All condensate drains go into a trap. The condensate trap is absolutely mandatory for a high-efficiency gas furnace. Since the drain taps into the exhaust system, leaving it open to the air would allow for a potential exhaust/flue gas leak in the living space, which is a big no-no.
Do you need a condensate trap for a high-efficiency furnace?
All condensate drains are collected in a trap. For a high-efficiency gas furnace, condensate traps are required. The drain connects to the exhaust system. Leaving it exposed to the air could result in an exhaust gas leak in the living area. Furthermore, if the inducer motor weren’t caught, it would suck air through the drain.
Do you need a condensate drain on a gas furnace?
All condensate drains go into a trap. The condensate trap is absolutely mandatory for a high-efficiency gas furnace. Since the drain taps into the exhaust system, leaving it open to the air would allow for a potential exhaust/flue gas leak in the living space, which is a big no-no.
Do I need a trap in the condensate drain line?
Most manufacturers specify a trap in the condensate drain line as part of their installation instructions. Some systems do not need one, based on their design, and several mini-split manufacturers require that one NOT be installed.
Can You double trap a gas furnace drain?
Double trapping anything will cause the drain to not work. High efficiency gas furnaces all have an internal trap. Highlight that information in the install manual and rub the manual on the nose of the inspector. If YOU want change, YOU have to first change.
Does a furnace condensate drain need a trap?
All condensate drains go into a trap. The condensate trap is absolutely mandatory for a high-efficiency gas furnace. Since the drain taps into the exhaust system, leaving it open to the air would allow for a potential exhaust/flue gas leak in the living space, which is a big no-no.
Why does a condensate drain need a trap?
Condensate drains typically have traps, which are designed to keep air from moving in or out of the air handler without preventing condensate drainage. The absence of a properly working p-trap could push unfiltered air into your home and cause an overflow of the condensate drain.
Should AC drain line have trap?
First, the coil that your primary drain line is running off of needs to be at a downward angle to allow the water from the coil to drip into the drain line. Every drain line also needs to have what is called a “P-Trap”.
Where should furnace condensate drain?
The condensate drains out through a pipe, usually on the bottom of the furnace. Most high-efficiency furnaces also have a secondary drain line that comes out of the flue pipe. This secondary line is used to drain any residual moisture so it doesn't leak into your furnace.
How deep should the condensate drain trap be?
If a unit were to be operating at minus 6 inches WC maximum negative plenum pressure then the trap height, per the guidelines shown in Figure 1a, requires 7 + 3½ + 1½ + 1 inches of height from under the floor or about 13 inches below the floor level.
Should condensate trap be full of water?
The boiler should never be operated without the condensate trap in place, as it prevents noxious combustion gases from travelling down the condensate pipe. Should the trap have to be removed from the boiler, it must be topped up with water when it's replaced.
Can the furnace drain and the air conditioning drain be run with a common drain?
In general, you should not run the air conditioning condensate drain and the furnace condensate drain into a common line. The positive pressure from the coil can travel through the drain to the furnace drain and cause the vent safety switch to trip.
When should you use a running trap?
P trap and running trap are commonly used as condensate drain traps for HVAC. The running trap is recommended for air conditioner drains. However, it is widely criticized because of its shallow bend, which may not be enough to withstand negative pressure during normal operation.
Can you drain furnace condensate outside?
A furnace produces condensate as it works (it's part of the combustion process), and this condensate must be drained and removed to the outside. If the pipe that runs the condensate to the outside of the house freezes over, your furnace won't be able to work!
How much water does a furnace drain?
A 90% or higher efficiency furnace produces around 0.8 gallons of condensate per hour of running. This equates to about five or six gallons per day of acidic water from condensation each day. Most of the time, the drain and drain line runs to outside the home and the condensate just seeps into the ground, harmlessly.
Why do high efficiency furnaces drain water?
When a high efficiency furnace releases the exhaust gases, condensation is created. This condensation is a significant amount of moisture on the PVC pipe, and it needs to be drained either into a floor drain or a condensation pump. A water leakage occurs when the condensation is unable to drain properly.
What is a condensate running trap?
The trap is a depressed U-shape portion at the condensate pipe. It is purposely shaped to perform its functions. Due to its shape, the water automatically creates an air seal to prevent sewer gases from entering through the outlet pipe while at the same time stopping the vapors from escaping through the inlet pipe.
What does EZ Trap do?
An EZ Trap is a U-shaped device that allows you to periodically clear the drain line of your system and prevent backups and overflows from happening. The EZ Trap also includes a low-voltage float that, if water rises above a certain level in your system, will trigger a shut-off until the line can be repaired.
What happens if you double trap a drain?
Anytime your drain goes up and down more than once, you have a double trap UNLESS you place an air vent between the two traps that vents ABOVE the drain inlet. The double trap causes drainage issues because air becomes trapped between the two traps, and air is lighter than water.
What are the defects in a condensate drain line?
The photos below illustrate two recurring defects we see with condensate drain lines: termination at or very near the wall of a home, resulting in a moisture problem at the wall, and terminations that blocked by dirt or mulch and will clog easily.
Why is the drain piping open?
Because the drain piping is open at one end to the interior of the air handler that is blowing air into the supply vents around the home, and at the other end to the outside, it will also blow conditioned air out the pipe to the exterior. Actually, depending on where the opening to the drain is located in the flow of air through the air handler, ...
Do I need a trap in a condensate drain?
Most manufacturers specify a trap in the condensate drain line as part of their installation instructions. Some systems do not need one, based on their design, and several mini-split manufacturers require that one NOT be installed.
How deep should a drain pipe go into a condensate pump?
You could try putting a bucket there to see what happens. The drain pipe should be above the water level. The drain pipe should only be into the pump about 1/8 ".
What is the black hose vent on a trap?
The thin black hose vents the trap and is probably a critical sized opening inside the port at the trap and the ventor fan. Siphoning is very tricky and it does not take much to slow it down. May have to take a paper clip or small bit and ream out the port on the ventor fan, can get a sulphur buildup there.
Why does my furnace hose fill up with condensate?
It is easy to see because the hose is a clear material. After the furnace runs for a while the hose will fill up with condensate, even though it is higher than the trap. It acts like there is some kind of airlock on the line preventing it from draining.
How to get rid of a horz trap?
Cut the trap out and soak the whole thing in a bucket of strong bleach/Javex for an hour and then flush it. I would cut the horz pipe after the trap, then go to HDepot and get some large clear hose to cobble it back together.
What can go wrong with a P trap?
If Im not mistaken isnt that plug with the red clamp supposed to be open so the trap can vent properly.The only thing that can go wrong with a p trap is not installed correctly with the vent and or it getting plugged up .I think your not letting it vent properly after the trap does its job.It fills up than it cant drain into the sump.
Does a furnace have a concentric vent?
The furnace has a concentric vent setup for combustion air/flue exhaust. Everything appears OK with that - no external blockage and the exhaust seems to be exiting properly with decent velocity.
How many drains does a furnace have?
Most furnaces will have at least two internal drains, typically one for the heat exchanger and one for the vent, usually at the inducer outlet or on the inducer housing. The secondary heat exchanger outlet is sealed inside a plastic part called the collector box, designed to collect the condensate and drain it.
How do I clean a drain trap?
The only downside to the trap is the potential for blockage. The trap needs to be cleaned out regularly, and that should be done during every maintenance. Rinse it out, and make sure water flows through the trap properly from all its ports. If there’s any poor flow, fill it up and blow through it a few times to get the dirt out. Hotter water helps with stubborn blockages. The need for regular cleaning also means that drains should be installed as much as possible in a way that allows for the trap to be easily removed. I highly recommend using clamped flexible hoses for the drain, used as close to the trap as possible. Avoid hard-piping the whole drain, as it will be impossible to remove and clean out the trap.
How does a high efficiency furnace work?
High efficiency (or 90%, or condensing) furnaces use a set of two heat exchangers to retrieve more heat from the combustion products than their mid-efficiency counterparts. Because of this, they generate flue gases much colder than those of a mid-efficiency or natural draft unit. That not only completely changes the way the furnace has to be vented (I will talk about venting specifically in a later tip), but a lot of condensate is also generated, which we'll focus on. This water comes from two sources: moisture, which was already present in the combustion air, and the combustion process itself, as the hydrogen atoms from the natural gas molecules (methane, CH4) combine with oxygen to form water. Now, as technicians, you don’t need to know this part, but if you’re a bit into chemistry, here’s the basic chemical equation:
Can you run a furnace drain in an area that freezes?
Avoid running the drain in an area where it could freeze. That includes running it under the natural fresh air inlet if there is one. Finally, note that furnace condensate is acidic, and some states/provinces/countries may require the condensate to be neutralized prior to draining. —Ben. Share this:
Do condensate drains go into traps?
All condensate drains go into a trap. The condensate trap is absolutely mandatory for a high-efficiency gas furnace. Since the drain taps into the exhaust system, leaving it open to the air would allow for a potential exhaust/flue gas leak in the living space, which is a big no-no. Additionally, the inducer motor would suck air through ...
Why do air conditioners have P traps?
A P-Trap serves a very important purpose on an A/C unit. See, when moist air hits something cold, the water condenses out of the air and collects on the cold surface. Air Conditioning units pull A LOT of water out of the air. That is why in the summer, your car drips water. All air conditioners have a special drain for this condensation.
What is the purpose of a P trap?
The same thing applies to our air conditioner, but in our case, the purpose of the P-Trap is to prevent outside air from being drawn through the A/C unit. The weight of the water in the trap is enough to prevent this, while still allowing condensation to flow freely. Another key component of a P-Trap is an air vent….
How high should a P trap be?
That the exit point of the trap is 4 to 6 inches lower than the entrance point. The overall height of the trap should be 8 to 12 inches, and the distance between the two sides of the trap should be 4 to 6 inches.
What is a P trap?
What is a P-Trap. A P-Trap is NOTHING more than a properly shaped piece of pipe…. No moving parts, just the proper shape so gravity does the work for us. See below for an image of a sink P-Trap (which works the same way). See, water won’t flow up-hill….
Does an air conditioner have a drain?
All air conditioners have a special drain for this condensation. Some A/C units (like ours) have a negative air pressure inside them when running. What this means, is that the air is being sucked through the air conditioner instead of blown through, and so the inside of the air conditioner is at a lower pressure than the outside air.
How does an air conditioner drain?
One primary function of the air conditioning system is to dehumidify the air by removing water as it passes through the air handler . Collected in a drain pan below the cooling coil, as illustrated in Figure 1, the water must be removed to prevent damage and contamination to the air handler system and building. Draining water from a condensate drain pan is not a simple process. The blower that forces air through the system creates a pressure in the drain pan compartment, which adversely affects condensate removal. When the blower is located downstream of the cooling coil, the pan pressure is negative (below ambient) and when located upstream of the cooling coil, the pan pressure is positive (above ambient). These systems, referred to as draw-through and blow-through systems, respectively, require special provisions to allow condensate drainage. Failure to provide successful condensate drainage causes a multitude of health and property damage issues.
What are the design features of a condensate trap?
The drain system design features necessary for acceptable condensate trap performance include: geometry dimensions that match the drain pan pressure; provisions for priming and debris cleanout; means for preventing drain pan overflow (to protect against untimely flow blockage); and a method for preventing trap freeze-up in sub-freezing environments. Designs that illustrate these features are shown in Figures 7and 8, for draw-through and blow-through air handlers, respectively.
What is the function of positive pressure in blow through drains?
Without special provisions for draining, the positive pressure in blow-through drain systems aids the drainage of condensate, but the exhausting air entrains condensate and blows it onto floors, walls, and other components where it can cause damage and present health and safety problems.
How does a condensate drain pan affect condensate removal?
Draining water from a condensate drain pan is not a simple process. The blower that forces air through the system creates a pressure in the drain pan compartment , which adversely affects condensate removal. When the blower is located downstream of the cooling coil, the pan pressure is negative ...
What can affect the operation of a trap?
Seasonal variations, such as very dry or cold weather, may adversely affect trap operation and condensate removal.”. Two national mechanical and plumbing codes, International and Uniform, do nothing to prevent the failures described in the ASHRAE Standard.
Is a trap system the same as an industry standard?
Installation of the acceptable trap system is the same as installing the “industry standard” system if freeze-up and pan overflow protection are provided. Figures 9through 12illustrate installations in draw-through and blow-through air handlers. The trap heating device and the water level system are installed in accordance with the manufacturer’s installation instructions.
Is condensate drainage a standard?
Condensate drain systems accepted as the “industry standard” include water traps, like the one shown in Figure 2. Properly designed and maintained, trapped systems can provide successful condensate drainage. However, within the industry there is no definition of what constitutes proper or acceptable design.
Why do inspectors want furnaces double trapped?
Inspectors here are retards and want them trapped either way, they also want furnaces double trapped because they dont know their a$$ from a hole in the ground. Double trapping anything will cause the drain to not work. High efficiency gas furnaces all have an internal trap.
Why won't my mini split drain?
Lots of mini split systems won't drain if they have a trap in the condensate line.
What is the vertical offset of a straw trap?
The trap has a vertical offset that must be greater than the suction force of the unit. So, if your unit has 1" of negative suction, then the vertical offset must be greater than 1". That means, even with the air sucking the straw, it can't pull the water high enough to offset the drain-out end of the trap, and so the water will flow.
Can a mini split drain if there is a trap?
Lots of mini split systems won't drain if they have a trap in the condensate line.
Can condensate lines be drained into sewer lines?
from what I've read condensate lines should never be drained directly into sewer lines. If they can be installed there they must be installed upstream of a trap.
Do you need a P trap for a Trane A/H?
The new Trane a/h will not require p-traps. In our area you cannot tie the condensate line into the sewer system anyway.
Can a P trap affect a compressor?
it depends on the design of your unit. sometimes line without p trap can affect your motor compressor if your motor compressor installed above condensing unit.
Why don't I put a trap on the positive side?
It doesn't NEED one on the pos side. I don't put one on positive side because traps can sludge up and clog the drain.
Where is the P trap located?
Lastly the P-Trap shall be located close to the source of condensate, I have seen traps that are near the termination point on a long run, problem is that the condensate will build up momentum and siphon all the water out of the P-trap leaving it useless.
Do you need a P trap on a coil?
1. You don't need a p-trap on coils in the positive side. If you Instal one for code purposes, it needs to be vented on the coil side. The water in the p-trap will not allow plumbing odors to escape out of the pipe. If you cap it, the condensate will not drain properly.
Can you trap condensate?
I have found that lately it varies by manufacturer. Some even give specifics on how it should be trapped. I personally trap condensate unless it specifically says not to.
Does a condensate float switch cut voltage?
In situations where condensate overflow will cause damage or is mandatory by code the Condensate will have an approved float switch that will cut control voltage.
Can a trap be blown clear?
A trap will be blown clear if it is installed on positive side. To prevent being blown clear, the outlet would have to be higher on the outlet side of the trap to counteract SP. I don't think I've ever seen that because it doesn't work that way. Need vent.
Is a P trap required for drainage?
A P-trap is not required for proper drainage due to . the positive pressure of the air handler; however, it is recommended to prevent efficiency loss of. conditioned air. Not sure how much efficiency is lost through a 3/4" pipe, a service call for a clogged p-trap is about $xxx around here.
