I had a new ac built to order that replaced my old one 3 years ago. Right after warranty was off (2 years in) a/c started to act wierd. During winters from time to time, it starts to blow cold air and with no reason goes back to normal. During summer, all is ok though. This year again same thing happened. I manually overrided actuator to open position few times. After sometime spring inside it broke, so i bought new unit (erie ag13b020) and replaced whole head, hoping that problem will disappear. After 24h however, problem came back. During the day a/c blows hot air, stops automatically and starts right back working all good, but at night though set unchanged to 80 degrees, will start blowing cold air continiously. Only way to get hot air, is again manually opening water walve, which again will make it work great during the day, but fails at night though untouched. What seems to be the problem? Also what's that part on the pripe near erie looking like oversize "watch" battery seen on last picture? Can it be responsible for the on and off cold air? Thermostat itself seems to be work ok.
residencial HVAC (water based) cold air issues
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Could the temperature sensor (round thing) be the problem? Should it be connected with one of the cables, with the actuator (erie ag13b020)? i think now it's connected only with the thermostat. Also, on which pipe should it be placed on? In front of actuator on pipe that it sits on (opening valve is on), or other pipe, or behind?
thanks again
I have a feeling the temperature sensor might be the issue. I found old picture on the net showing how to attach sensor, and it shows attaching it to the motor of actuator first and later blower. Mine seems to be attach straight to blower but I don't know. My actuator looks different though as- it's push on valve ERIE AG13B020 NORMALLY CLOSED ACTUATOR, ON/OFF, 120V. pictures of mine above
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it seems to be ok. also it was working ok for over 2 years, and started acting crazy last winter and again now
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White to Blue closes below 60, White to Black closes above 88.
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This is a typical fan coil unit. (ours usually don't use that relay though, they just work with a thermostat designed to work without relay.)
Make sure the auto changeover switch is on the supply side, as close as possible to the riser wall as possible.
Does it continue to work as expected after forcing the valve open? As in, the valve is energised and stays open for some time after? Do you keep the fan always on, or set to auto?
The auto changeover does die, and I keep them in regular stock. Those thermostats fail much less often as the actuators and auto changeover switches.
Be careful though, everything will be 120v, including that stat. (it is not a regular thermostat.)
Cheers!
Make sure the auto changeover switch is on the supply side, as close as possible to the riser wall as possible.
Does it continue to work as expected after forcing the valve open? As in, the valve is energised and stays open for some time after? Do you keep the fan always on, or set to auto?
The auto changeover does die, and I keep them in regular stock. Those thermostats fail much less often as the actuators and auto changeover switches.
Be careful though, everything will be 120v, including that stat. (it is not a regular thermostat.)
Cheers!
The funny part about this unit is, that during rest of the year it works great. Only during winters, seems to fail, and that also occasionally.
When I force the valve open, it stays open and even thermostat is working (means will switch itself on and off automatically after reaching certain temperature). After some time level is released and also works with thermostat opening and closing valve. More frequent however, especially during the nights, the level in actuator won't move back and forth, will stay in closed positing and again have to be manually forced into open. I even changed actuator recently to new one, and same problem occurs again.
The thermostat I have, has temperature and 3 speeds. I just set it on and it runs switching heat on and off.
I am bit confused about the location of the changeover switch. I am attaching picture of how it was installed. It sits on the opposite pipe of actuator (both pipes deliver water though, I am not sure which one is main), in the middle. I ordered new switch and will try to install it. Where do you think I should move it? Do I need to connect the switch to actuator as I found in online instructon? (there's picture in my earlier post of it, mine switch is attached to blower though not actuator's engine). Thank YOU!
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Leave the switch the way it's connected. It should be on the pipe that's hottest in winter when the valve is open and the fan on. (In your case, you'll have to put panel back on for a min or 2 before checking since the fan is above the coil.)
Looking closer at the picture, that looks like an older fixed valve. Meaning that was valve cartridge might not be changeable. We always change the cartridge if it is changeable when replacing the actuator. (typically one will make the other fail) If you haven't changed it, then the cartridge is getting stuck. Very common, and very intermittent at the beginning. The problem is that, that valve body is soldered, so it's a bit of a pain to change. We would change it to unions/flares
Cheers!
Looking closer at the picture, that looks like an older fixed valve. Meaning that was valve cartridge might not be changeable. We always change the cartridge if it is changeable when replacing the actuator. (typically one will make the other fail) If you haven't changed it, then the cartridge is getting stuck. Very common, and very intermittent at the beginning. The problem is that, that valve body is soldered, so it's a bit of a pain to change. We would change it to unions/flares
Cheers!
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Supply if it's an auto changeover only on a 2 pipe, heat/cool building system. Return if it's a heating only system, and used to prevent cool drafts. This one looks like its an auto changeover on a heat/cool.
(I've had problems with it on the return on heat/cool loops, when the flow is somewhat poor. I prefer a 3 way valve with a bypass when using those though. It works much better)
Cheers!
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It is an auto change over stat.
Thanks. I really appreciate your time and advice. Here's the picture of valve on which sits actuator, do you think that it's changeable? It looks fixed to me. Is there any way manually I can check the valve? Thanks again
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