Gas Furnace Condensate Drain Line

[LLigetfa]

This is a cautionary tale of what not to do (or don't put all your eggs in one basket).
Initially my furnace installer ran 1/2" PEX over to my sump pit some distance away along the floor in my crawlspace for the condensate drain. Later, when I added a humidifier, I Teed into the same line rather than add a second line. To make matters worse, I also Teed the drain from my R/O into the same line. When I had central A/C installed the tech ran a second drain line.

Well, the line plugged after the furnace and the R/O since it was under pressure, backed up into the furnace causing it to fault and shut down. It also started to flood my crawlspace where we store items. To make matters worse, the saddle valve that supplies the water to the R/O had stripped its threads and could not be shut off. I had to shut off the water for the whole house. This happened Saturday at bedtime, before we were to leave town Monday on a two night outing. I managed to unclog the drain to get the furnace going and went to bed but the furnace was still dripping.

That left me with only Sunday for a more permanent fix. I bought 100 feet of PEX and a water heater drain pan to lay under the furnace to catch the drips and ran to R/O drain into it temporarily so I could turn the water back on. I planned to run the R/O drain overhead since it is pressurized and does not rely on gravity leaving one less line to run across the floor. Meanwhile the wife changed her plans Monday morning so we could leave on Tuesday giving me one more day to work on it.

The furnace guy who was scheduled to come on Monday didn't show but I was was confident that the water heater drain pan was catching the drips. I still need to replace the saddle valve but since it is self-piercing I wonder if I need to plug the hole in the copper pipe and make a new hole.

 

[Reach4]

I still need to replace the saddle valve but since it is self-piercing I wonder if I need to plug the hole in the copper pipe and make a new hole.

I do not think so. With some pipes, you are instructed to drill a hole before attaching the saddle valve.

https://www.siouxchief.com/docs/def...97-series---saddle-valves---instruction-sheet says

.... OR if the supply line is steel, brass, PVC or CPVC, the supply line must be pre-drilled with a
1/4" hole where the valve is to be located.

When I drilled a hole in galvanized, it was a lot smaller than 1/4 inch. It just has to clear the needle, so I would look at 1/4 as an upper limit.

 

[Sponsor]

 

[LLigetfa]

I wonder if I could find the same model of saddle valve if I could replace it and not have to plug the old hole.

 

[Reach4]

Yours is a lot more robust-looking than the one that came with my AprilAire.

Why swap out the existing saddle valve?

But even if you do swap out the saddle valve, you should be able to put the new one in the same spot. If the new one is self-piercing, just have the needle fully extended when you position the valve.

 

[Reach4]

I planned to run the R/O drain overhead since it is pressurized and does not rely on gravity leaving one less line to run across the floor.

I think the performance of the RO would be a function of the difference in pressure between the input water and the drain. So if the drain line has to climb, that could reduce production slightly-- unless the drain line did not empty, and you would get a boost from siphon action.

 

[LLigetfa]

Why swap out the existing saddle valve?

The threads on the valve stem are stripped so it cannot be shut off.

I wondered if the piercing needle provided the seal between it and the pierced hole or if it has its own valve seat. Obviously, a predrilled saddle valve would not rely on the hole for a seat.

 

[LLigetfa]

The R/O also has a permeate pump to boost production. The R/O drain runs up one foot to the underside of the floor above and . It feeds into 1/2"PEX that runs 30 feet overhead and then drops 4 feet to the sump pit.

 

[Reach4]

The threads on the valve stem are stripped so it cannot be shut off.

I wondered if the piercing needle provided the seal between it and the pierced hole or if it has its own valve seat. Obviously, a predrilled saddle valve would not rely on the hole for a seat.

Rubber seal contacts the outside of the pipe. Seal is square in these:

https://www.supplyhouse.com/Wal-rich-4415002-Self-Tapping-Saddle-Valve-Lead-Free

https://www.homedepot.ca/product/sioux-chief-1-4-inch-x-1-4-inch-lead-free-brass-compression-x-compression-self-tapping-saddle-valve/1001002625

Interestingly, https://www.supplyhouse.com/Aprilai...040-Aprilaire-Humidifier-Solenoid-Valves-4001 does not seem to show such a seal. I was thinking there was one when I installed my saddle valve.

 

[Sylvan]

I never, ever used a saddle valve (piercing valve) I did testify in court against a general contractor who used one, and it caused a leak.

Ideally, use a ball valve and add a reducer fitting, and use flare or compression if you're using smaller diameter tubing

 

[LLigetfa]

Rubber seal contacts the outside of the pipe.

Yes but does it also act as the valve seat? It does not leak between the pipe and the saddle, just doe not shut off.

 

[Reach4]

Yes but does it also act as the valve seat? It does not leak between the pipe and the saddle, just doe not shut off.

It does not. The valve seat is hidden in the brass.

 

[Sylvan]

I never, ever used a saddle valve (piercing valve) I did testify in court against a general contractor who used one, and it caused a leak proving it was against the plumbing code.

Ideally, use a ball valve and add a reducer fitting, and use flare or compression if you're using smaller diameter tubing

 

[LLigetfa]

The furnace guy who was scheduled to come on Monday didn't show but I was was confident that the water heater drain pan was catching the drips.

The furnace guy still has not come. I guess they are busy with no-heat calls and since they know that I have the water heater drain pan to catch the drips, it is not a high priority. It has been going down to -25C at night so I feel sorry for the no-heat customers. Even if I had a no-heat issue with the furnace, I have wood heat as a backup which works well as long as I still have power. I have a small backup generator for when the SHTF.

I was not aware that a saddle valve is not to code but I don't want to cut out the section of pierced pipe and sweat in a Tee and a ball valve. I also have a saddle valve for my humidifier that I'm afraid to touch as long as it still works. I picked up a new saddle valve from my furnace guy that looks more substantial than what I see on the big box store shelf and will replace the one with the stripped threads. Mind you, that bad one also looks more substantial but then looks can be deceiving.

 

[Reach4]

If half-inch copper, see https://dahlvalve.com/?s=valve+tee

 

[LLigetfa]

Rubber seal contacts the outside of the pipe. Seal is square in these

There was corrosion where the narrow steel piercing needle inserted into the wider brass valve stem and that chewed up the rubber seal.

The dripping from the the bottom of the furnace mostly abated as the insulation dried out. Most of it was the water from the R/O. There is still a small drip of condensate leaking outside the drain but it is such a small leak that it evaporates from the make-shift water heater drain pan. It looks like it has been leaking for some time evidenced by the amount of rust that formed. I cancelled the furnace tech (that still hasn't come) and will seal up the leak after the heating season.

 

[Fitter30]

If there's some movment in the piping . could cut out the hole the valve made..copy and paste
us/en/push-to-connect/push-to-connect-valves/push-to-connect-supply-stops/tee-stop

 

[LLigetfa]

There was corrosion where the narrow steel piercing needle inserted into the wider brass valve stem and that chewed up the rubber seal.

Probably the brass or alloy (it is yellow when the patina is removed) stem cracked from the insertion of the steel piercing needle and then disintegrated. Note the deterioration of the threads. The rubber seal was very hard as well.

Unlike the saddle valve on my humidifier that has never been shutoff since the day it was installed, this one on the R/O gets turned off & on twice each year whenever I change filters do I guess I should install a proper ball valve. Fortunately it is exposed between the floor joists so I have room to cut and spread the copper pipe and sweat in a Tee. The original saddle valve was a C-style aluminum clamp compared to the replacement that has a steel saddle that could rust away if the pipe was prone to sweating. This branch runs to the kitchen sink, so it does not run enough cold water to sweat.

Here is a picture of it.