The thermostat is a simple mechanical one with the plastic lever all the way
to the left is off and all the way to the right is maximum heat. There are
no other adjustments. The problem is when the lever is all the way to the
left, the fan kicks on when its cold but the gas for heating does not come
on. Heat come on only the lever is move more toward the right. (Its been
cold the last few days so the fan has been on constantly.)

Furnace belongs to my MIL and was installed by a contractor about 5 years
ago. I suspect the control wires were hooked up wrong. Does this sound
reasonable? What are the color codes for the thermostat? Anything else I
should check out for her?

On Sat, 13 Jan 2007 16:13:24 -0800, "# Fred #"
wrote:

The thermostat is a simple mechanical one with the plastic lever all the way
to the left is off and all the way to the right is maximum heat. There are
no other adjustments. The problem is when the lever is all the way to the
left, the fan kicks on when its cold but the gas for heating does not come
on. Heat come on only the lever is move more toward the right. (Its been
cold the last few days so the fan has been on constantly.)

Is this a heat pump with gas backup?

Furnace belongs to my MIL and was installed by a contractor about 5 years
ago. I suspect the control wires were hooked up wrong. Does this sound
reasonable? What are the color codes for the thermostat? Anything else I
should check out for her?


There are no real firm wiring color codes. it also depends on what you
have.

# Fred # wrote:

The thermostat is a simple mechanical one with the plastic lever all the way
to the left is off and all the way to the right is maximum heat. There are
no other adjustments. The problem is when the lever is all the way to the
left, the fan kicks on when its cold but the gas for heating does not come
on. Heat come on only the lever is move more toward the right. (Its been
cold the last few days so the fan has been on constantly.)

Furnace belongs to my MIL and was installed by a contractor about 5 years
ago. I suspect the control wires were hooked up wrong. Does this sound
reasonable? What are the color codes for the thermostat? Anything else I
should check out for her?


So don't put the lever all the way to the left.

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HVACTECH2 wrote in message
...
On Sat, 13 Jan 2007 16:13:24 -0800, "# Fred #"
wrote:

The thermostat is a simple mechanical one with the plastic lever all the
way
to the left is off and all the way to the right is maximum heat. There are
no other adjustments. The problem is when the lever is all the way to the
left, the fan kicks on when its cold but the gas for heating does not come
on. Heat come on only the lever is move more toward the right. (Its been
cold the last few days so the fan has been on constantly.)

Is this a heat pump with gas backup?

No, just a natural gas furnace.


Furnace belongs to my MIL and was installed by a contractor about 5 years
ago. I suspect the control wires were hooked up wrong. Does this sound
reasonable? What are the color codes for the thermostat? Anything else I
should check out for her?


There are no real firm wiring color codes. it also depends on what you
have.