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mepadre

join:2003-08-15
Waterloo, ON

Sump Pump - Discharge riser freezing

Hey all,

So, last year you might recall that I had some issues with my sump pump failing causing some flooding and rehabilitation of a finished basement. I have since added a backup battery powerd pump in addition to replacing my main pump with a very high grade Myers pump and a the addition of a high water alarm if, for some reason, both pumps fail.

Ironically, given all of those items, I had a situation last night that basically rendered my 2 pump system non functional. I am in Southern Ontario so the weather has been -15C approximately for the past few days.

As I have 2 pumps connected to 1 discharge, the install required 2 check valves. My old pump system did not have a check valve and the riser drained back in the pit through the pump after each cycle. The new system keeps that water from flowing back and also 'prevents' a backflow from the storm drain.

Basics on the system... 2 pumps wye into a single 2" discharge pipe. This rises about 8 feet next to the concrete wall in the 'fruit cellar', turns 90 degrees, goes through the concrete foundation, turns 90 degrees down and enters a 4" pipe that is connected under ground to the city storm system.

It appears that the water is flowing away from the house once reaching the exit but the check valves are keeping the pipe filled and it is freezing at the top of the riser just below the 90 degree turn outside. Some say that you should drill a hole just above the check valve to allow this water to drain back into the pit (this would account for about 1/2 of the water from a pump out and would thus double my cycles). The check valves are required due to the double pump system.

Options I am considering:

1) About 1.5 feet from the top of the riser, installing a dishwasher coupling and having that top 1.5 feet drain back down into the pit via a plastic hose.

2) Install pipe heater wire on the top few feet of the discharge riser (but I have heard that if, for some reason, the pipe drains that the heater tape will fail because it needs the water to heat).

3) Drill a small, downward facing drain hole just above the check valve and allow the entire riser to drain out after each cycle.

4) Somehow try to 'insulate' the pipe outside of the house to keep the volume of cold air from coming in. The cellar stays in the high single digits most of the time and would not freeze although it is possible that the section at the top of the riser is subjected to external cold inside the pipe.

My pump only runs a handful of times a day in wet conditions and can be dry during other conditions. In the winter, it will typically be wet.

Any plumbers or plumbing experts able to suggest the best course of action? I have gone this far to ensure I never have a flood again but had not contemplated a frozen pipe basically negating the functionality of both pumps.

Thanks.

garys_2k
Premium
join:2004-05-07
Farmington, MI
I like option 1. Keeping the top of that discharge pipe empty is the best solution.


pende_tim
Premium
join:2004-01-04
Andover, NJ
kudos:1
reply to mepadre
Install a second independent discharge for the other pump?


hm

@videotron.ca
reply to mepadre
Can you post a picture of your set-up? Just want to take a look at it to see how high it rises relative to where the exit is and how close to the outside facing wall it is.

In regards to freezing, I was reading that there is a code (i'm not in construction thus don't know all the codes) that the pipe should be something like 3 inches in diameter (i forget the exact diameter would have to look at an inspection report I have) Using smaller diameter piping leads to this exact issue you are describing. Why? Dunno, but I have it written in black and white. So i'm curious about the size of piping you are using.

The pipe-warmers work good. Used those in industry. Wrap it around the outside of the pipe, plug it in. Nothing to do with water required to be in a pipe to work. Unless this is a diff product you are talking about. It's similar to those gutter heaters some people install outside on their roofs.

Also maybe you can install some sort of 60-degree elbow or similar pointed downwards outside to prevent cold air from blowing in?


AVD
Respice, Adspice, Prospice
Premium
join:2003-02-06
Onion, NJ
kudos:1
reply to mepadre
Look into #4.

A picture of the outside would be very helpful.

DBugman

join:2004-09-11
Kaukauna, WI
reply to mepadre
Definately agree that a picture would be useful.

Do you have an air gap between the transition from 2" pipe to 4" pipe or is it hard piped? Having an airgap will insure all the water is draining from the pipe as it goes into the sewer.


cdru
Go Colts
Premium,MVM
join:2003-05-14
Fort Wayne, IN
kudos:7
reply to mepadre
For the top of the riser to go outside, is that pitched at all to go outside? If not, it may be that water is accumulating at each pump, freezing, then repeating. And over time, eventually plugging. If it's not the vertical portion that's freezing pitching the horizontal section down may help.

Another idea is to go higher with the vertical pipe inside, put two 90s together to bring it back down and then out. This introduces more distance between where the water sits when the pump is not on and where the cold pipe is where water's freezing. Or instead of the two 90s, put a 90 then a 45 and angle it outside. You want to prevent any water from sitting for any period where it's freezing.


mepadre

join:2003-08-15
Waterloo, ON
reply to hm
Click for full size
I am attaching a photo that shows various angles.

Top Left - The pit showing the 2 pumps. Check valves are just after each pump.

Top right - An overall of the area. Pit is just next to the black box on the floor (this is the power for the backup pump). The riser is visible behind the 'sink' on the shelf. The top shelf in this photo above the 'sink' is the shelf that is visible in the next picture.

Bottom Left - The area that is freezing. I put a hairdryer on this exit for about 5 minutes and that frees things up.

Bottom right - The outside just immediately after the previous picture.

I gather some of my issue is the 'vent' right next to the pipe. I am going to close that in for the winter and insulate. Last night, the pipe froze again and the temperature in the room was approaching 0 C as measured by a thermometer on the power plug that is visible in the photo.

I am also considering whether plugging the 2 vents in the room plus leaving a 100W bulb on when really cold will produce enough heat during those really cold days to keep things warmer.

HarryH3
Premium
join:2005-02-21
kudos:3
I think that insulating the outside pipe will also help. It will help hold in some of the heat that the pipe/water absorbs from the inside.

Are the vents to provide combustion air for gas appliances???


mepadre

join:2003-08-15
Waterloo, ON
Agreed. I am going to pick up some Big-O end caps and some Roxul or comparable insulation to stuff in for the winter. Will also pick up a short run of pipe heating cable for this cold snap. Will also look at external insulation options but need to be conscious of the fact that this area is the front entrance to my house.

There are no gas appliances in this area. The vents are for air circulation and moisture which is a bigger issue in the summer. Obviously, vents in the winter are causing me issues and will be filled for the season.

I will find out whether insulating the vents and leaving on a 100w bulb holds temperature.


AVD
Respice, Adspice, Prospice
Premium
join:2003-02-06
Onion, NJ
kudos:1
wrap the pipe in a blanket then bury it under some sand.


hm

@videotron.ca
reply to mepadre
Yeah fill in that old vent asap. It likely is the source of the issue.

Dunno if a 100-watt bulb is worth it. I would go with the pipe cable. You only need a very short length of it. See:
»www.homedepot.ca/product/3-ft-el···e/909324
or
»www.homedepot.ca/product/6-ft-el···e/909325

Pennies to run.

Or just remove the check valve and adjust your floats on the pump for a higher water level. your pit look like it can accommodate that with no issue there. It will just raise the water level by maybe 4 inches or so.

Getting back to diameter. It sure does look like they are the same size. Going into and out the wall should be a minimum of 3 inches but I've been reading people use 4 to help prevent freezing as you are having.

For this winter, stuff that old vent with pink insulation or similar and spend the 25$ on the pipe heating cables or remove the check-valves. to solve the issue for the immediate.

I'm thinking in the long run, that if you remove the pipe from against the wall and run it straight up from the pit (against the shelving) and 3 inches higher than the exit, then run a pipe at an angle to the wall exit that this should add enough buffer to prevent freezing and keep it off the wall.

Yeah sure it won't be as pretty, but it will likely prevent this issue from occurring again since you indicate it occur at the exit at wall, only.

So my final answer would be that. If you don't want ugly, then stick with the pipe cable for ~25$ (get 6 feet minimum). Should be a lot less cost to run this than a 100W light bulb. Think this cable is only like 12-watts. Might cost you the same price as a coffee to operate for the season.

guppy_fish
Premium
join:2003-12-09
Lakeland, FL
kudos:3
reply to mepadre
If you insulate, I would think it would never freeze as there will always be a heat source from your basement. Insulate everything you can should cure your problem


cdru
Go Colts
Premium,MVM
join:2003-05-14
Fort Wayne, IN
kudos:7
reply to mepadre
said by mepadre:

I will find out whether insulating the vents and leaving on a 100w bulb holds temperature.

The heat tape is going to do the job better and consume less power than a 100w bulb. Plus it's going to have a thermostat on it so it's only going to kick on when it's needed.


hm

@videotron.ca
BTW, does anyone know what is the best way to insulate that old oil vent hole he has?


alkizmo

join:2007-06-25
Pierrefonds, QC
kudos:1
said by hm :

BTW, does anyone know what is the best way to insulate that old oil vent hole he has?

Id sprayfoam it shut.

HarryH3
Premium
join:2005-02-21
kudos:3
Reviews:
·Suddenlink
reply to hm
He can't remove the check valves. He has TWO pumps, a main pump and a backup pump. With no check valves in place then most of the water will just backfeed through the non-running pump right back into the pit.

telco_mtl

join:2012-01-06
reply to mepadre
just what ive seen when basement systems install sump pumps, at the exit of the house they put an air break in the system, so the pipe that exits the house discharges into a bigger pipe, keeps the outside pipe empty and lets air in the pipe.

seems to work


hm

@videotron.ca
reply to HarryH3
said by HarryH3:

He can't remove the check valves. He has TWO pumps, a main pump and a backup pump. With no check valves in place then most of the water will just backfeed through the non-running pump right back into the pit.

ah that's right. So we can scratch that one.


toby
Troy Mcclure

join:2001-11-13
Portland, OR
reply to mepadre
I had a similar problem with the drain for a humidifier that wasn't installed correctly. Instead of draining to the open air, I ran the pipe under the ground and insulated it, hasn't froze since.


cdru
Go Colts
Premium,MVM
join:2003-05-14
Fort Wayne, IN
kudos:7
reply to telco_mtl
said by telco_mtl:

just what ive seen when basement systems install sump pumps, at the exit of the house they put an air break in the system, so the pipe that exits the house discharges into a bigger pipe, keeps the outside pipe empty and lets air in the pipe.

That prevents the system from backing up when the discharge pipe freezes outside. It allows water to at least flow out of the house. The problem here though is that it's freezing just before it goes outside.

telco_mtl

join:2012-01-06
said by cdru:

said by telco_mtl:

just what ive seen when basement systems install sump pumps, at the exit of the house they put an air break in the system, so the pipe that exits the house discharges into a bigger pipe, keeps the outside pipe empty and lets air in the pipe.

That prevents the system from backing up when the discharge pipe freezes outside. It allows water to at least flow out of the house. The problem here though is that it's freezing just before it goes outside.

ever thought of putting one of those cheater valves on a stand pipe in the house, they allow air into the pipes and keep sewer gas out of the house for places you cant put a vent, but in this case put one of those cheater valves on the pipe inside the house, it will allow the pipe through the wall to empty between pump cycles


AVD
Respice, Adspice, Prospice
Premium
join:2003-02-06
Onion, NJ
kudos:1
from what I read, the pipe through the wall is empty, its the pipe on the inside that holds the water.
--
* seek help if having trouble coping
--Standard disclaimers apply.--


AVD
Respice, Adspice, Prospice
Premium
join:2003-02-06
Onion, NJ
kudos:1
if you really want to be clever, you can devise a siphon system.


cdru
Go Colts
Premium,MVM
join:2003-05-14
Fort Wayne, IN
kudos:7
reply to telco_mtl
said by telco_mtl:

ever thought of putting one of those cheater valves on a stand pipe in the house, they allow air into the pipes and keep sewer gas out of the house for places you cant put a vent, but in this case put one of those cheater valves on the pipe inside the house, it will allow the pipe through the wall to empty between pump cycles

You aren't understanding where it's freezing. The check valves at the pump ensure that any water pumped out doesn't drain back into the sump once the valve shuts off. That results in water standing in the pipe up to the top of the most vertical run of the drain pipe. After the pump shuts off, water is draining so that it's flush with the bottom of the horizontal run that heads through the wall. It's freezing right at this spot because either outside air is cooling through the pipe, or more likely the large vent directly beside where the pipe goes through the wall.

The water is not remaining at that level because of an air lock. An air admittance valve like you describe would not do anything. The solution to the problem is that either the air at that spot needs to be kept above freezing, or the water level in the drain needs to be lowered to a spot where the air temperature is above freezing. The latter can not (easily) be done with the check valves in place unless they are somehow bypassed, defeating some of their purpose of not having to re-pump water that's drained back into the sump.


mepadre

join:2003-08-15
Waterloo, ON
Thanks all for the input.

CDRU is bang on with where and how it is freezing... prior to my previous sump pump failure, I only had a single pump without a check valve. The stand pipe would drain back after each pump out and, effectively, double the number of pumps required to maintain the pit. That said, it also eliminated the freezing issue but increased the possiblity of an air lock on the pump.

I bought some Big-O end caps last night and stuffed the vents full of pink insulation before capping with the end caps. I do not want a permanent solution plugging the hole as they ventilate humidity in the summer. For those who aren't familiar with this type of setup, this 'room' is the area under the front concrete porch. It is separated for the basement proper by a steel insulated door and the room has no source of heating or cooling. Basically, it normally stays about 4C in the winter and about 12C in the summer. This has been an exceptionally cold winter but I want a solution that will be permanent.

When at the HoPo last night, I looked at the heater tape and spoke to one of the 'plumbers' at the HoPo (remember when Home Depot used to have knowledgable workers... it seems sometimes now it is whoever can fill out an application although some are still very good). The cables indicate they should not be used on drain pipe (supply only). I expect this is due to a fire hazard if the drain is empty and the heater is running? Comments? Someone with more knowledge than the 'plumber' at the HoPo?

Hoping a permanent solution is discovered before this cold snap stops and I have no way of testing whether anything is working


cdru
Go Colts
Premium,MVM
join:2003-05-14
Fort Wayne, IN
kudos:7
said by mepadre:

When at the HoPo last night, I looked at the heater tape and spoke to one of the 'plumbers' at the HoPo (remember when Home Depot used to have knowledgable workers... it seems sometimes now it is whoever can fill out an application although some are still very good). The cables indicate they should not be used on drain pipe (supply only). I expect this is due to a fire hazard if the drain is empty and the heater is running? Comments? Someone with more knowledge than the 'plumber' at the HoPo?

Some are designed only for metal supply lines. Others can work on drain. Freeze Free specifically mentions plastic drain pipes. It's only 3 watts per foot of cord with a 5' kit available in retail packaging.

Your application would be a little different then a typical drain application as your drain pipe usually would contain water. If indeed it runs a few times a day in winter, I doubt it will evaporate enough between pumps that it would run dry. Installing the heat tape a little below the 90 going outside would also provide additional time before it evaporated off, presuming convection currents in the water were enough to keep the top surface from freezing.

Another option is just to replace the plastic line with a metal one.


hm

@videotron.ca
reply to mepadre
said by mepadre:

The cables indicate they should not be used on drain pipe (supply only). I expect this is due to a fire hazard if the drain is empty and the heater is running? Comments? Someone with more knowledge than the 'plumber' at the HoPo?

From their webpage:
Warning: This cable has been designed for the sole purpose of preventing metal and rigid plastic water filled lines from freezing. DO NOT use this product on fuel lines, drain lines, hoses or buried pipes.

Guess that's right.

Another one to scratch from the list.

That leaves three options as far as I can see (if the insulation doesn't work).

1. Try your light bulb method.
2. Move the line away from the wall as stated above.
3. rig something to drain the top foot of water or so from the pipe.

telco_mtl

join:2012-01-06
reply to mepadre
Ahh ok, so basically its in your cold room, thats a different story, yup for now i think the only recourse is to block the fresh air holes for the winter and maybe put a light bulb in there for the duration of the cold spell as HM says


mattmag
Premium,ExMod 2000-03
join:2000-04-09
NW Illinois
kudos:3
reply to mepadre
You need to call the guy that designed a sump pit to be in the cold room and have him come keep it clear for you...