New high efficiency unit acting strangely

[ADD2010]

I just got a new high efficiency HVAC unit installed (4A6H5030E1 / American Standard 15S R410A 2.5T Heat Pump and 4TEE3C02A1 / Variable Speed Convertible Communicating Air Handler 31,000-36,000 BTU). I'm located in Virginia and the current temps around here are high 60s, and I have my heat set at 69 degrees. I noticed that when the thermostat says "heat on", the outdoor unit fan spins for less than 1 minute, stops, and starts again, and repeats a few times, all while it is "heat on". It seems like there is some warm air coming out of the vent (although it is very weak and sometimes I don't feel any air at all), but it seems like the house is heating up ok because the thermostat keeps meeting the set temperature. However, I feel it is very strange that the outside unit keeps spinning and stopping -- is this a normal function of a high efficiency system or is something wrong?

Also, the technician that installed it claims that high efficiency units act differently and that the outdoor unit may be spinning and stopping because it does not need to be in "full gear" since it is not that cold outside. He said that as long as the temperature is heating up to what it is set at, then it is ok. Is there any merit to this or do I need to find a new technician?

[BaldLoonie]

I think you need a new technician.

[beshvac]

Should not stop and start

[gary_g]

I'll combine Post #2 and Post #3 into one sentence:

The condenser should not stop and start, and you need a new technician.

Good luck.

[ADD2010]

Oh this is very disheartening since the system is new and expensive. Thank you guys for your input.

[Shophound]

Outdoor unit may have a low pressure switch that is cycling the unit because the system is low on refrigerant. Job One is, should this be the case, to have the tech find the refrigerant leak and fix it. Don't settle for him adding some gas and walking away, unless it was undercharged from the start. New systems can leak...installer error on brazing joints are not unheard of. New coils from the factory can leak. This is what warranties are for.

[ADD2010]

Thanks to everyone for the responses. So the technician came yesterday (yeah, the same guy that installed since there is a 1 year job warranty) and this time he said something about a coil restriction and how the indoor unit wasn't communicating properly with the outdoor unit, so that the fan wasn't turning on when the outdoor unit was turning on, so the unit was getting too hot and was automatically shutting itself off, hence the condenser starting and stopping every 30 seconds or so. They are coming back again today to try to completely fix it (they only managed a temporary fix yesterday).

Any thoughts? Was this the installer's fault or could it be the unit being bad? He seemed to indicate that American Standard units have been having more issues in the past few years...

[pacnw]

First, I agree with the above posters in that there is a 99% chance of an issue in need of fixing.

Second, I do not know the specifics of this model, so following comment may be incorrect for your application.

There may be a low ambient kit on this unit cycling the fan to control refrigerant temp/pressure. This is usually seen on commercial equipment only.

[amd]

and this time he said something about a coil restriction and how the indoor unit wasn't communicating properly with the outdoor unit, so that the fan wasn't turning on when the outdoor unit was turning on, so the unit was getting too hot and was automatically shutting itself off, hence the condenser starting and stopping every 30 seconds or so.

That's plausible, outdoor unit cycling on high pressure limit in heating mode. (assuming that the switch is self-resetting)

[ADD2010]

hello, thanks to everyone who has provided input. the main technician came this morning and appeared to adjust settings on the circuit board on the indoor unit, said everything is working fine. He also mentioned something that I thought strange and since you guys are all very experienced, I wondered what your thought was on this:

He said that there are two things that can mess up a circuit board (hence the reason I was having issues): (1) power surges can cause the circuit board settings to get messed up so that it is not working properly, therefore causing the miscommunication between the indoor and outdoor unit, or (2) turning on the heat and then immediately turning on the a/c can also confuse the circuit board.

Is this a common problem? If so, doesn't that mean that people's hvac systems will malfunction pretty regularly since power surges are probably pretty common?

[skippedover]

If the system is now operating properly after re-programming the control, then I'd say the tech is covering the butt of the original installer who most likely mis-programmed something. Unfortunately, not everyone can be an expert on all the systems controls out there these days. So as long as it's fixed and operating properly, I'd just take what was said with a grain of salt and enjoy the new system. Normally if there's a power surge that affects a digital control, the result is a blank screen. Mind you, I said normally.

[chuckcrj]

You said in your first post that the air felt weak. Does it blow more now? May have had the airflow set too low and was cycling off hi head pressure like someone else said.

If he was talking about airflow settings getting changed from a power surge, I would say that is highly unlikely.

[ADD2010]

You said in your first post that the air felt weak. Does it blow more now? May have had the airflow set too low and was cycling off hi head pressure like someone else said.

If he was talking about airflow settings getting changed from a power surge, I would say that is highly unlikely.

Yup the air flow originally was very weak and actually it seemed sometimes there was no air blowing at all even when the heat was "on". After the tech came to fix it, the air flow is strong now, seems like it's now working how it is supposed to.

The tech this morning did not specify what settings would be affected by a power surge, he just said that the circuit board settings could get "confused" the same way other electronics get messed up when there is a power surge...but I haven't had any problems with the electronics in my house so I kind of doubt power surges are a problem.

I'm thinking that skippedover was right, that he was probably covering the butt of the original installer who is less experienced and maybe unfamiliar with this unit...woops.