HELP- NO SOLUTION FOR COMPRESSOR LOCKOUT

I am still having problems with my compressor locking out. After my system runs for an extended period of time, the compressor will lockout and the auxillary will kick on. My technician has done the following things: Replaced the CXM board twice, cut JW3 - this was not done originally yielding a low water temp problem, installed a hard start kit on the unit, flushed the ground loops, replaced air filters, installed a toggle switch to disengage the desuperheater during extreme cold, recalibrated the refrigerant pressure temperature settings, check for high low pressure problems - there was none. What in the world is going wrong ? After a few successful hours after the aforementioned interventions the system is still locking out per the descirption above. Is the heat pump an inferior product ? Comfort-Aire by Heat Controller. System specs: 4 ton unit with 4 150ft vertical bore holes for a 2200 square ft house. 1 circulating pump circulating fluid through the loops. PLEASE HELP !

 

Does the unit lock out on a fault or does the compressor quit running?
Do you have loop temps and air temps?

 

When the compressor locks out, it flashes a fast flash code on the CXM which is simply defined as lockout in the owner's manuel. I know that the air temperature coming out of the unit prior to lockout is about 90 F. Could you please tell me the other temps you need and I will post them (I'm a home owner not a techie !). The installer said that the expanision valve was frosted up yesterday. What would cause this ?

 

[attachment=0:35mcf9e9]CMX board.jpg[/attachment:35mcf9e9]
You have to jumper the test pins to get lockout code.
Be careful High Voltage in the area!

 

Installer says that the pump is undersized for a 4 ton system, and is replacing the pump. Could this be the cause of a low temperature lockout ? How many GPM's should the pump be pushing for a 4 ton system ?

 

Yes, but check pressure and temperature drop across coax before replacing pump or you'll be wasting your time.

Recommended is 3 GPM per ton.

 

Tech is clearly flailing

 

We have narrowed the problem to a low water temp issue. Please tell me exactly what data I need to gather and what the acceptable parameters for that data should be for the system to function properly. I see a troubleshooting diagram for heating cycle analysis in my manuel. I agree that this has been lots of guesswork, and my patience are wearing thin.

 

I would start by verifying flowrate. It should be at or close to 12gpm. This should have been the first step in system diagnosis, but it seems it may have been bypassed. You also need to verify Entering Water Temp and Leaving Water Temp. If your EWT is in the 30s , that should be fine. Your LWT should be about 5-8 degrees below that. This should have been the second step. Then you should verify Entering Air Temp (as close to the unit as possible) and Leaving Air Temp (again as close to the unit as possible)You should see a gain of 20-30 degrees. This should have been the third step. I would ask your installer what values he got for these steps before he replaced boards or put gauges on your unit, If he does not know,call someone else

 

The system shouldn't be too sensitive to GPM per ton assuming EWT is OK (30+ is ideal). Unless EWT is borderline too low, it should work OK with 2-2.5 GPM per ton, or up to 4-5 GPM per ton, though that's likely a waste of pumping power.

Also need to be certain sufficient antifreeze was used and that system is configured properly for the antifreeze.

Lockout after a long run cycle may be caused by low EWT and / or low loop water flow. My WF Envision accepts loop water as low as 20 and cuts out at 15 if the board is configured for closed loop with antifreeze.

Measuring EWT is fairly easy if the unit was installed with Pete's ports.

 

I had issues with the antifreeze once, the supplier had accidently sold me the wrong kind. It was supposed to be 100% glycol, but it only was a 60% solution. Or do you have methanol?
Check with spectrometer, it should be a antifreeze protection down to 15F in northern climate.
Check if both circulations pumps are running, I had one of two going bad once and not enough flow. The pressure drop over the coax should give you hints.
Other possibility is that some loop are shut off (air), bent too much or fuse together incorrectly. Temp delta should give you hints.

 

You may want to go buy a cheap non contact temp gauge, Rayovac is a common unit, just aim at pipe coming in and leaving your unit to get digital readout of EWT/LWT, can also get EAT/LAT,will be close if not exact temp, this way you can monitor you system at start up and during run to see how low your temps get and temp at lockout. handy tool for lots of things like finding heat loss spots in you house or how hot your car engine is running. I think most auto parts stores and sears sells them. Good luck.

 

Better for waterlines is a digital meat thermometer checked in ice water (should read 32).

Wrap its probe in a couple folds of aluminum foil and tape tabs of foil to pipe of interest. Lay on some insulation for better accuracy

There are several issues with cheap IR thermometers - they don't actually read just the spot lit by the laser, and variations in emissivity between materials affects accuracy

 

I use the IR for allot of things, what you said is true, but placed close to pipe the target is small, and will read apples to apples (copper in and copper out) pretty good , it is also fast, in two seconds you will know the temp in and out right now. One more thing Curt how would your wife like it if you poked 50 holes in your living room ceiling looking for cold areas with a meat thermometer? :mrgreen:

 

I'm fine with IR for checking individual registers, etc, as long as the user is aware of the limitations imposed by colors, materials, and the unit's focal ratio

 

OK, Here is the latest on my situation - The original pump for the system was undersized according to my tech. He says original (1 pump) was sized for 3 ton system. He replaced it with a two pump mechanism that is supposed to be pushing 12 GPM for my 4 ton system. When he did this, he flushed the system, assured me that the loop fluid was 38% glycol per owners manuel and measured an EWT of 39 F and a LWT of 34 F. The system ran as good as it has run since the fall from about noon on Monday until Tuesday morning. My wife attempted to raise the heat from 66 to 68 after waking and the compressor locked out. My wife cut the system off during the day. When I got home and turned on the system. It locked out after running for 3 minutes or so with a fast flash. I noticed that the compressor seemed to struggle when it began running, and I also noticed a slight hissing sound. My next step was to "shock" the system per tech's advice I turned off the unit for about 1 min. ran AC for 1 min. and then turned off for 1 min. After doing this I turned the heat on, the compressor ran strong for thirty minutes or less and the temperature of the room raised from 66 to set temp of 69 before cycling off. Any ideas about why I locked out today

 

OK, Here is the latest on my situation - The original pump for the system was undersized according to my tech. He says original (1 pump) was sized for 3 ton system. He replaced it with a two pump mechanism that is supposed to be pushing 12 GPM for my 4 ton system. When he did this, he flushed the system, assured me that the loop fluid was 38% glycol per owners manuel and measured an EWT of 39 F and a LWT of 34 F. The system ran as good as it has run since the fall from about noon on Monday until Tuesday morning. My wife attempted to raise the heat from 66 to 68 after waking and the compressor locked out. My wife cut the system off during the day. When I got home and turned on the system. It locked out after running for 3 minutes or so with a fast flash. I noticed that the compressor seemed to struggle when it began running, and I also noticed a slight hissing sound. My next step was to "shock" the system per tech's advice I turned off the unit for about 1 min. ran AC for 1 min. and then turned off for 1 min. After doing this I turned the heat on, the compressor ran strong for thirty minutes or less and the temperature of the room raised from 66 to set temp of 69 before cycling off. Any ideas about why I locked out today

 

I just replaced

The FP2 thermistor on a Heat Controller last week. You need the manuals to make sure the Tech has all the information he needs. I have them, but am out of WWW range for long periods of time, (if your system is not working). As a pro contractor I have very good response from the tech guys in Jackson, MI.

If you can not get them or the tech can not get them call me and I will get you what I have. A good ohm meter is needed to test the thermistors.

 

I am not a tech so go easy if I am way off base, but I think I may have had an epiphany :shock: . Am I correct in understanding that the FP1 and FP2 thermistors communicate the said faults to the CXM ? If this is the case, then considering that I had 3 possible causes for an FP1 fault: air in my loops (low water flow), undersized pump for the 4 ton system (low water flow), and the JW3 was not cut for the glycol antifreeze in the loops (improper temperature limit setting). Shouldn't I have been getting an FP1 Fault Code 4 when the compressor locked out ? It has locked out too many times to count after longer runs and in extreme cold temps. Of all those lockouts, CXM consistently flashed fast - no fault code. The tech said he got an FP1 Fault Code 4 flash once. According to the troubleshooting guide, fast flash has 3 possible causes - compressor overload, no compressor operartion, control board. When the tech and I initially went through the troubleshooting flowchart it pointed to bad CXM which we replaced twice. So my point is that all things considered above could there be a problem with the device that communicates to the CXM - the thermisoter ? We have addressed the 3 FP1 causes above, and the system is performing much better, but it still locks out within a 24 hour period. This can be reset by kicking over to AC and "shocking" the system before returning to heat. Could bad thermisoter cause this ? Temps at start up after flushing loop yesterday: EWT 39 F / LWT 34 F.

 

Lobby has a nice tag line

It is about measuring.

I knew we had a pond side loop leak, so when that was fixed, and the unit was still locking out and giving me an 8 code for poor plumbing, I pulled the wires out of the thermistor by accident.

I was having a bad day at that point so I could not test the thermistor without the wires attached. I know that climate master and heat controller use the same coil max chassis that everyone uses, so I got a Climate master thermistor for the Heat Controller product.

It worked fine. Before one orders thermistors one needs to test them with a good meter, before pulling the wires out of the sensor. I tend only to change one thing at a time so I know what happened. Must be old age.