Water Furnace Red Light Freeze protection

Discussion in 'Maintenance and Troubleshooting' started by mm99, Jan 22, 2011.

  1. mm99

    mm99 New Member

    I run open loop and have been getting occasional Red Lights lately. I ran tests and outgoing water was near freezing. Water in 48 Water out 31.7, AIr in 72 Air out 94.
    I ran a descaling solution through, as this had not been done in several years.

    Now the problem is worse in that the furnace goes to red light even quicker. The flow rate is the same its been for years the problem is the very low water out temerature and I was wondering what, otehr than flow rate problems can cause this. Can refrigerant leaks or compressor failure cause this? Seems unlikely. but if there can be otehr issues then it may be time for me to call in the cavalry. Question is do I call HVAC or plumber?

    Any Thoughts, ideas, suggestions?

    ...Ray
     
  2. engineer

    engineer Active Member Forum Leader

    Water out at 32 is too low for open loop. The system will (rightfully) lock out following 3 incidents of refrigerant temp leaving the water coil at less than 30*F for more than 30 seconds.

    With 48 EWT and 32 LWT, good heat exchange is taking place, but if just a bit of icing gets going (likely at 32*F) the resulting insulating effect and flow restriction cause it to "snowball" (pun intended)

    Raise water flow until LWT is 36+
     
  3. mm99

    mm99 New Member

    Help with diagnosing water flow problem in the input circuit to the furnace

    Thanks that is what I figured. Last night I tired to de-scale the water feed circuit from where it comes into the house to where it enters the furnace.

    This am I ran flow test as water comes in from well (10++ Gals / Min) and at entry into furnace (5 gals per min). All conducted from a full pressure tank at 60psi with pump off (that eliminated the pump from the equation).

    So which of the following devices can be causing a flow restriction?

    I have an old water meter and a braukmann D05 valve plus a shutoff valve near the furnace. I suspect one of these devices is obstructed?

    I took the Braukmann apart and it all looks good to me and its not a flow restricter but a pressure valve (honestly I don't understand how it does its work).

    I do feel some Iron bacteria deposits in the back chamber though if that matters. No matter how I adjust it the flow rate does not change so I suspect problem is upstream (but I am open to suggestions on diagnostics and remedy.

    I am grateful there is a forum like this one though.

    ...Ray
     
  4. mm99

    mm99 New Member

    Removing the flow meter (a used water meter) upped the flow rate and my return temperature is now 42 degrees. WooHoo. The Taco valve is leaking though :(

    We've been running on backup resistence heat for the past couple of days. This morning it was 65 in the house. Until now I did not know that the backup heaters were not powerful enough to handle the coldest of days on their own.

    Need both running to keep the house comfortable.
     
  5. engineer

    engineer Active Member Forum Leader

    Glad to here you worked that out.

    Now you may be able to bring the flow down a bit - shoot for 36-38 so as not to waste excessive well pumping power
     
  6. mm99

    mm99 New Member

    Thanks engineer, I'll do that.

    However, I've gone down a few times now and I am not sure if the furnace is cycling correctly.

    Given the outside Temps are exceptionally cold today, it seems weird for it to to be going for only 3-4 minutes and then off for 2-3 minutes.

    I don't think its firing up the second stage either.

    Its a circa 2005 Water Furnace Premier 5 Ton.

    Are these cycles learned by the board from previous experience? This would make sense

    Should I reset something? All I have done lately is turn the breakers off and back on. Furnace has been on Emergeny heat for the past few days while I diagnosed teh water supply issue.

    Also the time between taco valve running and compressor firing up is too long. Its wasting a ton of water. Can that be fine tuned?

    I will post as a separate thread in case someone else wants to respond.

    Thanks for your help.

    ...Ray
     
    Last edited: Jan 23, 2011
  7. mm99

    mm99 New Member

    Blower vibration problem

    My WF Premiere incorporates Blower in upper chamber and resistance heat above that.

    There is a point at which the blower is running relatively slowly and compressor is not yet on and the vibration is alarming.

    Once the blower speeds up the vibration is dramatically reduced. When its idling it does not vibrate, its at the in between speed that something is vibrating a lot.

    I did a quick check and the blower was clean and the motor was not loose on the bearings but I think I need to do a more thorough check. Need to know what to check for.

    There may be a loose bolt on the back side but I don't know how to gain access to that side of the machine since there is no access panel.

    Is there a common problem with the blower unit becoming loose or should I make a more thourough check of the bearings.

    Any ideas or seggestions?
     
  8. mm99

    mm99 New Member

    WF Cycling strangely help?

    MY WF Premiere circa 2005 with WF Thermostat. Open Loop, forced air, 5 Ton, 2 Stage compressor.

    I re-started by turning off breaker.

    Machine runs blower for 5 mins
    @ 6:33 Compressor
    @ 10:53 Compressor Stop
    @14:29 Click ? Getting Taco Valve going??
    @15:24 Compressor on
    @20:27 Compressor off

    This is what I was getting before re-starting the unit. I find this cycle strange. Will it settle down over time?

    Furnace had been getting close to freezing point due to poor water flow but I fixed that today. Do I need to reset something on the board so that it forgets previous freezing prevention cut outs?

    Its unusually cold today so I don't get why the machine is taking 5 minutes to cycle or why its not running a lot longer before taking a break

    Also its s 2 stage machine but I don't hear a transition to the second stage unless its already there.

    The Aux heat is kicking in and but we are staying 2 degrees under set temperature.

    Water in 49-50 Water out 39.

    How does one adjust these cycles or reset this furnace to behave better?


    ...Ray
     
  9. Forum Admin

    Forum Admin Administrator Staff Member Forum Leader

    mm99,

    I merged your threads
     
  10. mm99

    mm99 New Member

    Wished you hadn't seeing as they are different topics (which is why I made them separate threads.

    IMO Makes it easier for others to review without having to read about other unrelated issues. Also easier for those googling for a particular problem.

    But hey I am new here and if this is how you do it in Rome then I'm good with it.

    ..Ray
     
  11. Forum Admin

    Forum Admin Administrator Staff Member Forum Leader

    They may appear to be separate topics but they are apparently all related to your system. It will be easier for the members to help you using one thread for all your system issues.
     
  12. engineer

    engineer Active Member Forum Leader

    Agree with Phil on organization...next time post all problems in a single thread with small paragraphs...now on to the technical issues raised:

    1) Water temps are fine

    2) on for 3 minutes and off for 2 is inefficient and hard on unit. CPH (cycles per hour) thermostat setting may be causing this...reduce it.

    3) My WF Envision asks for water just a few seconds before compressor start, likely to get the loop pump started and up to speed before compressor current inrush.

    4) Are all those @ times minute-seconds or hours-minutes?
     
  13. mm99

    mm99 New Member

    Maybe but the only yhe one I posted separatly got responses from others

    We'll have to agree to disagree but I think more granular and problem-specific (as opposed to user-specific) threads is better. But not everyone will know how /when to do that.

    Consider this. I experimented and re-posted a copy of the thread on cycling.
    The shorter, more precise thread got responses from 2 other users.

    The now long winded thread is now only being monitored by those who feel they have invested in it. In this case its only you engineer (which btw I very much appreciate) :)

    Thanks for your help

    ...Ray
     
  14. mm99

    mm99 New Member

    Cycling solved

    Turns out the cycling was being caused by a failsafe pressure switch (pu there years ago by the installer of the original WF) that kicks in at 30 psi and allows the well pump to recover. I think it does this by interrupting the signal to the system that the Valve is fully open.

    Its clever but caused confusion, sorry bout that. I think we are too close to the Pump capacity and also the well capacity that the system requires this failsafe.

    On most days it works though in that we never fall 2 degrees off and call for aux heat. Although you do have me worried about wear and tear of shorter cycles.

    Q1. Alternatives where well capacity may be 12-15 Gals per min?

    Q2. What is best, most durable, biggest bang for the buck pump for Open Loop and why?

    I don't want to mess with pumps/wells for now so I hope I can crawl through winter this way and make changes in the spring.

    The furnace tech also found that strip#2 had a burned out connector and that in supplementary heat only Strip 1-2 are called for while in Emergency heat all 4 strips can be called.

    Q3 Should I be worried about the burned out connector?

    Short cycles and 1 5kw strip was not enough for the very cold days we just went through.

    The numbers btw were in Minutes and Seconds.

    Thanks for your assistance.

    ...Ray
     
  15. engineer

    engineer Active Member Forum Leader

    That's unfortunate - short cycles greatly reduce system efficiency and are hard on the unit.

    I can't recommend well / pump improvements - very site specific.

    Since your well is marginal you may want to consider retrofitting a closed loop. Closed loop circulators use far less power than most well pumps to move the same amount of water.

    A closed loop with antifreeze would relieve your freeze lockout issues as well - Unit could be configured for loackout at 15 rather than 30 degrees F.
     

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