Rheem RGRL Condensate Drain Problem

[tommyespo]

Hello Everyone,

I work in sales at a wholesaler in NY. We distribute Rheem equipment and the factory is giving our service tech the run around regarding a problem one of our customers is having with an installation of a Rheem RGRL07EYBGS furnace.

Here are the commisioning notes that we sent to Rheem:

Parameter Measured Allowed
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Temperature Rise
Low Fire 40 25-55
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Temperature Rise
High Fire 52 35-65
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Pressure Switch
Vacuum 1.5" 1.08" or higher
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Manifold Gas Pressure
Low Fire 1.7" As factory specified
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Manifold Gas Pressure
High Fire 3.5" As factory specified
----------------------------------------------------------------------------------------------------

The furnace has the following problem:

1) The pressure switch vacuum was measured at 1.5 inches when the furnace first fires. When operated at High Fire for about 10 to 15 minutes, water gurgling sounds are heard at the exhaust discharge port at the top of the furnace. The pressure switch vacuum drops down to as low as 0.95 " and is very unsteady (fluctuating between 0.95 and 1.20 inches.) The furnace kicks down to low heat on the pressure dips. (The fan kicks down and the flame reduces, causing a "thump" sound. The LED's on the circuit board also wiggle when the fan changes speeds. The gas valve "click" can be felt on the gas supply pipe.) Eventually the center LED will begin to blink twice (code 2). Tests above seem to rule out all the causes for blink code 2 shown in the install manual trouble shooting section. (ie: Hoses and switches are correct, vent has ample flow, the control module is functioning correctly, it was not windy, and our elevation is less than the 2000' base line). Our problem seems to be an exhaust restriction due to significant condensation that cannot drain through the furnace, especially when the induced exhaust blower is run at high speed. The blower motor seemed to be running hot. It was quite warm to the touch.

We had him check all the hoses leading into the condensate trap, as well as the pipe coming out of the trap. All were free of kinks, and had a definite downhill pitch. All had flow. We had him double check the furnace to see that it was level. Turning off the power to the furnace for about 5 seconds, then turning it back on again will clear the problem, but only for about 10 minutes.

We had him disconnect the drain tube at the bottom of the transition "t" and check for a blockage (pvc filings or residual plastic left over from when the fitting was injection molded) and that fitting is clear and free of debree. Right now the condensate line is running out of the furnace to a "t" with a 6" tall drain vent tube vertically and the other side of the "t" is running into a bucket so that we have as little restriction as possible to the drain.

The venting is run horizontally from the basement out of the property. All venting is 3" PVC from the top of the furnace all the way out of the house. Both intake and exhaust EACH contain about 15' of straight pipe with EACH having 4 45 degree fittings. There are no 90 degree elbows in the vent system.

As of now the furnace has dip switch number 7 set to keep the furnace in low fire mode. It limps along so that the home owner is not with out heat, but at night it's impossible to keep the house over 65 degrees with the cold temperatures we've been having.

The contractor doesn't know what else to try and the Rheem factory techs have been "working on this" for 2 days without any feedback. If anyone has any suggestions, please let me know. We'll give the contractor any parts that he needs to "try" anything that might solve this problem.

I would really appreciate any feedback or suggestions. The home owners are older folks and I'd like to settle this issue before we have another snow storm at the end of this week.

Thank you,

Tom Esposito

[b26440510]

no ideas, but my Rheem RGJF manual says that 3" should be converted down to 2" before sidewall penetration. There are different requirements based on BTU of furnace. There should be a vane in the air intake tube. The two pipes must be in the same pressure zone. Intake opening should be 4" from sidewall, exhaust opening should be 12" from sidewall and 4" apart. No elbows or screens on openings.

[tommyespo]

Here are a few images:
http://www.brothers-supply.com/rgrl/Condensate_Connections_1.JPG

http://www.brothers-supply.com/rgrl/Condensate_Connections_2.JPG

http://www.brothers-supply.com/rgrl/Condensate_Connections_3.JPG

http://www.brothers-supply.com/rgrl/Discharge1.JPG

http://www.brothers-supply.com/rgrl/Gas_Pipe.JPG

http://www.brothers-supply.com/rgrl/Interior.JPG

http://www.brothers-supply.com/rgrl/Vent_Pipes.JPG

[jpb2]

Does it operate any differently with the door off ? The drain and vent all look within spec

[b26440510]

Looks decent to me but I'm just a homeowner. Gurgling would normally indicate an airflow problem of some sort, at least in plumbing.

Did you try using a stethoscope to narrow down exactly where the gurgling is coming from?

If you pour a bunch of water in the vent stack just after the furnace's condensate trap does it drain fast? If you temporarily disconnect your condensate plumbing from the furnace does it still have problems?

You might want to run a snake camera down the exhaust port in the furnace and inspect the condensate system.

[keeplearnin]

If you hear gurgling then there is water getting trapped in the inducer fan motor housing. Not being there with my hands on the unit I would say that that is where your problem is coming from. It just takes a little bit of water to slow the fan down enough to shut it down. I would go through the drain lines and make sure everything is draining properly.

[captube]

Rheem have any technical bulletins out on that inducer.

especially when the induced exhaust blower is run at high speed. The blower motor seemed to be running hot. It was quite warm to the touch.

Technical questions are not allowed to be discussed in this open forum, so you won't be able to go to far with this.

[big sky hvac]

Are you sure there is adequate slope on the exhaust pipe back to the furnace? I would also put a 90* elbow on the intake so it can't recirculate exhaust into the combustion air.

[tommyespo]

no ideas, but my Rheem RGJF manual says that 3" should be converted down to 2" before sidewall penetration. There are different requirements based on BTU of furnace. There should be a vane in the air intake tube. The two pipes must be in the same pressure zone. Intake opening should be 4" from sidewall, exhaust opening should be 12" from sidewall and 4" apart. No elbows or screens on openings.

You're correct. I posted a few pictures and one of them shows that he has correctly installed the venting per the manual.

[tommyespo]

Does it operate any differently with the door off ? The drain and vent all look within spec

Agreed. That's the first thing we asked. The furnace acts the same way with the door off, so it's unlikely that his intake air is the problem. To your point, it is a common problem / mistake.

[tommyespo]

Did you try using a stethoscope to narrow down exactly where the gurgling is coming from? The gurgling is in the white tube inside the furnace above the transition elbow, but can be heard outside the furnace with the door on.

If you temporarily disconnect your condensate plumbing from the furnace does it still have problems? I mentioned in the first post that we had him disconnect the drain from the transition elbow inside the furnace and check the elbow for a blockage. He also blew out the line that runs from the elbow down into the trap and out of the furnace. Additionally, he has disconnected the drain tube outside the furnace from the pump and it's currently just empting into a bucket.

You might want to run a snake camera down the exhaust port in the furnace and inspect the condensate system. It's a short distance and he has been able to inspect everything from the transition elbow out of the furnace. It is clear of debris

I believe that it's safe to say that the passage way is clear from the inducer motor through the condensate line and exhaust pipe

[tommyespo]

If you hear gurgling then there is water getting trapped in the inducer fan motor housing. Not being there with my hands on the unit I would say that that is where your problem is coming from. It just takes a little bit of water to slow the fan down enough to shut it down. I would go through the drain lines and make sure everything is draining properly.

If you wouldn't mind reading the previous post to b26440510, I think the contractor has done enough to insure that the drain side of the condensate line is clear.

Re inducer motor: Do you believe that the motor could be bad and that's the reason why the condensate builds up?

[tommyespo]

Rheem have any technical bulletins out on that inducer. Our tech guy doesn't remember seeing anything like this in the bulletins. I've started to read through them myself and I hope to get through the rest of it tomorrow


Technical questions are not allowed to be discussed in this open forum, so you won't be able to go to far with this.I just found the requirements for professional membership. I'll need at least 15 posts to apply for access to the technical forums and I'm only half way there.

PLEASE FORGIVE ME FOR POSTING SO MANY TIMES IN THIS THREAD.

[snewman24]

It's probably not related to the problem, but have the factory reps said anything about the horiz. direct-vent air intake not having the tee and condensate drain trap that is required in the installation manual? I don't see one installed in the pics.

http://i5.photobucket.com/albums/y174/bashful24/Scan10236.jpg

[tommyespo]

Are you sure there is adequate slope on the exhaust pipe back to the furnace? I would also put a 90* elbow on the intake so it can't recirculate exhaust into the combustion air.

We believe that there is enough slope in his exhaust pipe. One of the pictures shows a 45 directly at the top of the unit. In addition they have pitched every other straight run. Please remember that the total length of straight pipe for the exhaust is only about 15'.

Re elbow: 10 years ago I would have agreed with you, but the Rheem installation manual says not to add any elbows or screens. Our guys have followed the manual and there hasn't been a problem before this.

[tommyespo]

It's probably not related to the problem, but have the factory reps said anything about the horiz. direct-vent air intake not having the tee and condensate drain trap that is required in the installation manual? I don't see one installed in the pics.

Rheem hasn't responded at all except to say that the problem is unusual and they have escalated our request since it's already been 2 days :whistle: Apparently empathy to inadequate amounts of heat in cold weather isn't a strong point with the folks in Arkansas.

I agree that it's probably not related, but I'll have the tech guy ask Rheem when they finally get back to us. Since the furnace acts the same with the door on or off I don't believe that the intake side is the problem here. I can't believe that another day has passed and Rheem hasn't made even one new suggestion.

[snewman24]

This from pg.24 regarding standard horizontal direct-vent installations:
http://i5.photobucket.com/albums/y174/bashful24/Scan10237.jpg

[tommyespo]

Does anyone believe that the inducer motor could be to blame for the condensate drainage problem? I don't want to put this poor guy through more work than is necessary. He's been back to the homeowner's place at least 3 times since the install so I don't want to waste his time.

Thanks again, guys.

-Tom

[tommyespo]

This from pg.24 regarding standard horizontal direct-vent installations

Thanks, snewman. I appreciate it.

I have read that before and while I believe in following the manufacturer's recommendations to the letter. I don't think that's currently the issue. We've had dry weather since it snowed a whole bunch early last week. The relative humidity is in the high 30's / low 40's.

[b26440510]

well, I was actually saying to inspect the entire condensate system with the snake cam, including the inducer blower.

From what I can gather, it sounds like the inducer is probably the only "active" part in that condensate system, everything else is pretty static (non moving).

Perhaps there's a mfg defect that is either blocking the drain port or the blower wheel is getting into the water stream.

[tommyespo]

Heard back from the factory today. There are 3 possibilities:

1. The choke ring in the draft inducer motor is allowing air leaks.

2. The condensate trap itself is allowing air leaks.

3. The factory tubing that routes the exhaust from the draft induced motor to the discharge port allows air leaks.

The reason that they believe these are the possibilities is that upon initial fire the vacuum at the switch is 1.5", but steadily drops down to 0.9" over the course of a few minutes. These air leaks allow "too much air" to flow in the tubing which impedes the water trying to move through the drain system and causes the build up. Rather than have us take parts out of stock (which they say could have the same problems!) the factory is over-nighting the latest and greatest parts to us which we'll have tomorrow morning.

It's nice that they are over-nighting the parts, but I will tell the factory rep that I'm disappointed that we won't be able to offer the parts until the 4th day after we reported the problem to them. Also, what does the need for factory fresh parts say about the usefullness of our current parts inventory?!

::shaking my head::

-Tom

[keeplearnin]

So just for my clarification since the contractor went through all of the drains and it's not draining properly and the factory is sending parts to help the drainage would it be safe to say it might be a drainage problem? If air is getting trapped in the housing and it's holding water in the housing I think maybe there might be a drainage problem.

[tommyespo]

So just for my clarification since the contractor went through all of the drains and it's not draining properly and the factory is sending parts to help the drainage would it be safe to say it might be a drainage problem? If air is getting trapped in the housing and it's holding water in the housing I think maybe there might be a drainage problem.

Yes. Since the condensate isn't able to get out of the unit at the appropriate rate I would say that the air leaks are causing a drainage problem. It's a factory defect, not anything that my customer did wrong when he installed the unit at the homeowner's residence.

If I made a statement in one of my earlier posts stating that it wasn't a drainage problem then I apologize for being unclear. When statements were made about drainage I assumed that the reference was made regarding a blockage from debris or a hose kink.

[b26440510]

Good luck. Hopefully for the customer it will all be good once the "fresh" parts are installed. Maybe this is related to the service bulletin someone mentioned. If not, may be time to swap out the furnace, so the home owner can feel better.

I like those 3" PVC pipe hangers in the photo. I wonder if those were custom made or something you can buy. Looks better than using nailing straps.

I've been looking for some kind of support that grips the 3", since my install manual says that horizontal and vertical runs are to be supported every x feet.

[jpb2]

Thanks for the info. I'm a Distributor too. Never had one act like yours though

[tommyespo]

I like those 3" PVC pipe hangers in the photo. I wonder if those were custom made or something you can buy. Looks better than using nailing straps.

I've been looking for some kind of support that grips the 3", since my install manual says that horizontal and vertical runs are to be supported every x feet.

The contractor fabricates the straps out of aluminum bar. He makes them in his shop. He also makes the spacer between the 2 pipes out of a high density foam block. He said that he makes them in batches using a hole saw. Then he cuts the blocks in half with a little band saw.

[tommyespo]

Thanks for the info. I'm a Distributor too. Never had one act like yours though

We try to do the right thing. I really wanted to help this guy out. He's a personal friend

[keeplearnin]

Make sure you tell us the verdict when it's repaired.

[gs1230]

Recently had a the same problem with the same furnance, all venting was within specs. Furnance ran fine till temp dipped below 25 then it would lock out on pressure switch. Finally revented to concentric kit and no more problems. Reps were telling me it was Radon gas in the house or pinched wiring harness I called BS.

[jpb2]

We try to do the right thing. I really wanted to help this guy out. He's a personal friend

Nice. Thats the relationships we build here too. I take my customers business personally.

[keeplearnin]

Good info to know thank you

[Twilly]

Twilly says crap in the bottom of tee. that fitting is not full bore

[Ghostrider67]

I agree with Twilly. I had a Brand new Rheem installation with shavings from the pvc on the inside running back to the inducer tee and clogging up just before the hose. The installers used a hacksaw to cut the pvc but never cleaned the inside shavings out.

[jpb2]

There is a vane in that fitting. Good thought.

[tommyespo]

Update:

Everything from the draft induced motor out of the furnace was changed including the drain "t" that Twilly mentioned. Unfortunately, the situation remained. As a last resort, the exhaust orifice was removed and the situation went away.

There is no clear explanation for why this worked, but everyone at the factory was sure that it would. The furnace is now the equivalent efficiency of the RGRK line (92.5% efficient). We offered to remove the furnace so the homeowner could buy something that would yield a 95% efficiency from a different manufacturer, but they declined. They were happy that the issue was resolved and how the contractor stayed on top of it to work with them until it was.

I know my response is probably frustrating, but I don't have direct access to the Rheem support people. Only our tech guy speaks to them. He wasn't happy with the way that this was resolved either, but the issue is closed. I wish I could post complete information, but this whole thing is a sore point around here now and I'm just going to let sleeping dogs lay.

I want to thank everyone for their time and responses. Please message me if you need any Rheem info and I'll do my best to get it to you. I now have professional member access and can upload files.

Have a great weekend,

Tom

[sktn77a]

Tommy:

What do you mean "removed exhaust orifice", and how would that reduce the efficiency from 95% to 92.5% (the Rheem specs for the RGJF are 90%-94.8%, depending on size).

[hvac-learning]

Think i would have pulled the hose off the secondary exchange and see how fast the water drain out. the look at the unit to see if it leaning away from the drain port .. maybe holding too much water in the secondary do to not bein level or pitched away from drain port

[tommyespo]

The furnace that was installed is a Rheem RGRL series, which is 95% efficient. In line, between the draft induce motor and the top of the pipe where the exhaust exits the furnace is, to put it plainly, a plastic disc with a hole in it. This disc or "exhaust orifice" creates resistance to the exhaust leaving the furnace. The resistance forces the exhaust to remain in the secondary heat exchanger for a longer period of time, allowing more heat to be extracted, and the furnace to yield a 95% efficiency.

When the exhaust orifice is removed, the efficiency of an RGRL drops to about 92% which is the same as the RGRK models.

The customer was given a discount and the original furnace remains in place.

[hvac-learning]

Look at the gas pipe drip leg in pic 1 .... looks close at the cap (distance from gas line to heater then up around the tee) R U sure the unit was set level or slightly pitched twards the drain?

[tommyespo]

Think i would have pulled the hose off the secondary exchange and see how fast the water drain out. the look at the unit to see if it leaning away from the drain port .. maybe holding too much water in the secondary do to not bein level or pitched away from drain port

That's a valid point. The furnace was checked for level a few times, but the amount of water coming out of the secondary heat exchanger was never measured to see if it was inline with the 1 gallon per 100,000 BTU expectation. When the orifice was removed, the condensate drained out perfectly. With the orifice in place, the condensate would back up past the joint between the black condensate "t" and the white pipe going up to the exhaust discharge port.

[hvac-learning]

have not got a chance too really see 1 of these unit yea. but inet somethigh simple love to see the data sumittal cut for this unit. think i`ll try to find it on line

[sktn77a]

The furnace that was installed is a Rheem RGRL series, which is 95% efficient. In line, between the draft induce motor and the top of the pipe where the exhaust exits the furnace is, to put it plainly, a plastic disc with a hole in it. This disc or "exhaust orifice" creates resistance to the exhaust leaving the furnace. The resistance forces the exhaust to remain in the secondary heat exchanger for a longer period of time, allowing more heat to be extracted, and the furnace to yield a 95% efficiency.

Ah, OK - the RGJD was in another post. I guess restricting the exhast venting was a kludge to get the efficiency up, with somewhat predictable results in a furnace not designed for it!

[snewman24]

Ah, OK - the RGJD was in another post. I guess restricting the exhast venting was a kludge to get the efficiency up, with somewhat predictable results in a furnace not designed for it!

It really doesn't do much to instill confidence in anybody that Rheem is doing careful R&D and field testing before putting a furnace on the market.

[sktn77a]

Agree (I think). It's disappointing that Rheem didn't thoroughly test this out - I think they got caught with their pants down on 95% efficient furnaces when the tax credit came along. I have 3 Rheem systems in my house, two are RGJD furnaces (92%-93% efficient). I got the complete tax break ($1500) on the two A/C condenser units so I wasn't too bothered by the 93% vs 95% efficiency. I guess a lot of people are, though, and they've lost siginificant sales by not havuing a 95%+ furnace.