I’m not there so I don’t know what might be wrong - but this does not seem right to me. You should have much longer run times.

I hope at the time of installation that you purchased the 10-year parts & labor extended warranty and are maintaining an annual service contract with the installing company. That would provide your greatest peace of mind and greatest leverage with Carrier should further problems arise.

Was a Manual J & Manual D calculation performed?

IMPO

SR

Depends on both inside and outside conditions....I am not an Infinity or zoning expert. I thought CPH could be adjusted. Mike Home has an Infinity system so I hope he sees your thread and can better answer this question. It would be helpful to know the size of your home, the size of the Carrier system, the size of each zone, and your location.

TD

Zone systems will cycle more especially if only one zone is calling.

The whole system capacity is essentially being used to cool that one room.

In terms of wear and tear: if the zone system is installed properly it reduces wear and tear by reducing over heating problems.

I service the Katy, Texas area.

Do you have the Carrier Infinity touch screen thermostat? For some reason Carrier removed the cycles per hour setting from the touch screen version. The setting did exist in the first generation Infinity thermostat. Decreasing the cycles per hour masks the problem rather than solves it in my opinion.

If you don't have a Infinity thermostat then that could be part of the problem. The Infinity controller has the ability to communicate and manage air flow better than a third party thermostat.

Did you get Infinity zone dampers as part of the installation? They have the ability to partially open and close. They are much more expensive than the standard damper and for this reason installers don't like to use them.

If you do have the Infinity controller, every day at 1 pm the controller does a duct assessment to verify all zones are operating correctly. A static measurement is taken for each zone. If you see this occurring it is normal.

What is the size of the AC and about how large are the three zones? On the low stage the 2-stage condenser is running at about 70% of the total size. It will be over sized for each of the zones. You can also try closing the supply closest to the thermostat as a way of increasing the run time. If you have a zone for the bedrooms, then consider using a temperature set back during the day. It will save energy costs and reduce the amount of cycling for that zone.

Ty Mike for the reply. When our old AC unit died, the inside & outside units were replaced. The TStats, Ductwork & Dampers were NOT changed. A year later the existing Tstats stopped working. They were replaced with an EWC zone panel Honeywell T6 thermostats system.

HVAC Unit- Carrier 16 Seer-they did some sort of calculation to get the right size unit. Our house is 1700 sq ft. split level- 3 conditioned levels…lowest level, office, family room & bath, main level living rm/kitchen, upper level bedrooms. Each zone is probably equal in size with the bedroom area being slightly larger.

It has been explained on a single zone, single thermostat, no zone dampers, meaning the whole house got balanced airflow all the time we would get 3 even cycles per hour. Because of our zoned system, it has to be set up to be able to run all 3 zones if & when needed, so at times we can be oversized for a particular zone at the current conditions, and it will satisfy sooner. So I understand this. My only concern is it ok for it to run for 5-7 mins in one particular zone then shut off?

RE: On the low stage the 2-stage condenser is running at about 70% of the total size. It will be over sized for each of the zones. You can also try closing the supply closest to the thermostat as a way of increasing the run time.

I don’t know what this means…do you mean close the floor vent? Will it hurt the unit or efficiency if we do this?

If you have a zone for the bedrooms, then consider using a temperature set back during the day. It will save energy costs and reduce the amount of cycling for that zone.

Yes, in the winter, we do set back Tstat just by 2 degrees for areas not in use, at work, sleeping etc. In summer, we just keep everything at constant temp because I feel it controls whole house humidity better for those humid days.

Do you know the model number of the AC condenser? That is the equipment which sits outside. The model number should be on a label towards the back of the unit. If you a 2-stage condenser, then it has the ability to run in the low or high stage. If one zone is calling for cooling then the condenser should be in the low stage and stage there until the thermostat is satisfied. Post the model number of the furnace or air handler. That will also be helpful in determining what you have.

You can close the floor vent closest to the thermostat without causing a problem. Try that for a few days to see if it has any affect on the run time.

Hi again Mike. I have to get those numbers during the day. I closed the vent in main living level closest to Tstat which location is directly under kitchen cab facing out, and it is blowing so hard & fast it didn't seem to stop the air much. So I purchased one of those magnets & the air is so hard it didn't stay attached. But it is a very flimsy magnet. there are 3 other vents on the main floor, those are in the floor and face up. I do know this is 2 stage system, the living room is only area calling...it has been set at same temp without any change to create such a demand....it always blows very hard and fast...doesn't seem to start or change to that lower stage & as I am trying to learn how all of this works...I would think it should start low & only go high when there is a great need. But it has been VERY hot here past few days.

Model # 25HNB636A310 Carier Infinity

The Carrier Infinity 25HNB636A310 is a 3 ton 2-stage heat pump. So now we have to figure out why you are not seeing low and high stage operation. I believe the Honeywell T6 thermostat comes in single and two stage cooling versions. You need to find out which version you have. We also need to verify if you have a 2-stage air handler. The model number will give us a clue. It may be possible you have all the equipment for 2-stage operation, but it was not installed correctly. The zoning panel may also be causing the issue. That would be hard for anyone to troubleshoot remotely.

You could ask the installer to come back to your house and demonstrate to you the heat pump operating in the low and high stages. You should be able to do this even without the Infinity thermostat.

Well thank you so much for all of the info. I think it does run in 2 stages at times because at times I can hear a change from low to high or high to low .

Am I correct to think it should start on a low stage and only kick into high gear when needed?

Over the weekend it was extremely hot -high 90s. We have all Tstat set at 73 and leave it there. The main living area has been running hard/fast. It just kicked on but the bedroom area was also calling at same time, so living room is not blowing the air as hard/fast.

The installer has offered to come out and go over everything with us. I just kind of like to understand this better.

Thanks again!