Question about Watts Premier Watts 9D-M3 1/2 1/2 Backflow Preventer

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Vent pipe connection to Watts 9D-M3 BackFlow Preventer

How do I connect vent opening of the Watts 9D-M3 Back Flow Preventer. The vent opening is not threaded, so I assume it has to be soldered. My concern in soldering that the internal rubber seats may be damaged by the heat. Do I remove the internal mechanism to prevent damage to the seats? Or is there another safe way to do this?

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Every Watts 9-D I have installed had a 1/2" female thread as the vent opening. I think yours is defective. If you have already installed your 9-D, just take it apart at the unions and return the body for a refund. If they complain that the union nuts are missing, have them take the nuts off of the replacement. Good luck!

Posted on Jan 18, 2014


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Posted on Jan 02, 2017


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How do you install replacement Watts Watts Nf8 backflow preventer

It screws onto the hose bib before the hose is connected. Its ez ...unless there was one on before. If that is the case you will need to remove the set screw on the old one (drill it out). unscrew it and attach the new one, tighten the set screw until it breaks off and you are done!

My answers are short and sweet. Common sense mostly. If you are trying to get something for nothing...Don't waste my time! Remember if something sounds to good to be true that it usually is. I've spent many years of my life trying to cheat the system and was pretty good at it. This all changed when I discovered that people were doing the same thing to me. What comes around, goes around. Karma! Now I assist people in making win-win deals...that are legit!

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Rheem 22v50f1

Backflow preventer is not part of water heater:

Water heater might have heat trap nipples that get clogged... but other issues have to be eliminated:

Gene h

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High pressure due to back flow preventer

Add a variable regulator to the house side of the check valve. Also add a pressure tank between the regulator and the hot water heater.

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Watts backflow prevention device 009M2 relief valve spraying continuously

As a Backflow Tester, I have to recommend calling a certified Tester with experience in repairs. There are a few thing that could cause this such as debris stuck on the #1 Check disc (which usually means repair parts) or a nick on the Relief Valve seat. The rv seat is stainless steel and just pops in the bottom of the valve with an o-ring seal but unless you have experience at this I suggest you leave it to a professional as you could easily damage other parts or reassemble improperly.

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E4 code on a bosch ghw 715 control unit

Before calling service technician, open following link for Bosch troubleshooting resources:

Error codes are starting point for troubleshooting, and solutions vary by model and unit.
E4 is Backflow temperature sensor over 309 degrees F. Appliance will close burner and lock.
Check combustion air and backflow vent piping for blockage.
Check if secondary fan connections are disconnected.
Check venting specifications are met. Long vent lengths, venting with more than three elbows, blocked vent or combination venting may cause this failure.
Check sensor resistance

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1 Answer

We have a saniflo and when we flush the toilet the pump does not switch off we are having to switch off at the main switch any idea's?

the connection between pump and outflow pipe is cracked under the elbow/backflow preventer has a rubber connection take backflow elbow out clean the rubber under it if ther is a crack in it the water keeps cycling back in tank so it thinks it is always full

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My Saniflo toilet has just started to pump/grind every half an hour of its own accord, I have had to switch it off as I am worried it will cause more damage.

sounds like the backflo preventer is bad letting water back down from system the backflo is the fitting is in the elbow fitting on top get a bucket when you loosen connection water from pipe will flow out then take elbow out of tank the backflow is the valve in bottom of the elbow it has a twist lock take out and clean if its cracked or any reason will not stay closed replace it

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When draining water out of the sink, it backflows into the dishwasher. Doesn't the dishwasher have a backflow preventer valve where the drain tube connects to it?

Actually no they do not have a back flow preventer, make sure the dishwasher drain connection is installed on top of the "P" trap, if it is then you are having drain problems , remove and clean the "P" trap if it not clodded then you need your pipes cleaned out if it is backing up in dishwasher.. Do it sooner than later or may become totally stopped up..

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1 Answer


The dishwasher drain line that connects to the garbage disposal or pipe under the sink should be looped above the height of disposal or pipe to prevent
sink water from backflowing into dishwasher.

Most dishwashers have some form of internal backflow preventer inside the water sump assy..
Yours may be degraded or stuck open.

Jan 16, 2010 | Dishwashers

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