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5

Did you put fresh batteries in the Nest? No. Because the Nest doesn't take batteries :) So that raises a question. How does Nest power itself? It has a lithium battery (like a phone) but that has to be replenished somehow. The answer is, Nest depends on the fact that thermostat wiring is in series with the furnace relay. Power flows -----R ...


4

I had the exact same problem. I used a 3.5" x 10" rectangular duct to go up through the cabinet into the attic. In the attic, I used a rectangular to 6" round adapter, then 2 adjustable elbows to get the right offset and angle to line up with the roof vent, and a straight pipe from the elbows to go up through the roof. Bonus... I still have ...


4

I would find a boot that covers the cabinet opening and install that, then see where you stand. A bit of flex duct may be a good solution (the semi-rigid kind, not the cheap foil junk), but a side-offset boot may line up perfectly. This one looks like what I have in mind, though the offset may be an illusion: Image courtesy of Home Depot Be aware that such ...


3

The "round sensor in the ceiling" is part of a fire alarm and/or ignition/fuel cutoff circuit for the furnace and is EXACTLY where it's supposed to be. It's a "heat detector" (smoke insensitive, not prone to false triggering) and when things get too hot, it may (depending on what it's connected to) set off an alarm, cut off the fuel ...


3

For an A/C unit to reduce the % of relative humidity in your home a properly sized A/C unit coupled with a dehumidifier must run a long time to decrease that humidity. When the A/C unit is first turned on, it begins to cool the room temperature which may actually increase the relative humidity. Just because the room temperature is reduced does not mean that ...


2

To me, the biggest issue here is that, while "the condensation would be only on the inside of the pipe", you are in fact anticipating condensation, which can lead to mold, in the pipe. And if you're blowing air through the pipe, you could be creating a mold nursery in the pipe that significantly increases the amount of mold spores in the air, and ...


2

I can't speak to this specific unit, but in general forced air HVAC systems have two modes for fan: Auto = Fan runs whenever the heat or air conditioning is running - i.e., to circulate the hot or cold air On = Fan runs all the time. Most often I see "Auto". Occasionally people prefer "On", especially in the current pandemic as ...


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Look at the bottom of the tag where it shows the amp rating of the contactor. Get a new one rated the same size or slightly larger with the same number of switched contacts and a 24 volt coil.


2

I searched R8243 and came up with a Honeywell cross R4243b1012. Part numbers change all the time but this should be a compatible part 24v coil and a double pole contact set without knowing your compressor size it would be hard to guess at the right size because Honeywell did not provide the specs for the original. It’s not a big deal as long as the control ...


2

if the nest is not detecting the W wire you have really three likely options Something is wrong with the wire. Something is wrong at the furnace Something is wrong with the nest, which does happen. If the old thermostat works then I would imagine that the controller units/boards etc in the furnace itself are PROBABLY ok, not a certainty but probably. I ...


2

You should be able to wire a thermostat to R, G, and C on the fan control relay and have it control the fan According to the wiring diagram on your furnace, the fan relay selects between AUTO operation (where the blower thermostat in the plenum controls the fan) and always-on operation, so you should have no issues wiring your new thermostat to the R, G, and ...


2

Well, I know this post is old but a simple way to test your pressure switch is to turn off your furnace first and close the gas valve for safety, then gently unhook the air tubing from your draft inducer and gently suck on it using just the suction your mouth creates, I wouldn't inhale it, you should hear the pressure switch click and feel a restriction ...


1

"Suction" is not desirable. The main problem there is likely inadequate slope on the line coming straight out from the air handler, and/or inadequate slope on the leg to the air gap. The line across the top front appears to have adequate slope. The actual trap is beyond the air gap, in larger diameter pipe. In my biased opinion, the second major ...


1

As isherwood mentioned in a comment, that round pipe is the flue. It's what takes the hot, toxic, exhaust gasses from the burned fuel and gets them out of your house so you don't asphyxiate and die. You can insulate the flue with an appropriate high temperature insulation and ensure that all the heat left in the flue gasses is piped directly out of your ...


1

It is possible that adding a C wire would fix it. From Nest support: In some cases, you may experience problems after installing your Nest thermostat that can be fixed by connecting a C wire, or by removing the wire from the C connector. Heating or cooling is always on, and won’t turn off This is just because without a C wire, the nest drains a little ...


1

The biggest reason is probably "because that's where it fits." It's true that warmer air can carry more grains of water than colder air can. That's a good physics-based reason for locating the humidifier on the supply air duct. But lots of homes have an air conditioning evaporator sitting atop the furnace. Furnaces don't often get installed in a ...


1

I can't quite tell whether you're seeing normal operation and mistaking it as a problem or if there's actually a problem. The white crumbly stuff is scale, also called mineral deposits. It is calcium and other minerals that are dissolved in drinking water. I've drawn a line on the photo below to illustrate the path water should travel. It flows from the ...


1

Your main trunk duct may be undersized for the return air on the main level. If this is a new system that used the existing ductwork the fan speeds may be set for the highest efficiency. In my opinion the system is not properly sized or set up correctly not enough info but one of the 2 is true. For a fix: It looks like a Rheem but not sure, the Rheem ...


1

I would call in an HVAC company that is versed in heat pump repair. Since we do not know what is wrong with the electric back up heat we can only guess. The problem may be as simple as a bad sequencing relay, broken or loose wire, or a bad heat strip. Instead of being cold, I would get it serviced.


1

The external surfaces of the furnace and ductwork are not hot enough to be a fire hazard with the items you listed. As we don’t know if this is a newer sealed combustion system or older gas vented system you would need to stay away from a vent they can be hot. I would not hang heavy items like gallons of anything even if magnets could hold them the duct’s ...


1

There are 3 things to confirm about your room: 1) excess heat gain from external or internal sources. 2) inadequate air flows (cfm) into and out of the room. 3) actual air and surface temperatures. An IR temperature sensing gun will locate any hot spots on wall, ceiling or floor. Do temperature checks before the room heats up fully, then do it hourly to find ...


1

With the info you have provided we really can’t help you, there are mini splits out there you can install for ~1500$ I would want see how your system is set up because your hvac guy sounds like he knows less than my neighbor and I helped him put in a mini split. Unless you can provide some specifics I vote to close.


1

You have a single start cap there not a dual (from the wires I can see) The resistor is a safety bleed down for the cap. I would ASSUME that the blower motor uses a run cap and if you look on the upper right of the label on the blower motor it does give a run cap value of 5.5mfd. Bleed resistors are not normal on run caps. You may be able to find the ...


1

If the duct is blocked off at the end so that no air flows through then it should have minimal effect on the system. Removing it should not be expected to make any efficiency improvement. On the other hand, if that duct is just lost in the floor or ceiling somewhere and is discharging conditioned air into who-knows-where, then yes you might gain some ...


1

My parents' house has one place with vents that look exactly like that - the duct has two vents, one on each side, and there is a baffle inside such that you cannot look through the vent and see the other room. The baffle extends about 1-2 inches past the edge of the registers. I spent some time trying to find a pre-made part (or even a picture of someone ...


1

One of those transformer terminals is "R" the other is "C" If the red wire joins to the thermostat "R" wires then the beige wire is "C" Thermostat wires should not be inside that junction box with the mains wiring, get a new box for the thermostat wires.


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In my limited experience, most homes in the tropics are not particularly well air sealed. So, air moves from inside to outside easily, even with the doors and windows closed. As such, when your A/C is running, it may well be that you are getting a great deal of outside air inside, and a great deal of inside air is moving outside - so when you bring in ...


1

Another cause would be a loose stem package sealing right at the spindle of the dark valve handle - if there is a stem package sealing at all. Just close to that handle is a big nut which needs some tightening (only very few, e.g. 1/8 turn every 5 years) from time to time. Often, it can be sensed if it is too loose. If the valve or washer need to be ...


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As a temporary fix you can get a brass hose cap and screw it on the spigot:


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Is it the spigot, or is there leakage from a corroded boiler? If you determined it's the valve that's leaking, you'll need to: Shut the electricity to the heating system to prevent it running while dry. Shut the cold-water feed to the boiler. Drain the whole heating system through that valve... you could run a garden hose to the fitting once it's cooled. ...


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