I just bought a Noma Programmable Thermostat from Canadian Tire. My original thermostat was called a York and it is old with mercury capsules inside.

The original wiring is as follows:
Green to G
Yellow to Y
Orange to O
Brown to B
White to W
Red to R
Beige to X

Note that the new thermostat can handle a humidifier but our furnace does not have a humidifier so this functionality will not be used.

The new Noma Programmable Thermostat has only the following wire designations:
W
RH
RC
Y
H1
H2
C (has no screw)
G

I assume that:
white will go to W
yellow will go to Y
green will go to G
but how do the other wires go?

The furnace is used for heating, a/c, and uses a heat pump when the temp goes below 15. There is no humidifier.

Many thanks for your help.

Take Noma junk back and get a Honeywell.

I've never seen H1 H2 before on a stat.
https://www.askmehelpdesk.com/heating-air-conditioning/heating-cooling-maintenance-repair-troubleshooting-frequently-asked-questions-58313.html#post268211

I also don't like Noma, Hunter or Lux thermostats. I'm always replacing them, and on heat pumps we are always going to homeowners homes to rewire them correctly