Our Furnace doesn't come one when we turn the thermostat on, how come?

Question

we replaced the thermostat and still nothing happens. we turn on the thermostat, there's no click. there is electricity going to the unit all around and the pilot is lit. there is only a red and white wire from the furnace to the thermostat, would it be the t-stat wiring? the motherboard? maybe a fuse needs to be replaced? bad blower motor? i don't know

Answer 1

If there is a problem with the thermostat you can test by just taking the two wires going to the thermostat and wiring them together.
If the heater doesn't fire then the problem is in the furnace.
If it is an older style Day and Night furnace, look along the top of the furnace for a reset button, that is the blower limit switch.
It stops the 24 volt signal to the gas valve.
Reset the switch, check your filters, and replace if needed.
If a different brand, use a meter and check your limit switches for continuity. Replace or reset the one that is bad (no continuity).
Because of limited info. provided, diagnosis is not easy.

Answer 2

This Site Might Help You.

RE:
Our Furnace doesn't come one when we turn the thermostat on, how come?
we replaced the thermostat and still nothing happens. we turn on the thermostat, there's no click. there is electricity going to the unit all around and the pilot is lit. there is only a red and white wire from the furnace to the thermostat, would it be the t-stat wiring? the motherboard?...

Answer 3

Maybe the problem is not the thermostat. Are you out of fuel. Is the filter clogged. Is the pilot lit. Maybe a circuit breaker needs to be reset. I'm no furnace expert but I would check these things before I called a repairman.

Answer 4

That depends on what is actually happening when you turn up the thermostat. It could be the thermocouple or the control board. For a step by step troubleshooting guide, check out the furnace page at my source.

Answer 5

a similar thing happened to me. if the thermostat itself is clicking, but the furnace is not turning on it may be a fuse.
most furnaces have an on/off switch (like a light switch) that has a fuse inside the switch. it may need to be changed.

Answer 6

If the thermostat replacement has mercury in it, it needs to PERFECTLY level or it won't work properly. The other thing to check is the voltage setting on the anticipator. This needs to be set to the same voltage as your relay to the burner. Look for a sticker on the box that has the RESET switch for your burner. You'll find somthing like " .2 " or ".4". Set the anticipator inside the thrmostat to that number.