Minnesota Waterfurnace Envision Low pressure compressor light

Discussion in 'Maintenance and Troubleshooting' started by eth555, Dec 22, 2014.

  1. eth555

    eth555 New Member

    I have a 3 ton Waterfurnace Envision split system that the installation was completed in the fall of 2013. It has performed great and has been saving me a lot compared to the old fuel oil system it replaced. I am very happy with the system and the results it has provided so far. I have been a lurker on this forum since before making the decision to have this system installed.

    Last night I woke up at 2am to a cold house and when I went downstairs to check the system the low pressure/compressor status light was flashing red. I powered down the system and powered back up and it started and has been operating seemingly fine since; it has brought the house back up to temp and maintained the setting. I looked in the owners manual and it is vague on what to do in this situation. Should I not worry about this if the unit continues to operate seemingly normally? I am basically wondering at what point do I contact the installer and should I be concerned about what happened; or does this happened once in a while? It had been in operation for over a year without a reset; is it like a computer where it needs to be fully shut or powered down once in a while? Thanks for the assistance.
  2. engineer

    engineer Well-Known Member Industry Professional Forum Leader

    Do not equate this system with a computer whose operating system needs an occasional reboot. The analogy simply doesn't hold; the parallels aren't there. Low pressure implies a refrigerant leak, which sounds extremely unlikely since the system has run well since power cycled. Another scenario involves a severely iced evaporator, (we see that in summer cooling mode with restricted airflow or too low setpoints) but in heating mode that should have tripped the low water flow error condition first, IMO.

    That's conjecture; I haven't worked a system with that error in heating mode w/o it being a genuine refrigerant leak / loss of charge.

    I would contact the installer and have basic PM steps and measurements taken; in particular heat of extraction. Ask in advance that heat of extraction be measured / calculated and then compared to expected values for the specific system and its operating conditions. If the service manager or technician is ignorant or evasive about "heat of extraction" they are likely incompetent; find someone else.
  3. geoxne

    geoxne Active Member Forum Leader

    Low Pressure/ Comp fault on the Envision requires checking the Comfort Alert FIRST to see if that component is reporting the fault related to power (Maybe too many Christmas lights in the neighborhood?).
    Last ALERT flash code is displayed for 1 minute after module is powered on.

    If you feel comfortable looking inside-
    1) Power off at breaker
    2) Open unit door and observe location of Comfort Alert
    3)Power on unit and observe yellow alert led flash code on Comfort Alert.
    4) Close door (Tip-Unscrew latch several turns before tightening to allow latch to engage)

    If you don't have a flash code then look at low pressure issues. If you do, see the following and let us know. Also do you have an Intellistart?
  4. eth555

    eth555 New Member

    Thank you for your replies, it has been busy with Christmas this past week! I have not had the issue reoccur since last Sunday night-Monday morning. I am glad I should not have to worry about power cycling the unit like a computer. I did open the panel and the comfort alert was not flashing, after powering it up, and I do have Intellistart. My power coop allows me to track my power consumption on a daily basis, the geo unit and water heater on a separate meter, there has not been a spike in power usage. We have a cold snap that we are facing this week so it will be a decent test and if it happens again I will definitely contact the installer and have him look at it, as well as update here also.
  5. Mark Custis

    Mark Custis Not soon. Industry Professional Forum Leader

    I think you may have a very slow refrigerant leak.

  6. geoxne

    geoxne Active Member Forum Leader

    On the Envision, the "Low Pressure / Comp" fault led is shared with the low pressure switch and the Comfort Alert. It should be determined which has created the fault. In the procedure listed above in my previous post I failed to realize that you have a split unit. In that case low voltage power to the control board typically originates from the airhandler and that is the breaker that needs to be shut off and back on to read the "last code".

    If it happens again do not power off or reset until you check to see if the Comfort Alert is flashing a fault code. If it is, document the code and then reset. Then refer your installer to Tech Bulletin TB11091301 which explains rare and random faults in units with Comfort Alerts and Intellistarts.

    I do not think you have a refrigerant leak. All other potential causes should be checked before suspecting low refrigerant.
    Last edited: Dec 29, 2014
  7. eth555

    eth555 New Member

    Thanks again for the replies. I would think a refrigerant leak would repeat itself consistently. We are now in below 0 weather and seems to be running normally. If it does happen again I will get the fault code before shutting system down. Thanks for all the information!
  8. eth555

    eth555 New Member

    So my WF Envision has been running great since the lockout in Dec, until last night it did a lock out again. This time I checked the flash code and it was Code 7, I counted it many many times to be sure. Any ideas on what causes that code, I am glad it happens so infrequently. I see from the descriptions above it has to do with the thermostat with no current on run circuit? I have a Honeywell Prestige (I think that is what it was called) thermostat if that makes a difference. Thanks
  9. AMI Contracting

    AMI Contracting A nice Van Morrison song Industry Professional Forum Leader

    dunno the WF fault codes off the top of my head. I do know that we have lockout problems with transitional weather. Here in MI cool nights and warm days have people turning systems on when the home is not necessarily saturated with heat and cold RA temps may cause nuisance lockouts.
  10. eth555

    eth555 New Member

    AMI Contracting thanks for your reply, I guess I will not worry about it unless it becomes more frequent.

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