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PTAC produces cold air when on heat mode

Hello all!

I've been battling with my apartment's (condo, have my own combo boiler and water heater ) PTAC units (have two) since forever. One of the units is new and the other is old. Both from the company Islandaire. Both have not been producing heat and just blowing cold air. I reached out to Islandaire and they had a tech come out and put it new zone valve actuators. This was on Monday.

The tech left assuring me the heat will work now but didn't test it because he forgot I had my own boiler and thought we couldn't test it until the weather gold colder and the building "turned on the hot water." So, after he left, I turned on the heat and to my dismay, the air is still cold. I call him and he tells me to 1) turn both units to heat and set temperature to 90 and 2) get a hose and bucket to drain the boiler because the problem is most likely caused by air trapped. He told me to keep draining until the bubbles no longer appear in the bucket. Well, I've tried several times and the units are still producing cold air.

I'm really upset as I was hoping I'd have heat this winter and despite troubleshooting since summer and paying lots of $$$, the issue still exsits.

One note that may be helpful but not sure: when I take a shower, the water will go from hot to cold very quickly and then slowly get warm again. I remedy this by turning the water all he way off and then back on again. Similarly, when I was draining the water from the boiler, I'd touch the water and feel it hot and then warm and then hot again.

Any thoughts or ideas would be greatly appreciated.

Comments

  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 15,302
    @eva_needs_heat

    If the tech did his job correctly (installing the valves) then it is certainly possible the system is air bound. draining the water from the bottom of the boiler will not help.

    He needs to come back and bleed the system and you shouldn't have to pay for that service. You had a system full of water and no air when he started. He replaced the valves but should have put the system back to where it was when he got there including venting the system and testing the operation of the valves he installed. It's part of the job.

    He should have asked more question and realized you had a separate boiler before he started.
    bburdmattmia2HVACNUTEdTheHeaterMan
  • mattmia2
    mattmia2 Member Posts: 9,405
    Or there was and still is a problem with the boiler going in to heat mode and there is nothing wrong with the zone valve in the univent.
  • eva_needs_heat
    eva_needs_heat Member Posts: 6

    @eva_needs_heat

    He needs to come back and bleed the system and you shouldn't have to pay for that service.

    I don't mind bleeding it myself but even that isn't helping
  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 15,302
    @eva_needs_heat

    Anyone can bleed it. But you can't bleed it from draining the boiler. Air rises and collects at the high points of the system. There could be an air vent on the ptac coil
  • HVACNUT
    HVACNUT Member Posts: 5,737
    Can you post pics of the boiler and the PTAC's? Show the piping on the boiler.

    I'm assuming Islandaire installed the "new" PTAC and it hasn't worked right since? If that's the case, you shouldn't spend anymore than you spent for the installation. If you did, you should get it refunded.
    And after a new installation, it should be up to the client to purge loops. The tech had no idea what he was looking at. 
    Maybe ask to speak to owner, Robert Hansen. Be the squeaky wheel.
    EdTheHeaterMan
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 7,518
    edited September 2023
    Purging, bleeding and draining are all terms used in this profession to mean opening a valve to let something out. Knowing which valve(s) to open to get air out (most times called purging) is the key.
    It may not work if you were not opening and closing the necessary valves in the proper order. To purge air from a system, you should see air leaving the system thru the garden hose. If you are not getting any air from the garden hose, then you are not purging.

    . This illustration shows how NOT to purge this system. Water takes the path of least resistance which is not thru the PTAC coil.

    By closing certain valves you can direct the flow thru the PTAC Coils and get the water to move the air out.

    There may even be a manual air vent at the top of the PTAC coil under the cover for that purpose.

    If what you are doing is not working, then have the company that you paid to fix it, come out and make it work. When they are finished pay them with a credit card. That way if it does not work then you can file a dispute with the credit card company if the company does not honor their warranty on repairs.

    If you used a credit card (Not a DEBIT Card) for the last repair, then file a dispute with the card company with a list of all your transactions and the fact that it still does not work. You would be surprised what a vendor will do to keep from having a chargeback from a card company. Too many charge backs and they get a higher % rate for accepting cards.


    Edward F Young. Retired HVAC ContractorSpecialized in Residential Oil Burner and Hydronics
  • pecmsg
    pecmsg Member Posts: 4,680
    You do not have a PTAC you have a Air Handler. The building supplies hot water or cold water depending on the time of the year.
    EdTheHeaterMan
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 7,518
    edited September 2023
    pecmsg said:

    You do not have a PTAC you have a Air Handler. The building supplies hot water or cold water depending on the time of the year.


    Look at this @pecmsg
    You might change your mind.
    https://islandaire.com/ptac/product/ez5r/
    Also @eva_needs_heat has her own boiler in her unit. Not exactly what you might think for most PTAC condos. But @eva_needs_heat lives there , so I believe her.
    Edward F Young. Retired HVAC ContractorSpecialized in Residential Oil Burner and Hydronics
    IllinoisfarmerGGross
  • mattmia2
    mattmia2 Member Posts: 9,405
    Is it a ptac with a hot water coil or a univent with a self contained ac. Kind of 2 ways to look at it
  • eva_needs_heat
    eva_needs_heat Member Posts: 6
    @EdTheHeaterMan Thanks so much for the detailed illustrations. I also like your suggestion of using a credit card, very smart. I hope what I post below can provide more clues as to what may be wrong.

    Here are some photos of the unit and boiler ( @pecmsg yes it's my own combo water heater and boiler).

    I can confirm the circulator pump on the boiler is in fact working.





    Just a reminder, I have two PTAC units in my condo.

    For the unit my bedroom--the heat works! It only took moments for the coil to get hot and blow warm air. So I hope this can rule out any issues with the boiler entirely.

    As for the unit in the living room, I decided to give it another good bleed today (about three hours). Still saw bubbles through the entire time.



    @EdTheHeaterMan in the photo below I circled in yellow for you to see which valve I shut off when bleeding the unit (there are two). The second photo is of the new zone valve that was installed.




    In this photo, I marked in red which part of the coil gets hot and which part stays warm/cool.



    In this photo, I marked which pipe gets very hot and the other barely warm.



    Based on all this information, what are the chances that the issue is with the coil? Why isn't it heating through?




  • mattmia2
    mattmia2 Member Posts: 9,405
    There is air trapped in the coil. The only way to get the air out the way it is plumbed is to purge it. That section you highlighted in blue is a high point that will trap air without a way for it to get out. Close the other zone, open that zone manually using the knob on the zone valve.

    Turn the boiler off while you are purging.

    Now you will need to figure out the boiler piping. There needs to be a valve at boiler that can close off between the supply and return and allow the fill valve to supply water on one side of that valve and a drain on the other side of that valve to let the water from the fill valve be forced around the loop and out the drain valve.

    Show us some further back pictures of the boiler.

    This should take at most a couple minutes to purge the loop.
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 7,518
    I believe that you have an air problem. but you can't purge the way it is set up.


    Edward F Young. Retired HVAC ContractorSpecialized in Residential Oil Burner and Hydronics
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 7,518

    Edward F Young. Retired HVAC ContractorSpecialized in Residential Oil Burner and Hydronics
  • pecmsg
    pecmsg Member Posts: 4,680

    pecmsg said:

    You do not have a PTAC you have a Air Handler. The building supplies hot water or cold water depending on the time of the year.


    Look at this @pecmsg
    You might change your mind.
    https://islandaire.com/ptac/product/ez5r/
    Also @eva_needs_heat has her own boiler in her unit. Not exactly what you might think for most PTAC condos. But @eva_needs_heat lives there , so I believe her.
    We still call those Air handlers or windowsill units!

    PTAC Packaged Terminal Air Conditioner
  • eva_needs_heat
    eva_needs_heat Member Posts: 6
    @EdTheHeaterMan is there a way to fix the direction of this pipe? If I reached out to a plumber, how would I phrase what I need in order for the job to end with the heat working?

    @mattmia2 my thinking is that I shouldn’t have to do anything with the boiler given that the heat in the bedroom unit is producing heat, would you agree?
  • eva_needs_heat
    eva_needs_heat Member Posts: 6
    One thing I did notice this morning: the Air Release Valve on my boiler looks like it’s covered in calcium buildup in comparison to my neighbors’ that looks nice and new. Could replacing it be a potential fix for getting all the air out?



  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 7,518
    edited October 2023
    BINGO! that is where you let the air out. loosen the silver cap and see to you get an air hissing sound. You may even tap on it lightly with a wooden spoon. We call that a Percussion Adjustment. It's a technical term!
    Edward F Young. Retired HVAC ContractorSpecialized in Residential Oil Burner and Hydronics
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 7,518
    edited October 2023


    @EdTheHeaterMan is there a way to fix the direction of this pipe? If I reached out to a plumber, how would I phrase what I need in order for the job to end with the heat working?

    @mattmia2 my thinking is that I shouldn’t have to do anything with the boiler given that the heat in the bedroom unit is producing heat, would you agree?

    I would think the company that replaced that PTAC should have completed it correctly the first time. Was that the one that was recently replaced? If you do not get any satisfaction from the company that recently did the service call, and you end up paying again, ask the plumber to come and fix the heater. Once he arrives you can ask him if that air vent is in the correct location? Isn't that supposed to be on the top and not on the bottom of that pipe?

    And pay with a credit card. Tell the plumber that you want HEAT to come out of the heater. He is the expert. he should be able to make it work. You are paying for it to work. Not for them to guess, then get paid and it does not work tomorrow when they are gone.

    What is the status of the previous service company?
    Edward F Young. Retired HVAC ContractorSpecialized in Residential Oil Burner and Hydronics
  • mattmia2
    mattmia2 Member Posts: 9,405


    @mattmia2 my thinking is that I shouldn’t have to do anything with the boiler given that the heat in the bedroom unit is producing heat, would you agree?

    Because of the way that pipe is arranged, the only way to get the air out if it is to purge water through it from the boiler, you have to flow water through it fast enough that it carries the air with it and out a drain at the boiler since there is no bleeder at the high spot.
  • eva_needs_heat
    eva_needs_heat Member Posts: 6
    BINGO! that is where you let the air out. loosen the silver cap and see to you get an air hissing sound. You may even tap on it lightly with a wooden spoon. We call that a Percussion Adjustment. It's a technical term!
    @EdTheHeaterMan I kept turning the cap until it completely came off, no hissing sounds at all
  • mattmia2
    mattmia2 Member Posts: 9,405
    Was it already loose? it should be loose. it is crusty because it is leaking some water and should be replaced but you could just screw the cap down and forget about it for a while after you get the air out.
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 7,518
    edited October 2023
    EDIT

    OK then that is not the place where you get all the air out. Read the post I made just after that one.

    I still believe you already paid for this to be correct. You just need to be persistent with the last person you paid because what they did, failed to produce heat. My company would honor a warranty on that service call. The company I sold my business to would NOT honor any warranty in your case.

    It all depends on how you ask. I would start out with "Does your service or repair work come with a warranty?" They should answer yes
    "So if you do something to fix my heater and I pay you, then it still doesn't heat, how does the warranty work?" That depends might be a response

    "So if you charge me for a repair that does not solve the problem, do I get my money back or can you apply THAT money for the failed repair, to the repair that actually fixes the problem?"

    EDIT
    See if that gets you any satisfaction. The CSR who answers the phone may not have the answer to that, OR they may agree to your request for warranty service. SO GET THE NAME OF THAT PERSON. But If the CSR is smart, they will not have an answer and say that they need to check with the service manager.
    Then say "OK I'll hold while you get that answer."

    Once you get your answer, then decide if you want to continue with that company. If they say that is a fair way to look at the warranty (or something like that) then tell them to schedule the visit. Once they get the heat to work, then ask them if the previous service visit of $XX.00 that failed to get the heat to work is covered by that warranty that the service manager (Fill in Name) said you have. See if you get that fixed for a lower cost or even for free.

    Use the credit card for payment and dispute the charges if you are not satisfied.

    Edward F Young. Retired HVAC ContractorSpecialized in Residential Oil Burner and Hydronics
    mattmia2
  • JUGHNE
    JUGHNE Member Posts: 11,021
    Your thermostat, either on the wall or in the unit, must send power to the Taco zone valve for it to open and heat.

    Did you try the manual operation for it. Push and turn the knob to open that valve.
    If it stays closed then no water flow......"Push and turn for manual override".