Water pump & water hammering

Jampy00

Jampy00

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Hey Gang,

Our basement is below the level of our septic system, so any water used has to be pumped up.
We have a pump in the bathroom for toilet, shower and sink and we have a larger pump for the water softener.
The issue I have (which many have for this or a sump pump) is when the larger pump finishes it cycle it "bangs" closed.
Not a issue with the pump but more like the water hammering when the valve closes. It happens only when the water softener recharges at 2am. From what I can tell this is a very common issue. Has anybody dealt with this and found a solution to quiet it down?
 
It could potentially be as simple as installing an inline water arrestor which prevents that bang.

Or a different spring in the pump.

I used to be in that business many years ago so don’t recall details. But I’d start with a water arrestor ($70-100) depending on size of line.
 
Jampy00 said:
Hey Gang,

Our basement is below the level of our septic system, so any water used has to be pumped up.
We have a pump in the bathroom for toilet, shower and sink and we have a larger pump for the water softener.
The issue I have (which many have for this or a sump pump) is when the larger pump finishes it cycle it "bangs" closed.
Not a issue with the pump but more like the water hammering when the valve closes. It happens only when the water softener recharges at 2am. From what I can tell this is a very common issue. Has anybody dealt with this and found a solution to quiet it down?
Click to expand...
My parents house has a sewage pump for the basement bathroom. Exact same issue. It has been that way for many decades and we've never tried to fix it. It's never caused an issue other than the noise. Given the infrequency that that pump runs and it only runs when at least one person is up, spending time and money on solving the hammer doesn't make sense.

In your case, with it happening daily and at an annoying time, I would be investigating a solution too. I suspect the answer is a different check valve that closes at a different speed/time to stop the hammer.
 
Install a water pressure shock absorber
You can make your own by installing a pipe that goes up from the feed pipe that is filled with air. The air cushions the "hammer".
They USED to put one in every system... just make sure it has some room around it to move, or you go from HAMMER to clanging pipes
 
bitzz said:
Install a water pressure shock absorber
You can make your own by installing a pipe that goes up from the feed pipe that is filled with air. The air cushions the "hammer".
They USED to put one in every system... just make sure it has some room around it to move, or you go from HAMMER to clanging pipes
Click to expand...
The problem with that is the discharge line is probably something like 1 1/2 or 2" pipe. A commercial 2" water arrestor is hundreds of dollars and I'm not sure the commonly available 1/2" ones have enough capacity. I am not sure about durability either with the brine coming out of the water softener.

You could make your own but if you don't install a piston, you need to top off the air chamber quite regularly (on the upside, you will hear when it's time so you don't need to check it often). It would be interesting to see if a homemade solution worked as without a piston, when pump is off, you are looking at maybe 7' of head (~3psi) and the hammer is normally well over 100 psi. Can you have sufficient volume to deal with that pressure ratio? On a normally pressurized system, the difference between high and low is much less most of the time (obviously, if you shut the water off, it can be the same). Can you buy a piston for a reasonable price? I have no idea as I've never tried.
 
Last edited:
Jampy00 said:
Hey Gang,

Our basement is below the level of our septic system, so any water used has to be pumped up.
We have a pump in the bathroom for toilet, shower and sink and we have a larger pump for the water softener.
The issue I have (which many have for this or a sump pump) is when the larger pump finishes it cycle it "bangs" closed.
Not an issue with the pump but more like the water hammering when the valve closes. It happens only when the water softener recharges at 2am. From what I can tell this is a very common issue. Has anybody dealt with this and found a solution to quiet it down?
Click to expand...
As I read this it appears your banging is on the low pressure side, that’s likely a check valve slamming shut.

Fix is easy. The water softener shoud not be routed to a septic drain line, a softeners discharge is evacuated under pressure it doesn’t need a pump. The drain line should run up from the softener then directly to the outside ( not into your septic. )

If you must dump to the septic (not a good idea for water softeners), eliminate the pump and route discharge line into the horizontal drain line exiting the house.

Quiet. More efficient. Eliminates some damage risk associated with power a pump failure.
 
Mad Mike said:
As I read this it appears your banging is on the low pressure side, that’s likely a check valve slamming shut.

Fix is easy. The water softener shoud not be routed to a septic drain line, a softeners discharge is evacuated under pressure it doesn’t need a pump. The drain line should run up from the softener then directly to the outside ( not into your septic. )

If you must dump to the septic (not a good idea for water softeners), eliminate the pump and route discharge line into the horizontal drain line exiting the house.

Quiet. More efficient. Eliminates some damage risk associated with power a pump failure.
Click to expand...
My parents water softener works this way. Separate drain line through the floor and then away from the house and not into the septic. In an existing situation, installing that floor drain (and sloped piping to a discharge at a lower elevation) would be crazy expensive.

How does softener discharge under pressure? Uses a jet of water to siphon the tank? They all discharge under pressure or just some? I've fixed my parents before and I don't remember seeing a pump, just some valves and solenoids.
 
GreyGhost said:
My parents water softener works this way. Separate drain line through the floor and then away from the house and not into the septic. In an existing situation, installing that floor drain (and sloped piping to a discharge at a lower elevation) would be crazy expensive.

How does softener discharge under pressure? Uses a jet of water to siphon the tank? They all discharge under pressure or just some? I've fixed my parents before and I don't remember seeing a pump, just some valves and solenoids.
Click to expand...
Discharge (on the last one I owned) was using supply side pressure. A solenoid opens to backwash the treatment canister

Backwash process is the same as a pool pump.

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Mad Mike said:
As I read this it appears your banging is on the low pressure side, that’s likely a check valve slamming shut.

Fix is easy. The water softener shoud not be routed to a septic drain line, a softeners discharge is evacuated under pressure it doesn’t need a pump. The drain line should run up from the softener then directly to the outside ( not into your septic. )

If you must dump to the septic (not a good idea for water softeners), eliminate the pump and route discharge line into the horizontal drain line exiting the house.

Quiet. More efficient. Eliminates some damage risk associated with power a pump failure.
Click to expand...
Yes, I have read this also. Where the softener is located is the most likely reason it dumps into the septic system. I've been considering one of those salt free systems so no more need for recharges, but not sure if it will work with my well water.
 
My one experience was a condo on Lawton Blvd and an extreme lot development that went the wrong way. The lot shape dictated that the building was below street sewer elevations and the sewage had to be pumped up to the street. It seems someone tried to confuse the plumber who only knew payday was Friday and crap flowed downhill.

Complicating the issue was the assumption they had that they could build a fairly tall building with lots of suites. I heard it abutted the TTC subway line and they objected, citing concerns about retaining walls collapsing under loads with the building possibly sliding onto the tracks.

IIRC there was a financial failure and somewhere in the process a plumber, not knowing that in some cases crap could flow up hill, used standard couplings instead of ones for force mains.

Vacancy was low for a while but as vacancy grew unpleasant smells were noticed in the elevator. A coupling had failed and the elevator shaft became the septic tank.

The failure was under a very long heated ramp which had to be torn up. Cheap couplings can be very expensive.
 
Update.
Replaced original check valve with one from pumpspy (bought from Amazon)
No more banging, in fact all you here is a slight hum from the drainage pump when working.
I can't believe the difference !
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