Hope I’m not about to get a call back…
We recently finished out a basement that included a half bath. We went with a Saniflo Plus. When reading the installation destructions, I noticed that they specifically said not to use an AAV, although for European installations they seemed to say that you could plug the vent entirely, leaving only a tiny opening. I spoke to two plumber friends that called BS, and said that a good AAV was fine. Coincidentally, one of these guys just installed the same thing for a buddy of mine, although the fixtures aren’t placed yet, and he used an AAV…
We finished the install and found that with the AAV in place, the toilet drains fairly slowly, with the pump running for about 5 seconds per flush. With the vent pipe opened, it flushes instantly and the pump runs just a second or two. In the very very poor instructions, they seem to imply that the pump needs a certain minimum run time (presumably to macerate the ummmm… contents adequately).
Anyone else install one of these? Should I be sitting by the phone waiting for a callback?
PaulB
Replies
I have installed one. I ran 1" pvc off the vent opening and dropped it in the top side of a horizonal 3" drain line. This makes a kind of loop vent.
The chamber where the pump is needs air to flow out when the toilet is flushed, when the pump kicks on air must flow back in for proper operation of the pump.
An AAV only allows air to flow in.
Gulp... I wish someone would have thought of that earlier. Makes perfect sense. Now I just have to figger out a way to do that, and wait for what seems like the inevitable phone call. I wonder if I oughta call me buddy who just had one installed or the plumber that did the install and give him the news...PaulB
Yes a tank and pump needs bi-directional venting.Out when filling and in when pumping.However saniflow makes one that they says does not need to be vented. Don't know how they do it. I can see some system of using a checkvalve and solenoid valves to allow the discharge line to be the vent during filling and a builtin AAV to handle the air in when pump.Or I wonder if they could use a carbon filter for the air out. That would require periodic replacement..
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A-holes. Hey every group has to have one. And I have been elected to be the one. I should make that my tagline.
I think that is wrong what I said about some that done need venting. There are some installations that don't."Important Installation Notes
Venting for Macerating Systems
As per plumbing code all P-traps need to be vented. Therefore, even though macerating systems are isolated from the main drain system (by means of a check valve), the trap of the hand basin, shower, bathtub or bidet must be vented. The following external macerating systems MUST be vented: Saniplus, Sanipack, Sanibest and Sanigrind. Systems with built-in motors, such as Sanicompact and Sanistar need not to be vented (they are considered to be a forced main).External macerating systems have a tapping on the lid, generally located on the right hand side and are 1½-inch diameter. To start one needs to saw off the cap and connect the provided 1½-inch accordion connector to it. Then a street-elbow can be pushed into the other side of the accordion connector and one can finish off the vent installation in 1½-inch pipe.Vent pipes MUST slope upwards (¼-inch per foot) when running in the horizontal plane. If one cannot get at the house’s vent system, the vent pipe may run along the joists to the outside of the house. Do NOT use air admittance valve (also known as cheater vents) because these are one-way devices. Macerating systems need a two-way air movement, OUT when the toilet is flushing, i.e. water is running into the pump case, and IN when the macerating unit is pumping water out of the case.Note: When connecting to a vent system, please push the provided plastic cap into the breather opening located on the left hand side of the lid. Otherwise there exists the possibility for odor (not sewer gas but odor).".
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A-holes. Hey every group has to have one. And I have been elected to be the one. I should make that my tagline.
or the plumber that did the install and give him the news...
Yup, & if he's a "plumber" he should have known better.
saniflo plus venting info
I've installed a lot of Saniflo products and most of them require an 1.5" vent pipe, vented to the open air. They do not recommend using AAV's or any type of mechanical vents as they only allow air to flow one way. Air must constantly flow in and out of the vent pipe so the unit can work properly.
Venting Sanibest
I'm wondering if it's only the macerating pump that needs two way airflow. Would adding aav's on the fixtures themselves (sink, shower) and venting the pump/toilet directly work? Or are aavs not allowed in the entire system?
I suspect that the problem is that a AAV only allows air in, and if pressure develops there's no way for it to escape (other than to bubble up through the traps). The one-way flow is OK for what an AAV is intended for, which is break the vacuum that develops from a slug of water flowing through a drain, but overall the plumbing system must be able to let pressure out, since pressure will develop as things warm up, and since, especially in a macerator pit or other tank-like structure, yeasty beasties will put out CO2, et al.
Paul did you ever fix your saniflo vent issue?