I just bought a new house, the cover of themostat is lost, so I decide the replace the new one

The old themostat has 8 wires:
- a red wire connect to R
- a green wire connect to G
- a yellow wire connect to Y
- a blue wire connect toB
- a white wire connect to W
- 2 black wires connect to X2

The new themostat has 6 slots
- O
- B
- Y
- W
- RH
- RC
- G
- C
The RH and RC are connected with a black wire.


Can some one show me how to connect 8 wires to the new themostat.
Thank you very much

Sorry, the new themostat has 8 slots (not 6)

I just bought a new house, the cover of themostat is lost, so I decide the replace the new one

The old themostat has 8 wires:
- a red wire connect to R -- 24V+
- a green wire connect to G -- FAN
- a yellow wire connect to Y -- COOL
- a blue wire connect toB -- basically neutral (ground... sorta) Could be change over-energize to heat- but since you listed no C here... i'd assume it is your neutral... and probably a york or trane stat... blah blah blah blah blah.
- a white wire connect to W -- HEAT
- 2 black wires connect to X2 -- EMERGENCY HEAT?

The new themostat has 6 slots
- O -- change over (this would be 'typical' for a newer heat pump) energize to cool
- B -- change over (this would be 'typical' for an older heat pump of a few brands) energize to heat
- Y -- Cooling
- W -- Heat
- RH -- 24v+ heat
- RC -- 24v+ cool
- G -- Fan
- C -- neutral
The RH and RC are connected with a black wire: because typically heating and cooling is off of the same transformer power... but if you have two separate power sources for heat/cool, you would remove the jumper and wire accordingly.


Can some one show me how to connect 8 wires to the new themostat.
Thank you very much

You didn't say if you have a furnace, straight a/c, heat pump, hydronic, etc etc type of air conditioning... so can't give much more info.

we need to run new themostate wire n hook up how?

B - could be reversing valve (energize to heat). It can also be common.

X2 can be an indicator or the emergency heat relay.

Rh will be connected ro Rc and be called R.

B is probably the reversing valve (energize to heat). O is more common - energize to cool.