Tamar one thing I should have been clear on is that the 30 kwh difference is running both units + the fireplace roughly 50% of the time for additional heat compared to running only 1 unit with no fireplace. I'm expecting to an even greater difference in usage when running the fireplace as well. We were not charged when the contractor decided to upgrade the tonnage from 6-8. The bid price remained the same. In all reality, we actually made money on the increase. Our utility offered a $750 per ton rebate so the increase saved us $1,500. Our contractor was aware of the utility rebates and let us know that regardless, all rebates and tax incentives were ours independent of the bid. One thing I would like to make clear is that up to now our contractor has been fantastic and responsive. We called last Monday about our concerns on energy usage and he was out the next day running tests. He checked flow rates, delta, made adjustments to the pump flow rates, return and supply temps, etc. He also took readings using a temperature probe because the units COP reading was low. He took the time to make calls and eventually got a call back from Modines engineer who took his readings and calculated the COP as 4.9. The other unit had a temp sensor out for the GWO. He will be back as soon as the sensor comes in to take a look at the airflow on unit I have concerns with. He determined at the unit everything was functioning properly and at the time I did not know we had an airflow issue. The duct work, install, was timely and professional. All solid duct, insulated, connected doped and taped. My reason for mentioning all of this is that I have no reason to think that our issues will not be taken care of, however I'm hoping to inform myself enough to ask the right questions when he does come back, especially about the oversize concern. I'm not concerned about what we paid or getting anything back, just want to get our setup running as economically as possible with the least cost or time to us or the contractor.