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weird home hvac behavior

STEVE_17
STEVE_17 Member Posts: 42
Hi,

(I am a home owner not a professional so please excuse the non-technical term i use)

my heating system is a gas boiler with 3 pumps and a air handler per pump (hydronic?) i also have ac units outside 1 per air handler.

I just put the heat on for the first time since the AC was added and i noticed that the condensors outide are running when ever the air handler is on. i turned off the fuses for the condensors and called the person who installed it who told me that everything is OK and thats the right thing to do. Is he trying to avoid a visit?

i noticed i have a sensor on the water pipe outside the air handler that has 2 wires connected to the board inside the air handler - i guess thats how it knowes to come on when the radiator inside it is hot but the same 2 posts also have wires coming from the thermostat so im guessing that when the sensor sends the on signal it causes the condensor to confuse that for an on signal as well which turns them on...

what is the industry standard for solving this? control via fuses sounds fishy

Comments

  • lchmb
    lchmb Member Posts: 2,997
    if your

    Tstat is set for heat and the boiler and zone is running then you have a wiring issue. The condensor should not activate with the heating system calling. And controlling it by fuse is not the right way..It would be best for you to have someone stop in and check it...IMHO..:)
  • Alan_6
    Alan_6 Member Posts: 87


    > Hi,

    >

    > (I am a home owner not a professional so

    > please excuse the non-technical term i use)

    >

    > my

    > heating system is a gas boiler with 3 pumps and a

    > air handler per pump (hydronic?) i also have ac

    > units outside 1 per air handler.

    >

    > I just put

    > the heat on for the first time since the AC was

    > added and i noticed that the condensors outide

    > are running when ever the air handler is on. i

    > turned off the fuses for the condensors and

    > called the person who installed it who told me

    > that everything is OK and thats the right thing

    > to do. Is he trying to avoid a visit?

    >

    > i

    > noticed i have a sensor on the water pipe outside

    > the air handler that has 2 wires connected to the

    > board inside the air handler - i guess thats how

    > it knowes to come on when the radiator inside it

    > is hot but the same 2 posts also have wires

    > coming from the thermostat so im guessing that

    > when the sensor sends the on signal it causes the

    > condensor to confuse that for an on signal as

    > well which turns them on...

    >

    > what is the

    > industry standard for solving this? control via

    > fuses sounds fishy



    There is so many things it could be, wrong thermostats, mis wiring, etc...
  • Mark Hunt
    Mark Hunt Member Posts: 4,908
    Hmmmmmmmmmm


    sounds like a low voltage control wiring issue.


    Mark H

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  • STEVE_17
    STEVE_17 Member Posts: 42


    is this sensor on the water pipe into the radiator something that is generally used? i have never seen one before but it kind of makes sense- u dont want the air to turn on before the radiator is hot enough...

    also what are the w1 and w2 posts on the board in my airhandler (york) they are not being used
  • todd s
    todd s Member Posts: 212
    wiring issue

    The sensor on the pipe could either be an aquastat to turn on the fan after the pipes get hot or it could be a freeze sensor that will turn on the pump if the temp gets too low. I think you have some low voltage wires crossed however.
  • STEVE_17
    STEVE_17 Member Posts: 42


    ok i traced the wiring and here is a summary:

    aquastat (L6006C) to R and G on air handler(AH)
    tstat rc and G ALSO to R and G on air handler(AH)

    AH C and Tstat y to compressor.

    AH Y is connected to a yellow wire but as far as i can tell the other side is not connected to anything.

    this explains how the AH turns on - it gets fooled by the aquastat into turning on. it doesnt explain why the compressor turns on but it does....

    I can provide more info if needed.

    thanks!









  • scott75
    scott75 Member Posts: 100


    You have me very confused. Did you have the air handlers before you had the AC? You don't typicaly use a boiler in combo with an air handler for heating. If the air handler wasn't there before the boiler, it shouldn't, along with the outdoor units, come on at all during a call for heat by the thermostat. Did you get heat pumps or just AC added? You really should know more about your equipment as a homeowner. Did the installing contractor say to just keep the fuses off till spring or just till he can get back to look at the problem in a day or two? Either way, have him come back to show you how to work your equipment and what you can expect from it, sequence of operations, where your air filters are, ect... This will also benifit him by you not calling everytime you think something may be wrong when in fact you just don't understand how the equipment is supposed to work.
  • STEVE_17
    STEVE_17 Member Posts: 42


    i understand more about my heating system then 80% of non pro homeowners out there. that should be obvious from the detailed description of the problem. Please dont rush and blame this on user error.

    the boiler and air handlers went in first with the intention of adding AC later. AC was added about 8 months later by another technician - the son in law of the original technician who retired. the son in law moved the business to suffolk and will only come out to fix a problem which he says i dont have. i am trying to figure out the control for myself and to sound like i know what im talking about next time i call
  • scott75
    scott75 Member Posts: 100


    I didn't say this was user error. It doesn't sound like it. Don't put words in my mouth. But you didn't accurately describe how your equipment works. So...model #'s off boiler, air handlers, do you have an aquacoil?...And frankly, based on your original post, you don't sound like you know more about your HVAC equipment than 80% of non-pro homeowners. Maybe you didn't convey yourself well, maybe I'm tired and not thinking right. Only trying to help.
  • Ted_9
    Ted_9 Member Posts: 1,718


    > i understand more about my heating system then

    > 80% of non pro homeowners out there. that should

    > be obvious from the detailed description of the

    > problem. Please dont rush and blame this on user

    > error.

    >

    > the boiler and air handlers went in

    > first with the intention of adding AC later. AC

    > was added about 8 months later by another

    > technician - the son in law of the original

    > technician who retired. the son in law moved the

    > business to suffolk and will only come out to fix

    > a problem which he says i dont have. i am trying

    > to figure out the control for myself and to sound

    > like i know what im talking about next time i

    > call



    < A HREF="http://www.patriot-hvac.com/">PATRIOT HEATING & COOLING, INC.
  • Ted_9
    Ted_9 Member Posts: 1,718


    > You have me very confused. Did you have the air

    > handlers before you had the AC? You don't

    > typicaly use a boiler in combo with an air

    > handler for heating. If the air handler wasn't

    > there before the boiler, it shouldn't, along with

    > the outdoor units, come on at all during a call

    > for heat by the thermostat. Did you get heat

    > pumps or just AC added? You really should know

    > more about your equipment as a homeowner.

    Scott , You are way off talking to this home owner like that. It actually sounds like he know quite a bit more than an average H.O. and that his contractor is not qualified to install HYDRO-AIR systems and avoiding this home owner..

    PATRIOT HEATING & COOLING, INC.
  • bob_25
    bob_25 Member Posts: 97
    Steve

    you don't say what kind of stats you have. If you have Q539 honeywell or similar when the fan switch on the sub-base is in the auto position G is jumped to Y. When the aquastat tells the fan to start in the heat mode it jumps R to G and therefore to Y and AC starts. Try setting the fan switch on the stat to on. The fan will run continiously but the AC shouldn't come on. That will tell you if this is the problem and we can go from there. bob
  • STEVE_17
    STEVE_17 Member Posts: 42


    Bob,

    thanks for explaining that - sounds like thats whats going on.

    the aquastat i have is a honeywell L6006C. I tried putting the Tstat in fan mode and the condensor did not come on! im at a loss though to what that means or where the problem in wiring lies.

    thanks again


  • bob_25
    bob_25 Member Posts: 97
    Steve

    what brand and model no. thermostats and sub-bases do you have. bob
  • STEVE_17
    STEVE_17 Member Posts: 42


    Bob,

    the Tstats are all Robertshaw 9600's http://www.icca.invensys.com/robertshaw/9600.htm

    if by "sub-base" you refer to what i call air handelr they are not marked with any brand (the condensors are by york) but the warrenty card went to "unitary products group" and the model number is fr2p.

    thanks

  • scott75
    scott75 Member Posts: 100


    Where exactly was I "way off?"
  • bob_25
    bob_25 Member Posts: 97


  • Paul Bock_2
    Paul Bock_2 Member Posts: 40
    T-stat sub base

    The sub-base is the mounting plate that the thermostat attaches to on the wall.


    There are many differant styles and configurations.

    The problem you have is being caused by The aqua-stat.

    On your wall thermostat "y" is internally jumpered to "G" so that the fan starts on a call for cooling if the fan switch is in the "auto" position.

    On your air handler the aqua-stat has been added to bring on the fan with a call for heat, and when the contacts make it sends power to the fan relay, but it also sends power back to the sub-base on the "g" wire, and causes a "backfeed" to "y", due to the fact that they are internally jumpered.

    You should be able to correct this, either with a differant sub-base or with a differant model of t-stat, one that would start the fan on a call for heat without the use of the aquastat.

    PaulB.
  • bob_25
    bob_25 Member Posts: 97
    Steve

    the sub-base is built into your themostat. I drew a schematic based on the wiring info you have posted and what was at robert shaw and I don't have enough info to give you a definite solution.
    You have these new fangled space age solid state thermostats and manufacturers don't give internal schematics anymore.
    Your problem is solvable. You need a good tech. If you post how many wires are coming off the thermostat and where they are going and how many transformers you have and where they are located(there may be some in the condensing units) Iwill try to help. bob
  • jerry scharf_2
    jerry scharf_2 Member Posts: 414
    Could it be your Attitude?

    > Where exactly was I "way off?"




    Bob asked a series of fine questions to get at the details of the situation. PaulB gave a simple test to see if his guess of the wiring problem was right. Steve was right in there and has the solution to his problem.

    What did you contribute to this thread? You questioned Steve's knowledge as a homeowner and doubted his description of the system and the problem. No useful information was provided and you got an understandably defensive response from Steve. I see no help whatsoever to this person who is trying to sort out a problem not of his own making.

    Does that help you understand where you were way off? Reading this thread (minus your comment) is a great example of how the wall can bring people together to help out someone in need.

    jerry
  • sh
    sh Member Posts: 2


    Paul,

    that was my gut feeling once i saw the leads from the cooling posts on the tstat connected with the leades from the aquastat on the air handler... i was missing the info about Y & G shorted in auto mode...

    Bob,

    Thanks for you offer. I will try to draw something up and email you - im not sure i can post images on the forums.

    Thanks again

    Steve
  • David_5
    David_5 Member Posts: 250
    Wiring problem

    I see I'm late to this party but here goes anyway. Your system will need a separate fan relay to run the fan in the air handler on a call for heat. The original fan relay that came with the air handler will turn on the fan in cooling. Call the installer back to fix.

    David
  • Ken D.
    Ken D. Member Posts: 836
    Air Handler

    I tend to agree with David. The lack of a fan relay is most likely the problem. Although the t-stat is possible.
    One question though.The installing
    contractor said that it was supposed to work this way. Any chance the outdoor unit is a heat pump? The sensor could be used to turn off the outdoor unit when the water coil is hot. Just wondering.
  • Dave Bush
    Dave Bush Member Posts: 155


    Actually, a simple relay added to the unit to lock out "Y" during heating would solve the whole problem.

    Not hard to wire in, but the installer should have foreseen this problem...
  • jim lockard
    jim lockard Member Posts: 1,059
    Looks to

    Me to be at the the T-Stat may need a stat that has a seperate Rh and Rc connection but this just a 1st glance though.
  • John R. Hall
    John R. Hall Member Posts: 2,245
    As Dan would say...

    "That'll be $800 please."

    :-)
  • STEVE_17
    STEVE_17 Member Posts: 42


    I actually started looking for a tstat that will not short the Y in heat mode but its seems impossible toget that info from the websites. I'd rather not mess with relay since that is beyong my knowledge.

    im not counting on this installer anymore. a 2nd conversation with him resulted in "I always tell my clients to turn the fuses off in the winter more reliable then a relay - you dont want something to turn the ac on in the winter when its frozen with ice and snow" (sort of makes sense i guess).

  • Dave Bush
    Dave Bush Member Posts: 155
    Unplugging

    Can't hurt.

    But the fact of the matter remains, that there are thousands of hydro-air systems that have an isolation relay installed in them to make sure that YOU, the HO, don't forget to pull the disconnect, and wind up running your AC along with your heat, which can result in not only running your energy bills up, but possibly damaging the condensing unit of the ac...

    There are actual control systems available these days for built up hydro-air units.

    The seven or eight that I've installed, I've installed an isolation relay, that, when the heat calls, it energizes the relay coil, which open a set of contacts, through which the "Y" (Compressor contactor) wire from the tsat is broken.

    There is next to no load across these relay contacts at any given point during the year, and these relays are rated to handle 12 Amps at 120VAC. I have NEVER seen or heard of one of these relays failing in this application. Sure, it could happen, but what is more likely, is that the HO will forget to pull those fuses.

    The potential for damage is greater without the isolation of the compressor contactor, than with. As an HVAC professional, I'm certain that your installer would agree with this line of thinking, if he were to give some more thought to it.

    It's a simple wiring job, for an HVAC technician. It's also cheap insurance.
  • Dave_41
    Dave_41 Member Posts: 14
    T-stats

    There are some t-stats out there that will not give you the problem, or you could use a heat pump type and utilise the B and O terminals to prevent the problem. We have had problems with these types of stats and the wiring gets complicated. The isolation relays are much cheaper and more reliable but we have seen many instalations over the years where the installer either would not or could not take the time to install the relays and many customers have told me "they just told me to turn off the circuit breakers in the winter". Yes, this will work but this is not something the average home owner will remember to do until he notices the condensing units running and by that time it may be too late for the unit. Also in the spring and fall where you may need heat at night and a/c during the day it is a real pain. One other problem with turning the condensing units off is that although the unit will not run, the operating contactor in the outdoor unit will be pulled in anyway on a call for heat. Not really detrimental to the contactor but it creates a small warm area in the control box that attracts insects and rodents in the late fall. We have found many contactors so plugged up with these that they fail on first usage in the spring!
    Get someone to install the isolation relays and you should not have to worry about the system again.

    Dave
  • Dan Foley
    Dan Foley Member Posts: 1,260
    Taco relay

    Take a look at the Taco HAFC-01 fan coil relay. It will isolate the thermostat from the air handler and condenser. It would solve the problem you describe as well as simplify the wiring. We use these on just about all of our hydro-air jobs. -DF

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  • STEVE_17
    STEVE_17 Member Posts: 42


    I'd like to thanks everyone on the board again for your help!
  • Dunwell
    Dunwell Member Posts: 20
    Munchkin full setup New Construction advice

    Hi all,

    New construction in the Berkshires (NY/MA) area. Made contact with a very open and cooperative plumber who will work on time basis only. I'm homeowner, supplying all materials. He makes helpful suggestions and we work to keep within budget.

    He did heat loss calcs (78k) and I'm about to make a purchase of boiler, water heater, pool heater. House will be well-insulated, radiant heating throughout (slab in basement, lightweight concrete on upper floors), with two adults only.

    Please let me know what you think of this setup before I order:

    *Munchkin T-80 (or 140 if suggested)

    *SuperStor Ultra (SSU30) water heater

    *Jass LT water to water heat exchanger OR SuperStor Pool heater (this is for an indoor lap pool, 7k gals. in a room insulated with Icynene). I'm leaning towards the Jass because of it's nice price ($300) and compact size.

    I don't want to oversize the boiler, that's why I'm considering the 80M Munchkin over the 140M.

    Want to keep this as simple as possible, but want the best efficiency (of course). What are the best controls to get? Would like outdoor reset and I definitely want hot water FAST.

    Thanks for your advice!
    Dun
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