The heat pump should sit on the pad and it should be level. The pad should be needs to be big enough to accommodate the heat pump. If not then have it changed.

Most heat pumps are not going to perform well when the outside temperature is in the 20s. Do you have auxiliary heat strips? If yes are they turned on? If the auxiliary heat is working then it may be too small. In any case the installer needs to come back and fix the situation.

Do you have second stage heat in the system. In other words, if the temp drops to X point does second stage, typically elec resistance heat take over at the low temps when the HP output is lowest. If so, perhaps the call for second stage is not pulling in. Could be as simple as t-stat wiring. Check out the second stage set-up.

thanks both. Would anybody know what the temperature range of the air coming out of the vent for both heating and the cooling? I called the installer this morning before I posted this thread here and told him that the air was not as warm as that of my old system. He said that the air should be below human body temperature.. Well... any temperature below 98 is below....but what's the range though? My old system made by a terrible maker still could send out warm air when it was working, even without heat strip. I wonder why this new system is not???

This post was edited by chueh on Sat, Jan 25, 14 at 11:18

The higher SEER rating does not mean the air will be warmer. It means that the unit will use less electricity to produce the warm air that it does.

Also, the heat side of a heat pump is rated with a different number, HSPF (i think).

From what I can see, the unit bottom is fully on the pad. The overhang to the left is not part of the base.

It would be nice to know the model numbers on both units. If the units are not matched than the performance will not be 15. The other question I would have is what thermostat is on the system.

The vent outlet temp will vary depending on run time and if the sky is falling outside. Is the unit in a basement, crawlspace or attic and are the duct connections sealed?

Carrier Performance 15 Heat Pump 25HCC530A003 and Air Handler FX4DNF031T00. I think that they are matching, but there must be a typo or different match from another company who quoted me for the air handler, instead of FX4DNF031T00, it is FX4DNF037T00 on the written quote.

I use my old Lux 7-day programmable thermostat.

The temperature of the air from the vent feels pretty much the same when it's been continuously running for a while in the morning, day, or night. It gets slight cooler when the system rests a while and then comes back on.

As what I was told by all the technicians to quote and the actually installers, the duct work was fine. The air handler is is the attic. I understand that different manufacturer standardizes things differently, yet my old one was much warmer. It did not take much time to heat the house up before. Now with the new system, it seems taking longer to heat up and maintain the same temperature. it just makes me wonder......

The possibilities are endless why the unit isn't working as it should so it would be a guessing game when I am not there to troubleshoot it. However there is one certainty,YOUR TECH IS A KNOT HEAD. Air below body tempature means it feels cool to your hand. It's also certain that there is a problem. Were this in Tx and I didn't have hvac experience,I would. A Measure and record indoor,outdoor,room and discharge temps. B Have the installer give me his foolish answers in writing. C Hire a repitual company to fix it and write all observations and actions down in both techinal and layman's terms. D File suit in JP court to recover expenses. If I could not afford that,I would ask the largest friend I have to go to thier office and ask if they plan on fixing it.

Thank you for the replies. By the way, what's the difference between FX4DNF037 and FX4DNF031 fan coils? I understand that FX4DNF is a series with STATIC blower, where as FV4CNF is with VARIABLE speed. FX4DNF037 and FX4DNF031 both being static blowers, what's other difference? Thanks

Thank you for the replies. By the way, what's the difference between FX4DNF037 and FX4DNF031 fan coils? I understand that FX4DNF is a series with STATIC blower, where as FV4CNF is with VARIABLE speed. FX4DNF037 and FX4DNF031 both being static blowers, what's other difference? Thanks

The pad is too small for the condenser and its overhang to it's bottom footing. It should be level and correctly centered.

As to air handlers, the FV series is var speed while the FX series is higheff fixed speed. Both come in different sizes for proper and best match as far as performance/efficiency numbers.

Here are the numbers.

3676266 Active Systems CARRIER AIR CONDITIONING PERFORMANCE 15 PURON HP CARRIER AIR CONDITIONING 25HCC530A**30 FX4DN(B,F)031 1000 28400 12.50 15.20 28200 8.50 17000 1 HRCU-A-CB 226 684 Yes

7017567 Active Systems CARRIER AIR CONDITIONING PERFORMANCE 15 PURON HP CARRIER AIR CONDITIONING 25HCC530A**30 FX4DN(B,F)031L 1000 28400 12.50 15.20 28200 8.50 17000 1 HRCU-A-CB Yes 226 684 Yes

3676267 Active Systems CARRIER AIR CONDITIONING PERFORMANCE 15 PURON HP CARRIER AIR CONDITIONING 25HCC530A**30 FX4DN(B,F)037 1000 28800 12.00 15.00 28400 8.50 17100 1 HRCU-A-CB 234 668

6938216 Active Systems CARRIER AIR CONDITIONING PERFORMANCE SERIES PURON HP CARRIER AIR CONDITIONING 25HCC530A**30 FX4DN(B,F)037L 1000 28800 12.00 15.00 28400 8.50 17100 1 HRCU-A-CB 232 684

Your system appears to qualify for Fed Tax Credit.

IMO

This post was edited by tigerdunes on Mon, Jan 27, 14 at 12:06