How to self Drain the Basement Pipe

If you were not home or you want to drain the sprinkler system's pipe prior to our arrival, please follow the instructions below very carefully. Please note that if you skip any steps in the process your sprinkler system might have damage the following spring.




Step #1 - Go downstairs or to the crawlspace or basement and find the sprinkler shutoff valve. This valve could be a lever (ball valve- Illustration B) or a thing to twist like your outside spigot (gate valve- Illustration C).

If it is a lever (Ball Valve) turn it until the lever is perpendicular with the pipe. With ball valves perpendicular to the pipe always means the valve is closed and parallel with the pipe always means the valve is open.

If the valve is a gate valve (C) please turn it clockwise to close the valve. If you have a gate valve (C) you need to turn it has hard as possible because they can often leak water if they are not completely closed.

Please note that there may be many pipes in the basement and this can be a little confusing. If you are not sure where your sprinkler shutoff valve is located you should first find the backflow preventer (pipe structure outside the house shown below –Illustration A) and trace the pipe backwards until you reach the first valve. This is your sprinkler shutoff valve.

Ball Valve

This is a ball valve. This is what a basement pipe sprinkler system shutoff often looks like.

Gate Valve

This is a gate valve. To close this you need to turn the handle area all the way clockwise until it stops moving. Then you need to turn it very hard to make sure it is 100% closed.


Step #2 - Make sure that you have turned off the sprinkler shutoff valve and not another water valve. You should turn the water on at your kitchen sink and the sink water should still be flowing; if the sink water is not flowing, you have shut off the main water to the entire house. If you have shut off the water to the entire house, go back and turn off a different lever until you turn off the correct lever. After you turn off the correct lever, mark it "sprinkler shutoff" so the following year you know exactly what lever will shut off the sprinklers.

Now that the sprinkler water is off, you need to go outside and find the backflow preventer, which is pictured to the right (this can be in the front, back, or either side of the house).



Step #3, (Turning off the water and draining the pipe if the sprinkler system has already been blown out)

If we have already blown out the system, one of the valves on the Backflow Preventer will be at a 90 degree angle (perpendicular or shut). The other valve will be left at a 45 degree angle.

Only after you have turned off the water should you turn the other valve to a 45 degree angle. Lever #2 will be on the pipe coming out of the house. Turning the valve at a 45 degree angle will allow airflow into the basement pipe.

Note: If water gushes out of the testcocks then you have not shutoff the correct valve in the basement. If water is gushing out from the petcocks, close the valve back to a 90 degree angle (closed) until the water stops and please contact our office. We will need to blow out the system again because water probably got into the back flow preventer.



Backflow preventer

Step #3, (Turning off the water and draining the pipe before the system has been blown out)

If you are draining the water prior to our arrival then the lever will be parallel (open) with the pipe. You can either leave this lever open or you can put it to a 45 degree angle, but do not shut it or put it at a 90 degree angle. Leaving it open or at a 45 degree angle allows air to flow properly and therefore allow the water to drain.

When you arrive the testcocks will be closed or perpendicular when you arrive. You need to open both of the testcocks by using a flathead screwdriver to turn the screw on the side of the testcock to so it is parallel with the petcock. If you are not sure how to do this just turn the screw 1/4 of a turn. It is important to open the petcocks because if they are closed no water will drain from the basement because there will not be any airflow in the pipes. Continue to Step #4.

Note: A little water will gush out of the testcock and then stop, this is normal. If it continues to gush then you have not shutoff the correct valve in the basement. If water is gushing out from the petcocks, close the testcocks back to a 90 degree angle (closed) until the water stops and go back downstairs and try to find the correct sprinkler shutoff valve.



Sprinkler Test Cock

Step #4 - Go back downstairs to the sprinkler shutoff valve. Take a bucket with you so you don’t make a mess with the water. Between the sprinkler shutoff valve and the backflow preventer there should be a water drain nipple. This usually is a small nipple (see arrow to the right) or occasionally a spigot drain just like your outside hose spigot. After you find the drain put the bucket up to the drain nipple or spigot and unscrew the nipple or open the spigot and drain the water. Do this until all the water is completely drained from the pipe. If no water drains please see the note below. If the pipe drains you are finished.

Note: If no water comes out of the pipe this means you have a vacuum lock because there is no airflow in the pipe. You have either not opened the lever #2 to a 45 degree angle or the petcocks are closed. Close the water drain and go back to the backflow preventer and open either lever #2 or the petcocks and try again. If this does not work please contact our office for advice.



Drain Nipple

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