# Luxaire Furnace problem



## yuri (Nov 29, 2008)

Post a pic of the switch and hose and how it drains to the header box or trap. Hose should have NO traps in it. Should drain down with no sags, kinks to the trap or collector box.


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## kenmac (Feb 26, 2009)

if that's an 80% faf..;.maybe someone's vented it incorrectly causing too much condensation


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## Orlo (Sep 22, 2010)

The run for the vents (exhaust and makeup) are about 30' long. Could this be the problem? If so, what is the recommended maximum distance for the exhaust?


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## Orlo (Sep 22, 2010)

I'll post pictures later today. I removed the tee and drain. The switch did not have a drain from it. I added one to see if it would help get rid of the water condensation... didn't work. There are two ports where water can be drained from the exhaust fan - one near the top of the exhaust leg and one at the lowest point on the fan. The one which was used when the furnace was installed (and still is today) is the one near the top of the exhaust leg. I've tried connecting the drain to the lower port, but the problem still occurs. The condensate trap is clean. After the furnace runs for extended periods of time, there is a considerable build up of condensate in the bottom of the fan. I know this because when I tried to connect the drain to the lower port on the exhaust fan, a lot of water drained from the fan. This leads me to believe the exhaust vent may be too long (~ 30').


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## kenmac (Feb 26, 2009)

can you post a pic of the vent ? The water should drain from the fan housing into the condensate box. I would check for blockage. With hose removed . does water come out of the fan housing ?


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## Orlo (Sep 22, 2010)

The run is mostly horizontal - approximately 30 feet with a total vertical rise of about 3 feet.


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## beenthere (Oct 11, 2008)

Check if the pressure switch port has a small hole in its port near the body. If so, make sure the hose is NOT covering it. If its covered, the switch will draw the water up the tube.


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## Orlo (Sep 22, 2010)

There is no hole in the port.


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## beenthere (Oct 11, 2008)

Next time you have the furnace running, check the incoming air temp, and the supply air temp, make sure it is atleast 40 degrees hotter leaving the furnace, then it is entering the furnace.


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## Orlo (Sep 22, 2010)

Will do. Generally, the supply temperature is whatever the OA temp is because it is piped with an OA supply line. I haven't measured the supply air temperature, but I would guess that it is in the range of 90 - 100 F. During winter operation this would give a delta of 60 - 70 degrees. The pressure switch fills with water in about 2 days with the furnace running on a typical winter day (OA = 30 F).


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## Orlo (Sep 22, 2010)

*More Pictures*

Here are some more pictures. The drain from the blower is connected to the outlet side of the exhaust. I tried connecting it to the port on the bottom of the blower (shown in one picture), but it didn't help.


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## kenmac (Feb 26, 2009)

looks like that hose needs to be connected to the lower port on the vent motor. With the furnace in operation.( when your having this problem ) Have you pulled the plug at bottom of the motor to see if water runs out ?? there should be small amount of neg. perssure on that switch. So, it can't be sucking water into the switch


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## Orlo (Sep 22, 2010)

I agree that the water shouldn't be coming from the pump because of the negative pressure, but when I drain the water from the pressure switch, it comes from the port that is connected to the vent pump. Since the pressure switch is just a diaphragm, I don't think the water can pass from one side of the diaphragm to the other (I only get water from the one port). This is driving me nuts. I can't understand where the water is coming from. In response to your first comment - yes, I do get water draining out of the vent pump when I take the plug off the bottom port. But if the water isn't coming from the pump, could it be condensing inside the pressure switch?


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## beenthere (Oct 11, 2008)

I was talking about the return air from your house, and the supply air to your house. Not the intake and exhaust for combustion.


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## kenmac (Feb 26, 2009)

I just can't remember seeing a drain connected that high up on the draft motor with faf in the horizontal position


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## yuri (Nov 29, 2008)

There are 2 drains Ken. One for the collector box and the other for condensate that runs backwards down the exhaust pipe especially in the off cycle. Has to be at the top of the inducer fan to prevent water going back into it. Does not matter if it is an upflow or horz unit, looks upflow to me. The bottom one in the inducer will always have an inch of water or less in the inducer as the hole in the back of the inducer fan is not flush with the bottom of the fan AND the hole in the collector box so it gets trapped there. Those fans are designed to spit a bit of water.

Do you run your furnace fan continuosly?. How old is the furnace?. When did this start happening?


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## yuri (Nov 29, 2008)

Try a new pressure switch. Possible that the diaphram has a TINY hole in it and allowing flow thru the body of the switch. Normally there is no flow if the diaphram is intact. Will still work with a tiny hole in it.


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## kenmac (Feb 26, 2009)

I don't have a luxaire . I have 3 drains. 1 at the bottom of the vent ( vent is set up a little different)1 at the collector box & 1 at the bottom of the motor. Maybe he's missing a drain. Do you have the install instructions ??


I haven't installed any luxaire so I'm just guessing :confused1:about a 3 rd drain


Ya know, just scratching my bald head trying to come up with a fix to his problem..


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## kenmac (Feb 26, 2009)

yuri said:


> There are 2 drains Ken. One for the collector box and the other for condensate that runs backwards down the exhaust pipe especially in the off cycle. Has to be at the top of the inducer fan to prevent water going back into it.


 

I'm thinking ( & may not be correct ) that some water is by passing this upper drain & getting into the motor housing..

it's difficult sometimes to diagnose these things behind a computer:wallbash:


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## Orlo (Sep 22, 2010)

The next time the furnace kicks on, I'll try to measure... weather today and tomorrow will be in the 80s. But I'm curious as to what the temperature delta indicates.


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## yuri (Nov 29, 2008)

I have seen a few of them. They are York clones (owned by York). No 3rd drain. Beenthere is a Yorkie and should know it well. If it is running too cool then it may be hitting the dewpoint inside the switch and condensing. He needs to do a proper temp rise test and find out.


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## Orlo (Sep 22, 2010)

The furnace fan does not run continuously. The furnace is about 7 years old. The problem began about 3 years ago. The reason I didn't catch it before that was because I was burning wood as my primary source of heat. The gas furnace did not run much for the first 3-4 years. I'm tired of burning wood, so I've been using the furnace as my primary heat source. The service techs did not know how to fix it and I got tired of paying them $65 for showing up and not being able to fix it. I've been getting by with emptying the water from the switch when it begins to stop heating, but there has got to be a way to fix it.


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## yuri (Nov 29, 2008)

You REALLY need a new switch now as the water can damage it/lose it's sensitivity and make it inaccurate and UNSAFE. In order to get water inside it there has to be one of three scenarios:

1) Drain in from being lower than inducer (NO)
2) Flow thru it from ruptured diaphram (Maybe)
3) Moisture condensing inside it because the basement is COLD and it hits the dewpoint inside the switch and condenses (not likely but possible) or the smoke/exhaust temp too low and hitting dewpoint. If it was hotter in may not condense.
4) Cracked heat exchanger and fan forcing humid air inside the switch on the off cycle if fan is running

Seems strange as it probably is a negative pressure switch and not have fumes there but vacuum when running. Some brands have a positive pressure switch, Beenthere would know if it is negative.

You won't get a good temp rise test if it is that hot outside. Wait until it is 65 ish or do it early in morning or late at night.


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## beenthere (Oct 11, 2008)

That was probably a first reversion of that unit then. 

They also had a problem with the condensate over whelming the inducer. The drain fitting didn't work as well as it should have on the first revisions(post 12, pic 3 shows the fitting I'm talking about).

Had to add a drip tee in the exhaust of most of them(the ones with horizontal flue runs).


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## kenmac (Feb 26, 2009)

Orlo said:


> yes, I do get water draining out of the vent pump when I take the plug off the bottom port. But if the water isn't coming from the pump,


 

This is what makes me think that water is somehow by passing the tube at the vent & being picked up be the blower fins & slinging it to the switch

or. the collector box (inside the furnace) has a hole & gets into the fan there

Of course ths is just a guess from behind a computer screen


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## yuri (Nov 29, 2008)

The port/nipple on the inducer is horizontal so it would be very difficult to sling water into it. The inducer wheel sails it off into the exhaust pipe. The Lennox G61 is so quiet you can hear it spitting/slinging water so they are designed to do that. Mids have condensing problems in that switch if the flue gas gets too cool due to cold chimney or uninsulated single wall venting. Never run into it on a high.

Good logic skills you have. I try and encourage outside the box thinkin to my apprentices with little success. They like to think about socializing. Guess you have to be born with logic skills.:yes:


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## kenmac (Feb 26, 2009)

yuri said:


> The port/nipple on the inducer is horizontal so it would be very difficult to sling water into it.
> 
> 
> Yep, I thought about that also.
> ...


 

Thanks,
you have to be able to think outside the box.. Sometimes,,This stuff will throu you a curve ball


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## Orlo (Sep 22, 2010)

The furnace is an upflow, not horizontal.


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## kenmac (Feb 26, 2009)

yuri said:


> You REALLY need a new switch now as the water can damage it/lose it's sensitivity and make it inaccurate and UNSAFE. In order to get water inside it there has to be one of three scenarios:
> 
> 1) Drain in from being lower than inducer (NO)
> 2) Flow thru it from ruptured diaphram (Maybe)
> 3) Moisture condensing inside it because the basement is COLD and it hits the dewpoint inside the switch and condenses (not likely but possible) or


 

After sleeping on this.I just don't think that motor would sling water in that switch......... I'm going with option # 3 It is metal.. Most of these switches are now plastic. Like you stated ,,due to moisture in the switch...the switch needs replacing... It wouldn't cost much to replace the switch & see if that solves the problem. I still think that 1 of those drain tubes needs to be connected to the bottom motor housing port. If he had installation instructions it would help


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## fabrk8r (Feb 12, 2010)

Now that it has been confirmed that this is an upflow configuration, the condensate drain line from the draft inducer motor looks to be set up for a horizontal application.


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## Orlo (Sep 22, 2010)

*Correction*

I made a mistake on one of my previous posts. The water is condensing on the side of the pressure switch nearest to the induction blower, not the burner box. Because I have a clear poly hose connected to the switch, I can see that the water is not blowing into the switch from the induction blower - it is just condensing in the switch. So now what?


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## Orlo (Sep 22, 2010)

The problem was resolved when the switch was replaced. After talking with a representative from Luxaire, the problem was identified in the switch. Apparently if there is not enough airflow through the switch, then condensation builds up in the switch. Replacing the switch with one that allows more flow through it solves the condensation problem. Thanks for everyone's input. It's nice to have this behind me.


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