Frozen sump-pump discharge line
#1
Member
Thread Starter

Hi Friends,
So in winter (when we have freezing temperature & snow) my sump-pump discharge pipe does freeze, and blocks the water going through it when the sump-pump starts.
I want to prevent the line from freezing in winter.
Please review the 3 pictures I have attached herewith.
The discharge pipe is about 1.5" PVC pipe.
I think the slope is good too - in favour of gravity. The pipe goes away to the back yard for about 10 feet or so, nothing underground.
Since this happens outside, I think electric tape/heat-wrap/insulation, etc. solutions won't work.
I am even Not sure exactly what point it gets icy.
I believe it's the end point where it meets the ground or could it be anywhere? Please see images where I marked points and questions.
I'd definitely want to fix this in this summer, before cold weather starts.
Please share your thoughts and help me fix this permanently.
Thank you in advance for your time.
Best,
SP_DIY
So in winter (when we have freezing temperature & snow) my sump-pump discharge pipe does freeze, and blocks the water going through it when the sump-pump starts.
I want to prevent the line from freezing in winter.
Please review the 3 pictures I have attached herewith.
The discharge pipe is about 1.5" PVC pipe.
I think the slope is good too - in favour of gravity. The pipe goes away to the back yard for about 10 feet or so, nothing underground.
Since this happens outside, I think electric tape/heat-wrap/insulation, etc. solutions won't work.
I am even Not sure exactly what point it gets icy.
I believe it's the end point where it meets the ground or could it be anywhere? Please see images where I marked points and questions.
I'd definitely want to fix this in this summer, before cold weather starts.
Please share your thoughts and help me fix this permanently.
Thank you in advance for your time.
Best,
SP_DIY
#2
Group Moderator
Where are you located?
Your pipe is outside so of course freezing is a concern.
Your pipe runs a very long distance unsupported. It's possible it sags under the weight of water and ice so you get a low spot that accumulates water which then freezes. Try supporting it better and maintain a good downhill slope. If the water can drain quickly without accumulating most of it may get out of the pipe before it can freeze. What thin film of ice that does form can be melted away by the water the next time the sump pump cycles on.
The best solution would be to have it exit the house below the frost line and run the pipe downhill to daylight. If you want to stay with it being exposed then you may just have to fight the ice. Insulation and heat tape will work by melting the ice that does accumulate but it requires electricity and a bit of work to maintain it and make sure it works outside.
Your pipe is outside so of course freezing is a concern.
Your pipe runs a very long distance unsupported. It's possible it sags under the weight of water and ice so you get a low spot that accumulates water which then freezes. Try supporting it better and maintain a good downhill slope. If the water can drain quickly without accumulating most of it may get out of the pipe before it can freeze. What thin film of ice that does form can be melted away by the water the next time the sump pump cycles on.
The best solution would be to have it exit the house below the frost line and run the pipe downhill to daylight. If you want to stay with it being exposed then you may just have to fight the ice. Insulation and heat tape will work by melting the ice that does accumulate but it requires electricity and a bit of work to maintain it and make sure it works outside.
#3
Member
Thread Starter
Thank you "Pilot Dane" for the quick reply.
I'm in Philadelphia suburb.
I'll try to support the long running pipe in between while maintaining appropriate downhill slope.
Any other sure way to prevent this?
I found this: "If it's frozen, disconnect the flex (outside) and slip a piece of 3" or 4" pvc pipe (10' or longer) keeping little air space over the 1-1/2" pipe coming out from the house to run the water away from the foundation."
But my question is can it get frozen at the starting point (See the last image)?
I'm in Philadelphia suburb.
I'll try to support the long running pipe in between while maintaining appropriate downhill slope.
Any other sure way to prevent this?
I found this: "If it's frozen, disconnect the flex (outside) and slip a piece of 3" or 4" pvc pipe (10' or longer) keeping little air space over the 1-1/2" pipe coming out from the house to run the water away from the foundation."
But my question is can it get frozen at the starting point (See the last image)?
#4
Yes..... IF you have a check valve between there and the pump. The check valve will keep the line full of water from right above the valve to that fitting thru the wall.
The check valve keeps excessive water from draining out of the drain line back into the pit.
I think I'd make two changes..... remove the check valve and add a stub of 2" PVC and a 1-1/2"-2" adapter/coupler. The 1-1/2" PVC would drain into the 2" allowing air in and the water to drain out.
The check valve keeps excessive water from draining out of the drain line back into the pit.
I think I'd make two changes..... remove the check valve and add a stub of 2" PVC and a 1-1/2"-2" adapter/coupler. The 1-1/2" PVC would drain into the 2" allowing air in and the water to drain out.

#5
Member
Thread Starter
Thanks PJmax.
You mentioned about removing the check valve.
Can I just do the 2nd change (adding a 2" or larger stub) you suggested and fix the problem?
Also a side question: Do I have to cut the pipe or is there any neat way to release the arm connectors in the line? Thanks...
You mentioned about removing the check valve.
- Won't it make my pump do more work?
- Also in case of heavy rain fall, will the pump keep it up as it now has to pump more water out?
- Will it cause basement flooding as the pump won't be able to keep up?
Can I just do the 2nd change (adding a 2" or larger stub) you suggested and fix the problem?
Also a side question: Do I have to cut the pipe or is there any neat way to release the arm connectors in the line? Thanks...

#6
Your fittings appear to be glued on to the pipe..... so they are not removable.
Without the check valve you will only get the water back that is in the line in the basement. That might amount to a 1/2 gallon. The check valve does not control the pumping.
Without the check valve you will only get the water back that is in the line in the basement. That might amount to a 1/2 gallon. The check valve does not control the pumping.
#7
With the air gap idea being discussed, wouldn't there be the potential for water to come squirting out of the gap? He's got that long gentle slope, and with the pipe being open the pump can no longer force the water down that long slope, so you're at the mercy of how fast the water wants to mosey out of there. I guess it depends on how fast the sump pump shoots the water out.
I still think it's a good idea; just thinking aloud.
I still think it's a good idea; just thinking aloud.
#8
Group Moderator
I think simply removing the check valve will solve the problem. If you try the short section of 2" at the top and you do end up having water squirting out then it's simple to just replace the entire outside section with 2".