Plumbing for an Ice Machine Drain

Hello. My church recently purchased an air-cooled under-the-counter Manitowoc ice machine. In the cabinet slot where it is going to be installed (on the far end of the kitchen with its back against an exterior wall consisting of sheet rock/insulation/metal siding), we do have a water hookup available but do not have any drain to accommodate the gravity drain on the back of the machine (for ice melting in the storage bin).

We have thought about just piping a drain out the wall to the exterior of the church since it would be on the back side of the building. However, I don't really know the best way to do that. We would also like it to be where we could slide the machine out from the wall if needed for maintenance, etc. Also, we don't want bugs or other creatures getting in through the pipe. Is an air gap needed in the drainage? Any advice would be appreciated. Thank you.

An air gap is required. Most under counter ice machines do not produce much ice. What will you be using it for? You might be able to put in a condensate pump but I would avoid that if possible. An indirect drain with a p-trap would prevent bugs from crawling inside.

Thanks for your response.
It will make 190 lbs per 24 hrs and store ~90 lbs. We will basically use it for all of our functions in and around the church (meals, fundraisers, any and all events really).
We are out in rural MS, so we are not subject to code inspections or anything like that. Nevertheless, I would obviously like to do this so as to avoid future problems and ensure the safety of those using the ice it makes.

You are not subjected to inspections? Really? And you want to install a machine that makes ice that the general public will be using? Without a health and safety inspection? BTW you pipe it outside and the line freezes in the winter, backing the water up and contaminating the ice. Any idea how fast bacteria grows in an ice machine? Oy vay hire a plumber.

Tom Sawyer said:

You are not subjected to inspections? Really? And you want to install a machine that makes ice that the general public will be using? Without a health and safety inspection? BTW you pipe it outside and the line freezes in the winter, backing the water up and contaminating the ice. Any idea how fast bacteria grows in an ice machine? Oy vay hire a plumber.

Click to expand...

The probability of it getting cold enough in South MS to freeze an exterior flow is low. Nevertheless, even if it did freeze and water backed up, the air gap inside would prevent such an event from directly contaminating the ice machine and accelerating the proliferation of bacteria. In that event, we might have some mopping to do, but I doubt we would endanger lives as you suggest.

How far above the floor is the drain fitting, which way is it pointed, is it a barb or threaded, and how far is it from floor level inside the building down to ground level on the outside?

Something as simple as an air stone for an aquarium could keep bugs from crawling in through a tube in the wall, so the biggest challenge you have is figuring out a way to be able to slide the unit into place and/or out again without having to struggle with the drain connection.

Thanks for your response.

leejosepho said:

How far above the floor is the drain fitting

Click to expand...

Approx. 8"-9"

leejosepho said:

which way is it pointed

Click to expand...

It is pointed out the back of the machine.

leejosepho said:

is it a barb or threaded

Click to expand...

There is a threaded opening (1/2" female pipe threads)

leejosepho said:

how far is it from floor level inside the building down to ground level on the outside

Click to expand...

I would estimate 1' or so.

leejosepho said:

Something as simple as an air stone for an aquarium could keep bugs from crawling in through a tube in the wall, so the biggest challenge you have is figuring out a way to be able to slide the unit into place and/or out again without having to struggle with the drain connection.

Click to expand...

I was hoping to do something like the following if plausible:

1: Come out of ice machine and turn vertically down towards the floor (put a valve here so drainage line could be shut off if machine were to be pulled away from wall for maintenance/repair/cleaning)
2: Air gap approx. 2x the diameter of the pipe
3: Horizontal catch pipe (with P-trap) that runs through the wall to the exterior of the building
4: Once outside, turn pipe vertically down into buried 5 gallon bucket (bucket is 1/2 full with pea gravel and 6-8" pea gravel underneath).

This would prevent anything from getting through drainage pipe, would allow machine to be removed as it would not be rigidly plumbed in place, and would prevent any backups directly into the machine to avoid contamination of the ice/storage bin.

As someone who has owned restaurants, I just want to make a slightly-different point.

Ice machines are a surprisingly-common source of people getting foodborne illness, in part because what they produce is delivered to the customer without being heated.

So, if you're going to use this commercial product, do yourself a favor and get a copy of its use and care manual online at the Manitowoc web site or by calling Manitowoc customer service. Then be religious (no pun intended) about following the cleaning instructions by the manufacturer to the letter. Every step is important. The proper nickel-safe cleaner and/or sanitizer are available online and in most restaurant supply places. So many restaurants fail health inspections when the inspector decides to take his mirror and flashlight and actually look inside the thing, because a surprising number of people in the business don't have it in their mind that gross green nastiness forms inside and contaminates the ice, and therefore don't do anything to prevent it.

Moreover, when you install the thing, you usually install a water filter in the line to the machine. Manitowoc makes one, but so do several other manufacturers. The easiest ones to use are the ones with a filter cartridge that you just use a quarter-turn to remove and swap with the new one. You change them every six months or so.

In a hot moist environment like where you are, the stuff is going to grow more readily than in some other areas.

Here's a video of how to clean a machine, although it doesn't sound like it's your model. Still, many of the concepts are the same. Those plastic pieces can get pretty nasty; funny to see how pristine they are in the video.

[video=youtube;T3sI8rGDiJI]http://www.youtube.com/watch?v=T3sI8rGDiJI[/video]

squidbilly said:

4: Once outside, turn pipe vertically down into buried 5 gallon bucket (bucket is 1/2 full with pea gravel and 6-8" pea gravel underneath).

Click to expand...

Squidbilly, everything sounds good up to number 4 above. I don't think the bucket will be necessary. I would just terminate the pipe a few inches after it goes out and you elbow it down and just let it drip out. For some reason slime does form in the drain pipe as wjc says and it may clog up the gravel. Getting the bucket out after you fill it with gravel and extend the drain into it is going to be difficult. I think the p-trap is all the barrier you will need. You could put a little rabbit wire over it if needed.

You never put valves in drain lines

There is usually adequate space in the bottom of the machine's cabinet to install a condensate pump. Do not use one with a "small" bucket.

I have attached a simple schematic of what I had in mind. I also purchased an Everpure (EV910010) water filtration system. Does anything need to be changed? Thanks.

That looks good.

hj said:

There is usually adequate space in the bottom of the machine's cabinet to install a condensate pump. Do not use one with a "small" bucket.

Click to expand...

What do the installation instructions say about condensation, SquidBilly? I can imagine a built-in drip pan for evaporation. Is the building air-conditioned?

leejosepho said:

What do the installation instructions say about condensation, SquidBilly? I can imagine a built-in drip pan for evaporation. Is the building air-conditioned?

Click to expand...

"Insulate water inlet lines to prevent condensation." That is all the installation manual says about the topic. Yes, the building has A/C.

I had thought about adding a vertical pipe just before the drain pipe enters the interior wall to make it easier to pour liquid down (Chlorox) to keep the drain open.