[mburtonsr]

I have a White Rodgers 2 stage heat/1 cool model 1F58-72 heat pump thermostat that the kids knocked off the wall, and now it's 29 degrees. The tabs were all 30 years old and they slid right off as it hung from the wall. I need the wiring diagram to get some heat going. The back plate gives the # 2744C, with red on R, green on G, yellow on Y1, white on W2, blue on L, black on E, orange on O, but there is also a X1 & B. Some sites say the black goes on B instead of E. Maybe you can help me solve this. This is a Carrier model #3808030300 unit. Thanks in Advance!

[Grady White]

B is usually for blue (reversing valve energized for heat as in Rheem, Rudd, & Weather King eqipment). Carrier uses O (orange) instead of the B terminal.

What wires do you have which look like they may have been connected?

[mburtonsr]

The red on r, white on w2, and I think black was on e, but it could have been on the b because it was partially screwed out.

[Grady White]

I'd leave the black on E. I doubt the "B" was used. Normally either O or B is used not both. With a Carrier unit you would use O.

[mburtonsr]

Ok, understood. We really appreciate the answers/help.

[mburtonsr]

Here is the new wiring attempt, thanks again!

[Grady White]

Is it working now?

[mburtonsr]

No it didn't fire up. I put in a new power relay, checked 240v fuses, board on Carrier doesn't looked burnt, didn't see any type of line fuses or fuse on the board, so I've done all I could think of, funny thing is I can press the power relay contact breaker for a second and get the unit to come on but I have no power at the thermostat. The unit in the attic has 240 coming in at the transformer, but not 24v coming out so that's my next change out if I can find one, waiting for the service center to open, just hate to spend, but looks like I have to.

Thanks

[Grady White]

With 240 in & nothing out, it sounds like the transformer is toast. If you want to protect the new one, you can install a fuse (5 amp automotive) in the 24 volt out line.