AC Leaking Water Everywhere!

[Platonic Solid]

Looking at your pan, it's almost impossible to believe that the drain is perfectly clear

Yeah, there's plenty of rust in there. Not sure there's anything I can do about that.

Pour a few quarts of water in the pan and see if it goes down the drain.

Done. It all drains out as it should.

Have you checked your air filter? A plugged filter could cause lack of airflow resulting in the evaporator coil freezing up. This further reduces airflow. The coil will thaw in the off cycle and could allow water to run elsewhere besides the drainpan. This could be the source of the water leaks from the cabinet. The condensate from a condensing furnace is indeed acidic. That is why the flue system must be PVC. Metal pipe will degrade with corrosion from the flue gas.

Hmm, It's been about 6-8 months since last filter change and it is dirty. I just put everything back together with a clean filter and turned the system back ON. Not sure if I should cancel the service call now.

 

[BD1]

I would cancel service call and see what happens.

 

[Platonic Solid]

Service call cancelled. Thank you all for taking the time to respond. And dreasoner, I owe you a beer!

 

[Platonic Solid]

Just for the record, here are pics of old and new filters - both sides:

 

[rlitman]

Are those two filters the same MERV rating? The new filter has a lot less surface area (at first glance, about half).
The good news is that you can get good enough filtration in a 4" deep filter that so long as you keep the filters changed regularly, you may get many years out of the coil between cleanings. The bad news is that the filters are expensive, and as you go up in MERV rating, they last less and less long.

You could put a manometer across the filter to give you an idea of when it needs changing...

 

[Platonic Solid]

The new filter on the right is Honeywell Merv 11.
The old filter on the left is no-name-brand Merv 8.
I asked for Merv 8 at the local HVAC Supply and Mexv 11 was the closest they had. Local price was the same as online price.
This house is far from tight enough to warrant high Merv rating filters, plus the fan motor starts to give a faint high pitched whine when there's too much air restriction.
And yes, in hind-sight, I had noticed (subconsciously) the faint sound coming out of the ducts. I only really notice it when the house is quite and all are sleeping.

From the looks of the rust in the coil drain pan, it'll rust out long before it gets clogged from dust.

 

[Rock knocker]

Green rust?

 

[Platonic Solid]

Green rust?

Copper, I assume, though most of it is brown. Either way, I'll pick up some pan tablets next time I'm near HD.

 

[rlitman]

The new filter on the right is Honeywell Merv 11.
The old filter on the left is no-name-brand Merv 8.

Ok, so you went from a high surface area MERV 8 to half the area in MERV 11.
That's fine, but if you got a year out of the old filter, expect only a couple of months out of the new one. With a lower surface area, and a tighter mesh, it is going to clog up much faster. Especially since you did not have MERV 11 running before hand, so there is probably more dust in the air for it to pick up right away.

 

[Platonic Solid]

... expect only a couple of months out of the new one. ...

Great (not). That's why I wanted Merv 8 in the first place. I'll have to order them. Replacing a $25 filter every 2 months is not happening.

 

[rlitman]

Exactly. Anyway, replacing a $25 filter to avoid a service call was still a win for today.

From what I've seen, filter markup in stores is huge. They can be gotten much cheaper online. See if when you find them, you can find HD versions with more pleats. More pleats equals more surface, which equals longer change interval.

 

[Platonic Solid]

I can't start celebrating just yet. It's been running for 4 hours and it's still leaking through that left rear screw. I wonder if going to a Merv 8 would solve the problem. I assume it couldn't possibly ice up in that short time.

And it's 79° (47% humidity) in here
thermostat set to 74°
Outdoor temp in the shade is 86° (69% humidity)

 

[dreasoner]

A few other things to check: 1. Pitch on evap coil. Easy to check with a torpedo level on top of furnace casing. 2. Do have any air baffles loose or out of place on the drain pan? These would have been visible when you had the front of the coil opened up. 3. If your returns are at floor level are the grilles unobstructed? 4. You could be short on return air. You need approximately 400 cfm per ton of cooling with a face velocity across the filter of 400 fpm. Easy calculation is side of duct X side of duct/144 X fpm = cfm. Typical velocity on residential ductwork is approximately 700 1000 fpm. The pleated filter you are using will increase the surface area of the filter but as stated the higher merv rating could be hurting you. To proove this you could test the system by running without the filter to see if the water stops leaking from the coil case. Do not run the system for an extended time without a filter though. 5 You could also have a slow refrigerent leak causing the suction pressure to be too low.

 

[bonneyman]

#1 Nice job on the condensate neutralizer rig!

#2 My unit has occasional water leakage, and I keep the filter clean as a whistle. This summer I had to open up the evap coil box, and put some small aluminum chunks in the back end to get more of an incline towards the front 9where the drain holes are). Seems that whatever dirt is getting through the filter has spores in it, and they find nice moist cool channels in the drain pan and grow and clog the dang things up! Cleaning with pump sprayer, Calclean, and bottle brushes at start-up will be required every year.

#3 The rust in the pan is coming from the galvanized steel end plates of the coil. Aluminum fins, copper tubes, steel plates and moisture with any PH variance = galvanic action and corrosion. Not much can be done about it. Adjusting the fan off-timer circuit (if possible) in the furnace to it's max setting will help dry the coil after each run cycle and might help. As water doesn't sit on the coil 24/7. Just a guess on that one.

#4 Try spraying Endust on your MERV 8 filter. It helps the dustmop catch and retain more dirt - it'll do the same for your filter. Change every 4 months (one month per inch thickness)

#5 Here's the pan tabs I use. They work well, slow dissolve over a month.

http://www.amazon.com/dp/B003U45G84/?tag=atomicindus08-20

 

[acmikee]

pull your filter out for a day and see if the problem goes away. does the unit look like its icing up.

 

[Charles (in GA)]

The condensate drain is similar to what is recommended by Nortiz on their 90% condensing on demand water heaters. The one I helped my friend install simply drains outside but water heaters simply don't run for very long, especially with one person in the house, so I don't think it ever has a chance to drip at all.

The trap works I guess, but you can buy a single piece molded trap just for this purpose. I would use a PVC union to allow easy disconnection for future cleaning of the pipe.

 

[Milton Shaw]

One of my units rusted out the pan after about 19 years of use. Leaking everywhere around the unit and into the furnace. Not stopped up drain but rust holes in the pan which was not available any longer. I ended up replacing both the coil and the gas furnace under it because both were the same age and figured that the leak from the coil would have given me problems with the stove within a year or two anyway. I had replaced the compressor a couple of years ago, so I went with a R22 dry unit and charged it myself.

 

[Platonic Solid]

Just got back from HD. Picked up a 2 pack of Merv 8 filters for $40 and stuck one in. Now we'll see what things look like tomorrow morning. It was kinda cool putting it in with the blower going cause it just sucked the filter into place. It looks just like the Merv 11 - same number of pleats - about half the pleats of the no-name-brand.

I notice the Merv 11 filter states "2.5 meters per second", anyone know what the flow rate of a Merv 8 filter is?

 

[Platonic Solid]

Water started coming out on the top of the furnace again so I opened the cover to see what in looked like after 6 hours of the Merv 11 filter. Hopefully the Merv 8 will solve this problem. (No wonder it's warm in here).

 

[rlitman]

On a brand new filter, the MERV 11 should flow plenty. Maybe not after a few weeks. Get that service call. I'm betting you're low on refrigerant.

 

[Platonic Solid]

...
3. If your returns are at floor level are the grilles unobstructed?

4. You could be short on return air. You need approximately 400 cfm per ton of cooling with a face velocity across the filter of 400 fpm. Easy calculation is side of duct X side of duct/144 X fpm = cfm. Typical velocity on residential ductwork is approximately 700 1000 fpm. The pleated filter you are using will increase the surface area of the filter but as stated the higher merv rating could be hurting you. To prove this you could test the system by running without the filter to see if the water stops leaking from the coil case. Do not run the system for an extended time without a filter though.

5 You could also have a slow refrigerant leak causing the suction pressure to be too low.

3. Checked all returns and they are/were clear.

4. It's 3 Ton AC. Do I just use the main return duct? If I use the filter dim of 16 x 24 then 16x24/144 x 1200fpm = 3200cfm. If it matters: Heated/AC area = 2600 sq.ft.

5. A leak was found last May. Fill valve replaced, system charged.

 

[Platonic Solid]

On a brand new filter, the MERV 11 should flow plenty. Maybe not after a few weeks. Get that service call. I'm betting you're low on refrigerant.

Low refrigerant will cause this too? Oh ****.
I thought the condenser would stop if refrigerant was low.

 

[brewchief]

You still need the service call, in all probability you have a refrigerant leak.

Shut the A/C off and just run the fan to melt the ice, if you have to you can probably run the A/C for short stints but make sure the ice is gone before the tech gets there.

FWIW almost every unit I install gets a merv 11,13 or 16 filter and the vast majority will last a year before replacement.

 

[dreasoner]

For a 3 ton you need approximately 1200 cfm. The 16 x 24 dimension of the RA duct sounds adequate. If by fill valve you mean the service valve, that is a very common leak point. You can check for leaks with homemade soap bubble solution. Pour dish detergent INTO a squirt bottle of water. You want a soap water solution without suds to squirt onto suspected leak areas. The soap will will bubble like crazy if sprayed over a leak. Oily spots are also a telltale for leaks. Braze joints are also a common leak point.

 

[Platonic Solid]

Unit is closed and I'm running the fan to de-ice it. My plan is to run the AC tonight with the Merv 8 so I can sleep. Any risk of damage by doing this?

 

[dreasoner]

Brewchief is right on the money about deicicng the coil. The only other possibility I can think of to cause that amount of icing is a metering device such as a TXV not feeding refrigerant thru the evap coil. You are correct on most units there is a low pressure switch in the condenser to shut the compressor off with low charge. This is usually activated with a loss of charge. Your system probably has a small leak. A large leak would cause a a warm coil and not a frozen coil. Your coil temp is below freezing or 32 degrees hence it makes ice from the moisture. The tech will need a clear coil to troubleshoot the system. Hope I have been of some help to you.

 

[dreasoner]

Run the fan only to clear the coil. The system wont cool with the evap frozen. Should be ok to run the system for small increments to help cool the house.

 

[Platonic Solid]

For a 3 ton you need approximately 1200 cfm. The 16 x 24 dimension of the RA duct sounds adequate. If by fill valve you mean the service valve, that is a very common leak point. You can check for leaks with homemade soap bubble solution. Pour dish detergent INTO a squirt bottle of water. You want a soap water solution without suds to squirt onto suspected leak areas. The soap will will bubble like crazy if sprayed over a leak. Oily spots are also a telltale for leaks. Braze joints are also a common leak point.

OK, so the same as finding a tire leak. The tech that was here in May made it sound basically impossible to find a leak. Then the service valve wouldn't close after recharging the system so he replaced it. What bowled me over was the $450 bill I got shortly thereafter. Since the guy I spoke to on the phone said it was covered under warranty (even though it wasn't - according to them later on) they gave it to me for free. $450 sounds awful steep. Is R-410a that expensive?

 

[dreasoner]

I looked at the picture of the evap coil again, That black insulation in the picture is covering the remote bulb of a TXV. I think it was on this forum that I read manufactures were having a problem with an oil additive in Copeland compressors restricting the TXVs. Carrier uses Copeland scroll compressors.

 

[dreasoner]

If the service valve wouldn't seal, that would be caused by a bad schrader core. A good tech should have a tool to replace the valve cores without pulling the charge. The wholesale cost on R-410A here in Indy is about a dollar a pound. The service company probably has a minimum refrigerant charge plus typical labor charges and fees. A dye can be added to the system and allowed to circulate. A black light is used to find any leaks. A drier should be installed any time the refrigerant side of a system is opened up beyond accessing the service valves. R-410A uses POE oil which has a high affinity for moisture.

 

[Platonic Solid]

Service tech did have the magic tool to replace the valve core. I'll see what tomorrow morning looks like and go from there. Thank everyone again for your assistance.

 

[acmikee]

looking at the coil you either have a leak or bad air flow. I suspect a leak.


dreasoner I will buy all the R410 you can get for $1.00lb

 

[Platonic Solid]

It's a new day.
Last night @ 11:30 I turned the AC back ON.
Temp in the house was 79° (Humidity 50%)
Temp outside was 75° (Humidity 90%)
I set the thermostat to 76° and humidity to 58% (it's highest setting)
It was previously set at 73° and humidity at 46% (it's lowest setting)
I normally keep it at 74° but the little woman had turned it down a notch.

1:30 AM: turned it to fan only (medium speed)
4:30 AM: turned AC back ON

As of 6:30 AM (time of this posting) the only water to be seen is half a teaspoon in a bucket I setup to catch the water from the screw.

Current conditions:
Inside temp 75° (humidity 45%)
Outside temp 73° (humidity 88%)

I think I'm going to leave everything as is and see what it looks like when I get home from work.

 

[Renfrick1]

The tech can't work on a frozen system. If it's frozen when he gets there run the heat to thaw it out quick

 

[Platonic Solid]

I have a clue (maybe): Right before leaving for work the blower fan kicked into high and a few water drops exited the screw area almost immediately. I turned the system OFF, pulled the cover and saw no ice buildup. I'm holding off on the service call until I see what's up this afternoon.

Part of me just wants to put the fan on medium (instead of auto) and use it that way the rest of the summer (assuming that works). Then deal with leak repair next spring.

 

[JRC3]

Are there any flexible return lines that may be collapsed, kinked, or squashed in a wall or crawl you cant see?

Also maybe run it for a few hours with the filter out. And maybe a few hours with the filter access open so it can draw extra air. A few hours with no filter will be fine.

Have you checked the temp split?

 

[Platonic Solid]

Afternoon update:
I was fully prepared to come home to a wet mess in the garage, but not a single drop of water anywhere. House is cool and comfortable. Oddly the humidity is lower (41%) than the typical 45-50% I've been seeing.

Thermostat setting left as set last night: 76° and 58% Humidity (highest setting)
Actual indoor temp: 75° - 41% Humidity
Current Outdoor: 87° - 64% Humidity

Now if I can just convince the little woman to leave the thermostat alone, I think I'm good to go.

 

[Bronson]

It is impossible for a woman to leave a thermostat alone.

 

[Platonic Solid]

Last night:
Thermostat settings unchanged (fan speed "auto")
Fan jumps into high speed around 11:30 pm.
After a half hour of it being on high I notice the fan sounds a little more labored than usual.
(it was cooler outside than inside, 73 vs 75, but very high 99% humidity)
I get up and check for water issues and there is a 1/2 cup of water from the screw in the bucket. No visible water anywhere else.
As I pass by the hall thermostat on my way back to bed, it now reads "SYSTEM MALFUNCTION CONTACT SERVICE".
So I turned the AC OFF and put the fan on medium.
4:30 AM I turned the AC back ON and the "SYSTEM MALFUNCTION ..." message goes away.

 

[dreasoner]

Obviously something has changed in the system. The water from the screw hole has to be blown off from the coil or out of the pan. What kind sensors does the stat use use to trigger the malfunction message? - amp draw, temp sensors, airflow sensors? Does the I/O manual say anything about air baffles of any sort for different duct configurations?
I was on an American Standard furnace that tripped the hi limit because it was missing a baffle. It was a mult-poise furnace. Is there a default algorithm for the stat or tech troubleshooting section in the stat I/O manual or software you could access?
Just throwing out ideas to see if something sticks. Obviously has to be related to airflow and coil conditions.