Build a fair comparison
Collect electric and gas bills from before and after installation. Include usage, billing dates, days in each period, rates, and fixed charges. Keep the installation date and any partial billing period.
Compare similar weather and indoor settings. Note changes in occupancy, electric vehicles, hot-water equipment, and other large loads. A colder or longer month is not a direct comparison with a milder one.
If the heat pump replaced gas heating, include the gas change. If gas appliances remain, keep their usage and account charges in the total.
For Xcel customers, the utility publishes service-area rate books. The applicable account tariff and bill details matter more than a general online rate. Xcel rate books.
Check what supplied the heat
Save thermostat settings and available operating history. Ask the HVAC provider to verify whether the compressor, electric backup, or a retained furnace supplied heat and whether that matches the intended sequence.
Ask for the installed models, the commissioning record (installation setup and operating checks), and the assumptions in any sales estimate. Professional commissioning guidance. Nearly continuous runtime alone is not an energy measurement. A bill alone also cannot identify a control fault.
Do not disable backup heat or change installer settings to chase a lower bill. Have the provider assess settings and actual operation.
Separate three questions
First, is the equipment working as designed? Second, does the design meet the home's needs? Third, does its operating cost meet the expectation you were given?
A system can need a repair or setup correction. It can also operate properly while costing more than expected under local rates. Those situations call for different next steps.
Ask for an itemized explanation of any mismatch, with measurements or stated assumptions. A response that only says “heat pumps are efficient” does not resolve a tripled bill.
Your next step is to send the provider both energy histories, settings, and installation documents. Request a documented operating check and a weather-aware comparison of total energy cost. That gives you a basis for correcting a problem or revising an unrealistic estimate.