Ontario 5 ton Geo running 24/7

Discussion in 'Maintenance and Troubleshooting' started by Maurice Sabourin, Oct 21, 2015.

  1. mrrxtech

    mrrxtech Member

    If the Freon charge is determined to be the same as when the Unit was installed, then there must be air in the loop due to the leaking glycol.
    That could cause a change in unit performance.

    Maurice, has this problem been repaired or is it still running your Unit 24/7?
  2. Maurice Sabourin

    Maurice Sabourin Newbie but learning quicly...

    the problem as not been fixed, it is still running 24/7 even at 32f outside.
    They came and "burped" the loop last fall, so there should be no air in the system.

    on top of it, the 2 ton locked out twice so far.

    they checked all levels and say they are within "charts"

    I fear I have been screwed royally of 43K$

    my parts and labor warranty is up next December. I hope they will find to problem by then.

    I relay don't know what to do...
  3. mrrxtech

    mrrxtech Member

    What did the 2 ton unit lock out on? As folks here will tell you, you need to put the unit into the test mode and check the code flashed by the Green LED on your controller card.

    If you have the owners manual, look at the schematic of the controller card for two small copper leads sticking up off of the board. The technicians short out the two leads for 2 seconds or less, listening for a click and the Trouble Code LED will stop continuously flashing and begin flashing a code. The number of flashes will repeat and can be deciphered using the Trouble Shooting table that came with you Unit.

    Having a Unit run for 24 hours a day will wear you down mentally & worry you to death, not to mention an unnecessarily high electric bill, so you need some help.
    I'm not a certified installer but I have a knack for solving problems.
    If no one else chimes in to help you figure this out, which I'm hoping they do, I'll stick it out with you until the problem is solved.
    I will say I have a knack for figuring out how things work and why they don't work.
    I also have a natural talent of finding things that are lost, but that's another topic.
  4. mrrxtech

    mrrxtech Member

    I'm assuming you have had some basic electricity training in the past and know how to work around energized equipment safely.
    If not, you need to get a referral for someone who is considered the Best in your area in Geothermal problem solving.
    There is 220 vac in the cabinet so this isn't the time or place to learn about basic electricity safety.

    If you have a way to check the lake/ground loop volume, like a surge tank used with some geothermal flow centers, have you seen a slowly dropping level in the loop?

    I have heard flow noises in my lines going to the loop pumps, when first starting up the system, due to air in the lines. Can you hear noises in the lines to and from the flow center/pumps?

    If you have 2 series ground loop pumps, are they both running?
    Last edited: Feb 27, 2016
  5. Maurice Sabourin

    Maurice Sabourin Newbie but learning quicly...

    2 ton:
    according to the manual the 2 ton locks out over high pressure, no reason in heating mode, the filter is clean. they changed the board the first time. they reset it after the last lock out, now waiting to see if it will do it a third time

    5 ton:
    the techs are pushing the running 24/7 is normal, that the house is leaking, that the basement is not insulated, that the pond is too cold... blah blah blah...

    the house is better insulated then first installed, and it worked fine the first 2 years. the pond is spring fed, never freezes, the basement is the same as before, the windows have all been sealed... like I said.... blah blah blah...

    the fact is that the SAf was 98F and now is 87F with a RA of around 66F now good reason for a SA to drop 11 degrees F in two years of running.

    yes I have electrical training and I am starting to understand HVAC...
    thank you
  6. mrrxtech

    mrrxtech Member

    I believe you have two problems, they are the hardest to troubleshoot.

    One problem is in the loop, causing loop reduced flow. The glycol leak you have will form an air bubble at a high point in the system. If you have a stethoscope or listing device, listen at the pump header or high point for air noise. I have an air removal float valve device at my pump header at the high point in the loop, and a surge tank I can make up to on my own. Air is continuously vented from the ground loop when air bubbles become large enough to move in the loop.
    After time with no leaks, there has been a need to add coolant.

    The 2nd problem is in the control system. The y1 24 vac signal for keeping the compressor contactor energized should drop to 0 volts from the thermostat when the set point temperature is achieved. If that isn't happening, there could be a "sneak path" for 24 vac from a failed board component or wiring change someone made while trouble shooting.

    You are 100% right, the unit should work exactly as it did when new, but a problem or two has been introduced over time. Those issue can be corrected without changes to the original design. Don't allow major work on the system like a compressor change out, the unit belongs to you, so keep easter egging by replacing major components to a minimum. An example was when the auto shop wanted to change out an AC compressor in my new vehicle. I told them to shut the hood, I'm leaving. I found the Freon leak at an auxiliary evaporator, tightened the hose clamp and added Freon fixing the problem.

    Here are some additional causes for compressor high pressure in the heating mode, from the Carrier owners manual:
    1) Reduced or no air flow. I would check the return air filter and the return air registers for a cause of Reduced air flow.
    2) Air temperature out of range. Check the return air temperature for abnormally low conditions.
    3) Bad High Pressure switch. Not likely or the unit would more than likely trip repeatedly on HP.
    4) Overcharged with refrigerant. That would have been seen by the Technicians, so I would rule that out if the charge was within specifications.
  7. mrrxtech

    mrrxtech Member

    The one thing common to all of the Thermostat you have used is the 24 vac transformer in your unit. It provides the power and output signals (Y1, Y2, G, etc) that operate your unit. As I said in the Carrier Trouble Shooting thread, the 24 vac transformer in the unit I was working on had been fried by a loss of one of 2 220 ac lines.
    If you have had some electrical issues on the grid, and who hasn't, you could have a degraded 24vac transformer. No Thermostat change out will fix that problem.
  8. geoxne

    geoxne Active Member Forum Leader


    Since the beginning of this thread responders have been pointing you in all different directions for a solution. I suggest you or your technician go back to square one for a proper diagnosis. It is possible you have more than one issue to deal with. Proper procedure and testing must be followed for a successful resolution.

    Nordic has a fairly comprehensive manual that is fairly easy to follow here-

    Proper Procedure-
    1-Verify source flow and temperatures are in range
    2-Calculate HE and/or HR and compare to manufacturers capacity tables
    3-Verify all control board and circuit operations
    4-If HE or HR is more than 10% off capacity tables with proper water flow and temperatures, and control circuits are correct, only then test and diagnose the refrigerant circuit.

    As mrrxtech said, 2 problems are hard to troubleshoot. Intermittent problems are even harder.

    My observations based on very limited operational data-
    -It is very possible the heat load on the 5 ton unit is greater than its capacity. This would easily explain long run times during high load periods.
    -Verify the 5 ton unit is actually engaging 2nd stage. One poster on this site recently discovered, after a year and a half, the wiring to the 2nd stage solenoid was disconnected. If the fan upstages and the compressor does not, LAT will drop.
    -Two flowcenters with two HP's on one loop field is not a typical installation. If check valves are not installed on parallel pumps, water will short circuit through the HP that is not running. EWT on the HP that is running will drop rapidly.

    If you get some data follow this check list and let us know.
  9. geoxne

    geoxne Active Member Forum Leader

    Also, regarding check valves with parallel pumps. Even if check valves are present they can get stuck open or closed. A reverse high pressure purge can jamb a spring check closed.
  10. mrrxtech

    mrrxtech Member

    Good advice geoxne.

    I tend to believe the system was designed correctly since it worked for a year or more with no problem. A problem or two has been introduced into the system to degrade it's performance, so using your checklist, will provide the data for evaluating the problem.

    The 5 ton unit that appears to be running continuously needs to be checked to see if the compressor is actually running (the high electric bill evidence was provided) but, like the Carrier unit, when it locks out the fan runs in high speed which is more than likely is for the emergency heat source which doesn't exist.
  11. docjenser

    docjenser Well-Known Member Industry Professional Forum Leader

    Guys, follow the basic steps here, it really not that hard.
    simply stick a thermometer and a pressure gauge in the p/t port and you know temperature and flow of the loop, and the heat extraction, which tells you if the refrigerant circuit is OK.
    Change in supply air temp can have many reasons and is not very telling right now. Do you have check valves at each circulation pump. What compressor stage is the compressor running?
    Also a pond which does not freeze cannot be too cold, by definition.

    Follow geoxne's list.

    The rest of the advise here is speculation, not very helpful without meaningful data.
  12. Maurice Sabourin

    Maurice Sabourin Newbie but learning quicly...

    There are check valves installed, on the "out" side of the flow centers near the units.

    when they first installed the system they had one flow center for the loop and an extra circulation pump near the 5 ton unit... that did not work, so they added an extra flow center... this shows inexperience with a dual system and single loop, IMO...

    please tell me what extra data you need I will try to get it for you.
    the work order have some data on it that may be useful.
    According to the techs, the numbers are ok and are within chart numbers...
    I am would like to check them myself to see if maybe they missed something

    Side note...
    I have increased the fan speed from low to medium then to high... the RS increased and the SA stayed the same... the system still does not shut off...

    question... if the return air temp stays constant and the compressor is running is the supply air supposed to vary... IE: I have seen the supply air go from 87f to 81f and back up again while the compressor is running at stage 2... is that normal?

    thank to all for your help...
  13. Maurice Sabourin

    Maurice Sabourin Newbie but learning quicly...

    I have

    I have checked the voltage on both Y1 and Y2, when the unit is running on second stage, both Y1 and Y2 are reading 26 volts AC.
  14. geoxne

    geoxne Active Member Forum Leader

    Helpful data according to check list I posted above.

    You may be getting voltage at Y2, but that does NOT confirm the compressor is running in stage 2. That has to be confirmed with a clampon ammeter to observe compressor amp difference between stage1 and stage2.
  15. Maurice Sabourin

    Maurice Sabourin Newbie but learning quicly...

    Air bladder tank...
    Looking at the manual I noticed the use of a Air bladder tank... My system has none, how important is that?
  16. Maurice Sabourin

    Maurice Sabourin Newbie but learning quicly...

    Source flow temperatures.

    I have attached the two thermometer probes to the brass fittings inside the 5 ton unit with zip ties and replaced the insulation on top.
    the readings are 35.9f and 39.9f
    unit is running stage one
  17. mrrxtech

    mrrxtech Member

    The bladder tank would act as a make up volume for any loop leakage, or stubborn air bubbles that finally flow out of the ground loop.
    If your flow center is the type that has a return tank, then you don't need a bladder since you can make up to the tank as the level drops due to air bubble removal or that leak you mentioned.

    The pressure differential across the water side heat exchanger that Docjenser mentioned taking a reading on, can be converted to flow using the tables that came with your owners manual, which will tell you if the loop flow is low.
    If the flow is low, you will have to identify the cause of the low flow. Is it a pump issue or a flow path issue due to an air bound loop.

    The failure of the 5 ton unit to shut down is a different problem, assuming the Thermostat is satisfied and the compressor is actually running (y1).
    This may be a repeat fact but Carrier ECM/Fan card has the yellow LEDs that show the status of each input from the thermostat starting with G for the fan, Y1 Compressor start, Y2 2nd stage of the compressor, O for the reversing valve for swap to heating, and W for Emergency Heat.

    It's possible that your unit(s) use the same ECM card or a similar card with the quick check LEDs for input status. You can avoid using a meter to check if the input is present.
    Since I played Junior Welder last week checking a bimetallic fan switch in my propane furnace, my appreciation for how much energy is present in 24vac when shorted to ground has been renewed. I was working in the semi-dark and pushed the probe onto one terminal, then continued in until I touched the sheet metal behind the switch. The momentary touch took a chunk out of my probe.
  18. Maurice Sabourin

    Maurice Sabourin Newbie but learning quicly...

    There is no tank anywhere on this system... installation cost savings?

    I will order a pressure gauge to check the loop pressure levels .
  19. mrrxtech

    mrrxtech Member

    My Brother insists on having a place to check loop level/volume and a way to makeup for loses or air removal over time. He had me designing sight glasses and surge pipes on the first floor with the unit in the basement, when we started discussing installation. I admit that the surge tank with pressure gauge and air removal device saved me this heating season. I heard air rushing into the loop at the air removal device, each time the unit shut down. It turned out that I had a void forming in the system.
    I added the water/antifreeze mix with my swimming pool pump/flush cart until the 2 gallon bladder tank filled and the system pressure went to 20 lbs then stopped. My unit has a 25 lb heat exchanger pressure limit. The loop took in the water from the bladder tank and pressure was at 5 lbs until the unit was started, then it slowly dropped to zero after a few minutes.
  20. Maurice Sabourin

    Maurice Sabourin Newbie but learning quicly...

    I cant play too much with adding stuff on this system until the parts/labour warranty period as run out. or they will use it as an excuse to cancel it. but I wish they would have added monitoring devices, a bladder tank and flow meter to the loop. so I could monitor the system properly.

    right now all I want is the system to stop once it reaches call temp...

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