Goodman 2 Stage Heatpump P3 and C3 errors

[penderhvac]

I have a Goodman 18 SEER heatpump, 2 Stage Gas furnace and a CTK04 communicating thermostat in my new home.

At the end of the summer the tech was out to check the system operation. He had turned the cooling down about 5 degrees below room temp and was checking charge. We were outside kibitzing and the unit shut off. Thinking it had had reached setpoint I went back inside to turn temp down some more.

What I saw was the temperature was still 2° from set point, the display indicated the unit was “on” and the equipment status was showing both stages running and fan on. However noth8ng was running. I went back outside and the Tech had spotted a C3 status on the display inside the outdoor unit, “Cool Mode Short Cycle Timer” . Since the unit had been operating for 30 minutes this seemed strange.

He was stumped so poked around and did not find much and said to call if problem came back. Since then we have not used the cooling so no issues.

However we are now in the heating season and we are seeing P3 errors, nothing running and the thermostat showing everything is running. These errors show up after the system has been pulling for a long time, typically over 30-40 minutes.

After a few minutes the system will start running again.

It seems to happen both on Stage 1 and Stage 2.

There are no errors showing in the diagnostics logs.

I have a tech coming sometime next week( really cold snap so I did not push him as a lot of emergency no heat calls).

Since he was unfamiliar with this error, I am looking to see if anyone has seen this occur and some possible reasons I could gently suggest to him.

I have no intention of trying to fix this myself as it is still under the 1 year builders warranty.

[Bazooka Joe]

Off track a bit, but did anybody register your system, as manufacturers warranty decreases significantly if never registered.

Did you get any rebates, as at 18 SEER and if your furnace is 95%> probably would qualify.

Also that thermostat ( CTK04 ) needs to be installed with a Goodman communicating system in order to get the Goodman 10 year warranty on that thermostat, guessing your system is communicating.

[penderhvac]

Thanks for the tip. Yes everything was registered. By HVAC contractor. I also used the warranty check on the Goodman site to verify.

I asked Goodman about the thermostat and was told no need to register it specifically as was part of the system. This came up as I could not find any serial number on it.

I guess I should follow up on the CTK04 to be sure.


Tim

[Bazooka Joe]

Thanks for the tip. Yes everything is registered.

I asked Goodman about the thermostat and was told no need to register it specifically as was part of the system. This came up as I could not find any serial number on it.

Tim

Yes I changed it prior to your response to say the equipment needs to be registered and be Goodman equipment and communicating in order to get the 10 year thermostat warranty.

Rebates from your state ( if you have them ) , local utility company or gas company should apply to your system if they installed AHRI matched systems and meet a certain SEER and EER and furnace efficiency.

Did anybody tell you about them?

[penderhvac]

No rebates were available in Delaware.

[Bazooka Joe]

No rebates were available in Delaware.

https://www.dsireusa.org/

Did you check here?

https://www.burnsandmcbride.com/energize-delaware/

https://www.burnsandmcbride.com/wp-c...v01_030419.pdf

Sorry I do not have an answer to your question, just the registration and rebate thing...

[penderhvac]

One more bit of information: It is doubtful that this is caused by a defrost timer. As the outside air was 45*.

[beenthere]

One more bit of information: It is doubtful that this is caused by a defrost timer. As the outside air was 45*.

When was this system installed.

[Bazooka Joe]

If they install systems like these they should be versed in troubleshooting these types of system, class room trained as an example, no?

Hopefully they send a more seasoned Tech. that is trained/versed on your unit model and can put it through the different scenarios.

Worst case have them call Goodman Technical Support.

[penderhvac]

I closed on 5/2/2019 so it is still within 1 year builders warranty.

[penderhvac]

If they install systems like these they should be versed in troubleshooting these types of system, class room trained as an example, no?

Hopefully they send a more seasoned Tech. that is trained/versed on your unit model and can put it through the different scenarios.

Worst case have them call Goodman Technical Support.

Yes one would hope that a Tech more experienced in communicating control systems would be dispatched. The one that was out in late fall started working for his dad's HVAC company at 16 years old and now I would have to put him at late 20's early 30's so he does have some experience but maybe not with the "new fangled" controls.

So I take it you have never run into this type of fault???? I have tried to Google it, but the results all related to a true short cycle not a "C3/P3 fault" after an hour of running. I hope they can get some help from Goodman if nothing jumps out tomorrow or Tuesday when they come to diagnose.

Thanks for your time responding to my problem and watching my back on the warranty registration.

[Bazooka Joe]

I closed on 5/2/2019 so it is still within 1 year builders warranty.

That builders warranty applies to the labor, the equipment warranty on the OD section says once registered and to the original owner you get a 10 years parts warranty, a limited lifetime compressor warranty to original owner, and if the compressor ever fails within the 1st ten years you get a new OD unit ( not a replacement compressor ) same thing applies on some model Goodman furnaces, they usually have a limited lifetime HX warranty, the standard 10 year parts and depending on model if HX ever fails within the 1st 10 years ( once registered ) you get a new furnace not a replacement HX. Did you know all that?

In regards to your question, I never installed the 18 ( up to 19 SEER ) unit that you have so I do not have any experience with that model.

If you reside in Quebec or California you do not need to register the products to receive the full manufacturer warranty.

Did these people do any type of commissioning of your system? Things like static pressure, temperature rise across HX , subcooling number, amperage draws of motors and compressor etc etc are within manufacturer specifications. Did they leave a copy at the job site? Ask them for one if it never has been done.

[penderhvac]

Thanks. Yes I did know about the 10 year warranty but thought that Goodman gave you a compressor. I had an Amana 18 SEER heatpump in my last house and was aware it had a new unit replacement policy but did not know the Goodman badge gave me the coverage.

I have not seen any baseline data from the install commissioning so that is something I need to ask about.

Many thanks and have a good week!

PS: If we get this mystery solved, I will post back so the information can possibly help the next guy.

[Bazooka Joe]

Thanks. Yes I did know about the 10 year warranty but thought that Goodman gave you a compressor. I had an Amana 18 SEER heatpump in my last house and was aware it had a new unit replacement policy but did not know the Goodman badge gave me the coverage.

I have not seen any baseline data from the install commissioning so that is something I need to ask about.

Many thanks and have a good week!

PS: If we get this mystery solved, I will post back so the information can possibly help the next guy.

You must have the GSZC18 as that’s the only 18 SEER Heat Pump Goodman makes

https://www.goodmanmfg.com/products/.../gszc18-dszc18

“product specifications” page one says once registered and to original owner lifetime compressor warranty, 10 years parts, and 1st 10 years if compressor ever fails a new OD unit.

Now depending on your furnace model number the same may apply, new furnace within 1st 10 years if HX fails, limited lifetime HX warranty after that and 10 years parts once registered.

Yes certain Amana models have the limited lifetime whole new OD unit if compressor ever fails. The ASZC18 Heat Pump being one.

[penderhvac]

We had the installer out this week to try and analyze/diagnose/fix the problem. ( Fortunately it is under 1 year builders warranty for parts and labor. )

After much head scratching, he was stumped. However he did check charge in Heating mode and found it was slightly over charged. During the check it did cut out on him however the sequence was a little different than what we caught in the cooling mode. What we saw was:
1. Unit running on P2 ( second stage)
2. Unit Stops on 0n ( standby ) and air handler stops suddenly, does not ramp down as it does in a normal stop.
3. Thermostat still 2* from setpoint
4. After a minute or so P3 error shows ( Heat Short Cycle Timer )
5. A few minutes later system starts in P2.

The other issue we saw was the compressor was drawing more amps than the spec sheet indicated at the 50* OAT.
The expanded heating data calls for about 10.4A (includes fan on outdoor unit ). We were measuring 12.5 after 20 minutes. Low speed is also a bit high Should be 7.7A actual is 9.1 .Yes meter is accurate as we crosschecked hes meter with mine.

The tech thought it may be the thermostat - a communicating CTK04AB- so that will be replaced when new one comes in.

More Details as they evolve next week.

Equipment involved: CTK04AB Thermostat, Goodman GMVC960804CN (propane furnace), GSZC180361CA (outdoor unit) and CHPF3743CBB coil. And Yes I did verify the registration and printed copies for my records.

[beenthere]

So did he correct the charge issue.

A new thermostat won't help if he didn't.

[pecmsg]

The only way to check the charge in heat mode is to pull it and weigh it! "Slightly Over" is guessing!

[pecmsg]

We had the installer out this week to try and analyze/diagnose/fix the problem. ( Fortunately it is under 1 year builders warranty for parts and labor. )

After much head scratching, he was stumped. However he did check charge in Heating mode and found it was slightly over charged. During the check it did cut out on him however the sequence was a little different than what we caught in the cooling mode. What we saw was:
1. Unit running on P2 ( second stage)
2. Unit Stops on 0n ( standby ) and air handler stops suddenly, does not ramp down as it does in a normal stop.
3. Thermostat still 2* from setpoint
4. After a minute or so P3 error shows ( Heat Short Cycle Timer )
5. A few minutes later system starts in P2.

The other issue we saw was the compressor was drawing more amps than the spec sheet indicated at the 50* OAT.
The expanded heating data calls for about 10.4A (includes fan on outdoor unit ). We were measuring 12.5 after 20 minutes. Low speed is also a bit high Should be 7.7A actual is 9.1 .Yes meter is accurate as we crosschecked hes meter with mine.

The tech thought it may be the thermostat - a communicating CTK04AB- so that will be replaced when new one comes in.

More Details as they evolve next week.

Equipment involved: CTK04AB Thermostat, Goodman GMVC960804CN (propane furnace), GSZC180361CA (outdoor unit) and CHPF3743CBB coil. And Yes I did verify the registration and printed copies for my records.

Consider getting a Certified Contractor out too review the entire install. It will cost a few bucks but can save many more down the road.

[penderhvac]

So did he correct the charge issue.

A new thermostat won't help if he didn't.

I agree it probably is not the thermostat since it is both a cooling and heating issue and the transition from P3 to standby shuts the blower off immediately and does not use the ramp down profile. However I don’t know Honeywell’s logic so that is just an assumption.

He only took out a few oz and pressure went from 405 or so down to 386 on the hot side and now is at 116 on the cold side. While these are not exactly what the chart calls for, it is pretty close.

As far as I can tell the charge was corrected. Here is a shot of the inside chart. Attachment 813047

[pecmsg]

I agree it probably is not the thermostat since it is both a cooling and heating issue and the transition from P3 to standby shuts the blower off immediately and does not use the ramp down profile. However I don’t know Honeywell’s logic so that is just an assumption.

He only took out a few oz and pressure went from 405 or so down to 386 on the hot side and now is at 116 on the cold side. While these are not exactly what the chart calls for, it is pretty close.

As far as I can tell the charge was corrected. Here is a shot of the inside chart. Attachment 813047

Get an independent contractor to advise.