out of the house. The HVAC unit is an Intertherm sealed cumbustible furnace model number MGHA-056ABFC-01 that runs on propane. The entire unit sits in the house and it has two wires going to the thermostat (red and white). The digital thermostat I installed is a Honeywell RTH230B, 5-2 programmable. When I installed the new thermostat I connected the red wire from the fan to the Rh terminal on the thermostat and the white heating wire to the W terminal.


    The problem is that I can turn the heat on and off at the thermostat but it will stay on constantly. It won't cycle to the temperature I set.


    Any suggestions?
    hvac1000's Avatar
    hvac1000 Posts: 14,540, Reputation: 435
    Heating & Air Conditioning Expert
     
    #2

    Dec 5, 2008, 04:07 PM
    Does this unit have A/C.
    Does this unit have a Heat off Cool selector switch on the unit itself.
    bdavey543's Avatar
    bdavey543 Posts: 3, Reputation: 1
    New Member
     
    #3

    Dec 5, 2008, 04:55 PM
    No A/C. No switch on the unit.
    The Unit has fan settings of off, on, and fan.
    Its heat only.
    hvac1000's Avatar
    hvac1000 Posts: 14,540, Reputation: 435
    Heating & Air Conditioning Expert
     
    #4

    Dec 5, 2008, 05:02 PM
    With only two wires you will have no fan control from the thermostat.

    The terminals to use are the R and W on the furnace and the RH and W on the thermostat.

    This part I have no idea what you mean

    When I installed the new thermostat I connected the red wire from the fan to the Rh terminal on the thermostat and the white heating wire to the W terminal.

    The red wire has no business on the fan to start with so this is confusing.

    You might try and isloate the problem by removing the wires from the thermostat and then attaching and unattcahing the wires together to see if the furnace turns off and on normally. If so then you have a thermostat problem.
    bdavey543's Avatar
    bdavey543 Posts: 3, Reputation: 1
    New Member
     
    #5

    Dec 5, 2008, 05:06 PM
    The thermostat I replaced was a non-digital one but it worked fine. Why would it control the fan and heat just fine but the new one won't?

    As for the wires: there were two wires (red and white). THe white one connects to the heater and the redone connects into the limit switches and the wiring and ultimately the fan.

    Thanks for your help.
    hvac1000's Avatar
    hvac1000 Posts: 14,540, Reputation: 435
    Heating & Air Conditioning Expert
     
    #6

    Dec 5, 2008, 06:07 PM
    Did youtry my suggestion to check the thermostat?

    You might try and isloate the problem by removing the wires from the thermostat and then attaching and unattcahing the wires together to see if the furnace turns off and on normally. If so then you have a thermostat problem.
    letmetellu's Avatar
    letmetellu Posts: 3,151, Reputation: 317
    Ultra Member
     
    #7

    Dec 5, 2008, 06:59 PM

    The only two wires you need to worry about are the two that are coming out of the wall, Connect one (the red) to the R terminal and the other one (the white) to the W terminal.
    Don'tworry about where they go from there unless you have changed some of the wiring.
    mygirlsdad77's Avatar
    mygirlsdad77 Posts: 5,713, Reputation: 339
    Plumbing Expert
     
    #8

    Dec 5, 2008, 07:17 PM

    I would start by trying hvac's advice. If this seems to make the furnace run(when wires are together) and shut down(when wires are apart), then you need to make sure you have your programmable thermostat set up correctly. You may be turning the heat up when the thermostat is preset not to run at that time of day. There should be a HOLD button on the thermostat. Press Hold, a light should come on that says hold on the digital readout. Now set the thermostat to desires temp and see if it doesn't work. Best of luck, and let us know what you find.

Not your question? Ask your question View similar questions

 

Question Tools Search this Question
Search this Question:

Advanced Search

Add your answer here.


Check out some similar questions!

A/C Condenser fan not functioning. [ 15 Answers ]

My a/c is not working. The fan is blowing air but it is not cold air. It seems that the condenser fan is not kicking on when it is supposed to. We thought that it was the motor, because it would turn some, but slowly as if the bushings inside the motor were bad. Well, I got a new fan motor,...

Condenser and fan not functioning [ 5 Answers ]

I have a four year old amana central air unit (prestige ultra, 60,000 BTUs). Last night I noticed it wasn't working. The furnace blower turns on, but nothing happens at the condenser unit. I checked the fuses at the condenser power box and the house fuse box, all are fine. The 240 Vac is...

Slow functioning [ 3 Answers ]

Hi there, I am a newbee here, I guess this forum is something I have been looking for to get improved, so my question: my PC is operating too slowly, how can I make it work fast, thanks in advance.

Wet socket and one other not functioning [ 3 Answers ]

About 6 months ago my patio wet socket and another normal 110 socket in my garage stopped functioning. I checked all my breakers and none were tripped. Nothing else in the house is not working, just those two sockets. Any thoughts on what it might be? I replaced one with a new socket, but there is...

Av not functioning [ 2 Answers ]

Hi I just tuned in my television it is a bush ak20 with a scart socket, using a universal remote. It changes the channels and volume but it won't change to av channel with the button that's on the remote and I can't play my playstation 2 with no av I'm going mad here people help!!


View more questions Search