Build A DIY RIMS System

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I recently had a chance to brew with the professionals at a local brewery. They were brewing on a SABCO Brew-Magic (15 gallon) system that they use for their weekly small batch releases. The brewer explained the components and how they all worked together. The wort would circulate throughout the mash process and that the temperature would be kept constant by an electric heater that was in the circulation loop. And, the re-circulation helped with the efficiency and the clarity of the wort. The price tag for a system like this is way out of my price range, so buying one was not an option. It didn’t take long for me to start putting ideas together to build my own RIMS. My quest began to put something together that I could build cheaply and maybe upgrade over time. So, a low cost system (that was modular) is what I set out to build.
Editor's Note: Hello everyone, this article was previously released and the author had used PVC piping for some of the heated elements of the system. After a lot of feedback on the issue, I made the decision to take the article down after potential safety issues were raised. I spoke with the writer and he agreed to upgrade the system he had originally built to use SS parts and re-write the article for the new build. So thank you to you the readers who spotted an issue, and a big thank you to Ted for upgrading and re-writing which took a lot of work.
There is already a bunch of nice, well thought out, designs out on the web. But, many were not cheap to build. The biggest expense was going to be the pump. I lucked out, I already had a 1200 GPH pump that I bought for a Koi pond and it wasn’t being used anymore. Yes, I cleaned the crap out of it, literally. Next, all those stainless steel pipes and fittings were $10-15+ each, times 10 or more. It was adding up fast. I originally chose PVC for a bunch of the parts. It was cheap, but after a lot of push back from reviewers about PVC temperature ratings, I replaced the PVC parts for the heat chamber with stainless steel parts. This increased the cost about $65. So, if you had to buy everything and did your shopping around, everything should cost under $350.
To clean the RIMS, I get a few gallons of PBW solution in a bottling bucket and connect it to the pump input and just pump it through the system and back up to the bucket. I let it run for about 20 minutes to a half hour. I’ll switch out the PBW with some sanitized to get it squeaky clean. The system works great. Nice clean beer and my efficiency is up about 5%.

Safety First

This system is being used around water and hot wort. Accidents can and will happen. Don’t shortcut the safety of the electrical. If you don’t know how to do this, let some who does take care of the electrical work or save up and buy one.
Modular design
I wanted to make my setup modular and compact. Something I could build into a portable carry case.
Use the temperature controller for more than just controlling re-circulation temperatures.
Use the pump for more than just re-circulation during mashing.
Project and electrical boxes for containing, controlling and switching things.
I set up my temperature controller with multiple switches to turn on and off the pump and heater. The power outputs from the controller box are wired to a standard A/C outlet within the covered box. So, the pump goes into the pump outlet and the heater goes into a heater outlet. I accomplished by breaking the hot power contact on the outlet and wiring them separately from the project box. Then, the switches will control whatever is plugged in to the outlets. This helps to keep the equipment modular. Now, I can plug in a heat wrap and control the temperature in a fermenter or pump water and moving wort between pots and to the fermenter using the switches on the project box.

I went with hose clamp connections between the heating element and the pump (not in the pictures), so they can be disconnected fairly easily. These will eventually be upgraded with some quick disconnects to make it even faster.
I did not want to hard connect the temperature sensor to the heating chamber or the load on the heating element. By setting it up this way, I am able to plug in whatever load I wanted and mover the temperature probe to wherever I needed it. For example, I can use the temperature controller for my heater wrap to control fermenter temperatures or just move the probe to measure temperature of grain, cooling wort, liquid in a hot liquor tank, etc.
The liquid from the mash tun will come down into the pump on the right. The flow can be controlled with the valve before it enters the heating chamber on the left, where it is heated and forced back up to the mash tun.

Parts List

  • 1 Hose Fitting, Adapter, 3/4" NPT Male x 1/2" Barbed
  • 1 Ball Valve Full Port 304 Stainless Steel w/Blue Vinyl Handle 2PC 2-PC
  • 3 AC 110-120V 3 Pin I/O Control SPST Rocker Switch
  • 2 Hose Fitting, Adapter, 1/2" NPT Male x 3/8" Barbed
  • 1 White Silicone Tubing, 3/8"ID, 1/2"OD, 1/16" Wall, 10' Length (I’d recommend using ½ inch ID to go back to the tun, it won’t kink as easily.)
  • 1 5500W 240V Screw-In Foldback Water Heater Element - High Watt Density
  • 1 2-1/2" Thermowell Stainless Steel 304 - 1/2" Male x 1/2" Female
  • 1 Hammond 1591ESBK ABS Project Box Black
  • 1 Inkbird All-Purpose Digital Temperature Controller Thermostat w Sensor 2 Relays1 1/4"
  • 1 1 1/4" X 8" Stainless Steel Pipe
  • 2 1 1/4" Stainless Steel T
  • 3 1 1/4" X 1/2" Stainless bushing
  • 1 1 1/4" X 1" Stainless bushing
  • 1 2 gang outdoor outlet box for GFI
  • 1 GFI outlet
  • 1 Standard Outlet
  • 2 Outdoor A/C extension cords

Basic Build Steps

1. Build a Base

I built a base out of some scrap wood. It is basically an “L” shape, with parts connected to it for stability and transport, and a box to hold pump. The dimensions will probably be different for yours, depending on size of the pump. My base dimensions: 18” long x 8” high x 7” deep

2. Build the Heat Chamber and Connect the Pump

2a. Upper Tee Assembly:
Assembled the following parts using Teflon tape to complete the upper tee assembly.
  • 1 1/4” Stainless Tee
  • 1 1/4”x 8” Pipe
2b. Hose End Adapters:
  • 1 1/4" Male X 1/2" adapter
  • Hose Fitting Adapter, 1/2" NPT - Male x 1/2" Barbed
2c. Temp Sensor and Adapters:
  • 1 1/4" Male X 1/2" adapter
  • 2-1/2" Thermowell SS - 1/2" - Male x 1/2" Female
2d. Lower Tee Assembly
The heating element will thread through the outlet cover and into the 1" reducer in the Tee. Use Teflon tape or pipe joint compound to seal it! It is super important that this does not leak!!! You don’t want liquid getting into you electrical box.
Assembled the following parts using Teflon tape to complete the lower tee assembly:
  • 1 1/4" Stainless Tee
2e. Hose End Adapters1
  • 1/4" Male X 1/2" adapter
  • Hose Fitting Adapter, 1/2" NPT Male x 1/2" Barbed
2f. Outlet Box and Adapters
  • Single gang plastic outlet box
  • Outlet cover with a 1.3” hole drilled in the center
  • 1 1/4" Male X 1" adaptor
  • 5500W 240V Screw-In Foldback Water Heater Element - High Watt Density
Wire one end of a section of electrical cord to the heating element terminals and the other end to outlet box that will connect to your heater switch.

3. Complete the Heating Chamber

3a. Screw the two tee assemblies together.
3b. Screw the electric box to your base.

4. Attach the pump

I made a little housing for my pump. I will just pop out of its home for when I want to move it to another task.
4a. Attach valve and hose adapter to the pump output.
4b. Connect with a short hose to the heat chamber.
4c. Attach hose adapter and hose to pump input. This will connect to you mash tun.

5. Build the Heat Controller Box and Connect

5a. Make the Control Box and mount it to your base
5b. Cut holes for your switches and controller.
5c. Drill holes and insert rubber grommets to accept power cord input and output feeds.
5d. Install switches and controller into the case


6. Wire your RIMS up

6a. Black power lead and white neutral to pins 1 and 2 to power the controller.
6b. Black power lead to each switch inputs.
6c. Output of pump switch goes to the pump
6d. Output of heater switch to heat connect pin 5
6e. Output on pin 6 goes to the heater
6f. The neutral leads (white) get connected together and pair with the power lead outputs to go to the pump and heater outlets.
6g. Connect temperature sensor to pins 3 and 4.
I wired my heater and pump outputs to the electrical box. One socket for the heater. One socket for the pump. The pump and the heater can then plug into their proper outlet. I did this to make it more modular.
Dec 19, 2014
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West Palm Beach
Much improved - nice upgrades. You will be happy you did it. That said, the pump should also be replaced with a food grade unit. A fish pond pump may have unsuitable parts for this application. There are inexpensive ones many forum members use if you don't want to opt for a Chugger/March. Good luck!


Well-Known Member
Dec 5, 2007
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I would be a bit leery of using that Inkbird as a controller as it is rated for 10A for heating. I believe a 5500W 240V heating element run at 120V instead of 240V will draw 25% of the power or 1375W. That means the current draw is 1375W/120V or 11.5 amps but the Inkbird is only rated for 10A.


Well-Known Member
Oct 6, 2015
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20 mi North of Cedar Rapids
I'd still use a PID controller and a Solid State Relay instead. Cost would go up about $30, but you'd have much better temperature control and you wouldn't be hot switching a relay at 20A/220V hundreds of times per batch.


Supporting Member
HBT Supporter
May 14, 2013
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Rio Rancho
Nice article and appreciate your DIY, however, if you compare with some premade units out there, there are some very comparable bargains. For instance, Bobby's unit from brew About the same cost and much easier to clean and maintain. I started planning a build like yours and when I found this and priced all the parts it was almost a wash. Maybe $30 more for everything. Happy brewing!


Well-Known Member
May 9, 2009
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First of all Ted, thank you so much for editing your original article. The enthusiasm for your design was very much noted, and I can speak for myself by saying very much appreciated. Thanks for looking back into this and reporting back.
I do mirror the previous comment about the pump. I'm not sure that it isn't food grade (it didn't kill the fish), but I'm not sure that it is. It surely is atypical for this application or heat. Did you specifically get more information about that pump? If it's up to the task, it may well be a new solution for all of us to consider. If no, we are all the wiser, no judgement passed.


Jul 8, 2014
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The pump is a sealed pump with a magnetic drive and ceramic impeller, designed for aquariums and ponds. Since it is designed for live fish, I am not worried about any contamination.
I would be interested in the other pumps mentioned, if you have reference or link. Thanks!


Jul 8, 2014
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The pump is a sealed pump with a magnetic drive and ceramic impeller, designed for aquariums and ponds. Since it is designed for live fish, I am not worried about contamination. The only question I have is how will it stand up to the heat over time.
I would NOT select this as a first choice for a pump. I would invest in a pump designed for brewing. I had the pump, so I used it to save a $100+.
BrunDog pointed out there are other less expensive pumps that could be used for this application. I will would provably look into other options like these, if I were starting from scratch.
Thanks for your kind words. :)


Jul 8, 2014
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Yes, the controller was cheap. $15, I think. I could have upgraded the controller or maybe used a lower wattage heating element, to keep it closer to the specs.
After multiple batches, it has been holding up well.


Well-Known Member
Dec 6, 2015
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A convenient way to clean the RIMS heating element is an absolue must. Once a crud layer develops it quickly thickens and scorches. I got tired of unscrewing mine with pipe wrenches every time and got a triclamp fitting for my element.


Well-Known Member
Dec 6, 2013
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North Tonawanda NY
except the live fish arent drinking 150degree+ liquid out of it... at those temps a lot of plastics are leaching chemicals... there are a lot of better cheap options like the pps plastic tan food grade pumps many use. they are like $18 and good with boiling liquids. they have a coated magnet and ceramic shaft because they are designed to be food grade not fish grade.