How do you wire a new thermostat. accidently chopped wires from my old Danfoss one while decorating. I now have a white wire, with 4 inside it hanging. Bought a Herstmann but wiring is confusing?

SOURCE: Old thermostat wiring doesnt match up with new thermostat

Look at the instuction booklet (or on the T-stat board) for a switch for the reversing valve.

Some systems reversing valves are in cooling mode when energised, some are in cooling mode when NOT energised.
You are looking for the switch (Usually very tiny, or a different jumper setting) that will change the position of the reversing valve when calling for heat/AC.

This is not a switch like the typical "ON OFF AUTO, HEAT COOL EMG HT switches. It will be on the board itself or the back of the T-stat.

SOURCE: Help - I am trying to install a honeywell RLV4300A

You will have to have schematics from the old wiring diagram. Then you will have to confirm its consistency with actual old wiring before you can be sure that the wires run to the proper places on the old heater and a/c system. This sounds like a gas furnace and is simpler than a heatpump. Once you know what distinguishes the wires with the same color, you should label them and then you may call them a different color if they were wired with wrong wire colors. You may be in luck if you go to the furnace control box an look at the terminals.. They are usually labeled with a R for Red and W for white and Bl for Blue and B or Black. If you have other colors on these then it sounds that it was wired with wire spare wire by someone who knew what they were doing but neglected to leave a path for someone else follow.
You may be able to use a continuity tester of circuit tester to id these wires that are in question...
ie, once indintified, you can match with the requirements of the new stat.

SOURCE: Honeywell RTH 230B Thermostat Wiring

put the jumper back in RC and RH and that should do it.

SOURCE: Wiring new RTH2310 DIY Honeywell

is the j2 jumper on the backside of the display set for hg instead of he - g is gas/oil e is electric - if correct take thermostat wires off screws and turn power back on - see if burner fires up with no thermostat wires connected - old wires could be touching somewhere when put on new thermostat

SOURCE: I just bought a Honeywell

I just installed a Honeywell 5.2 Day RTH2310B Programmable thermostat and I had to deal with the same situation: 2 wires, one white one black. After reading the edvice in one of the blog, the solution that worked for me was: BLACK ON Rc terminal and WHITE on W terminal. My furnace is running fine now. Hope it helps.