Introduction: Fix My Flexbrew!!

By
About: I work in industrial automation and spend any free time making.

I've had a lot projects in partial completion but this particular one turned into a must finish situation. Basically our coffee pot went south. And once again I find myself in the coffee pot investigation and repair business. (See my other Keurig fix)
This in trustable will cover an overview of the Hamiltonbeach Flexbrew coffee pot. For anyone with this coffee pot having issue I going to break this report up into 2 sections. The first section will be just the facts weak points in the design how to quick fix.
The latter half will be where I show how to dismantle the coffee maker and see behind the curtain to the mechanics.
So lets get started.














Step 1: Flexbrew Review

This Hamilton beach Flexbrew was gifted to us over the holidays. It worked fine for the most part but to be a simple 1 cup brewer It is a bit bulky (Yeah yeah it does do other things but the other things seem more like a free gift to distract you from how big this thing is)
Yes It does other things as well it can brew grounds or K-cups and has a 2nd boiler for water dispensing only. If you do use this feature it is nice as your water does not get a coffee stained flavor.
The overall function of the brewer is similar to the Keurig I worded on in my other instruction on said brewer. But the Hamilton beach Flexbrew is simplistic you pour in the amount of water you want brewed it boils and brews all the water it has in the boiler. Etc etc pretty simple (yet sooo big)
After a few uses I started to notice the lid for the k-cup clamp / seal was a bit under engineered. The large skirt seal would leak because the approach angle of the lid as it hinges over does not allow the skirt seal to nest properly one corner will usually fold inward and a small leak will happen. See above pic.
That being said I will clarify the leak does not make it out of the brewing chamber area so no counter top mess just loose grounds in the needle area.

Next the Hamilton beach Flexbrew- brewing issues started.( HBFB for short)

More on these in the next step.







Step 2: Brewing Issues

Issues you will likely have if you have one of these Hamilton beach Flexbrew coffee machines.
1. Grounds all over the k-cup area
2. Sometimes will not brew although the pump will run.
3. Amount of coffee brewed varies from the water you put in.
4. Needle that punctures the k-cup will clog with grounds

All these issues above began to progress within 2 weeks of using the brewer and I will note I am the only coffee drinker in the house and average 1.25 cups a day. By the numbers not a good success rate for the Flexbrew.

What I found is the root cause of all these issues are the same thing. The poor lid design.

Next the breakdown how does the lid cause all this havoc?


Step 3: The Lowdown

When my Flexbrew started 'acting a fool' (its a technical term) I had to remove the lid clamp cover to clear a needle clog. And then i had to do this a few more times soooo I decided to do a series of tests with the lid exposed and find the root cause and a fix.

I will refrain from the details because it was myth busters type 'don't try this at home' stuff. Boiling water/electricity/pressurized tubes = bad things can happen. I am an automation professional etc etc LOL. (I did spray hot water all over the kitchen, and I'm pretty sure the return policy is out the window from here in)
So after poking this and prodding that and directing the other thing....
What I discovered is the inconspicuous looking bumper on the left side of the lay down
Surface seen in the first pick above is not a bump stop to match contact pressures with the lid closed switch opposite it!??
It is an active mechanical switch.
I observed holding down the lid closed switch and NOT holding down this bumper on the left the pump would run but no flow would result in the output tube (side note fluids 101 pumps do not create pressure only flow) LOL
Also if the bumper was not depressed firmly (like the weak lid would do) some flow would result but quantities were varied.
These observations led me to believe 1. this bumper was the afore mentioned some sort of air port seal. And 2. this machine was using an air pump. The bumper plug must be creating a dump path when it is not sealed. / path of least resistance all or most of the air never cycles into the boiler tank to push water out.

But this hypothesis would have to wait to be confirmed.

If you don't care about the gory details and don't care to take your Flexbrew apart follow the quick fix note below (all be it at your own risk/ results may vary) and be done.

If you want to tear your coffee maker apart read the fix below and continue on please.



-----Quick fix-------

To rig your Hamilton Beach Flexbrew you will need a pencil or ball point pin.

Now jab on the top of the left hand side lid bumper/ port seal pushing the center bumper down into the housing so that it is blocking this exhaust in a semi permentant fashion.

Now your machine should produce constant flow and brewing. In my case this fixed all my issues. I can not promise it will fix your issues. But if you are reading this instruction you are probably pretty mad at your fancy coffee machine right now anyway and what do you have to lose right??






Step 4: Lets Take It Apart!

At this point I had fought this Flexbrew all morning for a single cup of coffee. The quick fix seemed to work very well i trsted it out over and over and over and over but did not satisfy my peaked curiosity.

So I did what any maker would do and decided to take this Flexbrew completely apart, (you know... to verify my hypothesis and generally see what else I could hack on this brewer.)

This machine is easier to take apart than the Keurig I worked on before. It is held by simple screws. None of that rubrics cube plastic locking latches etc.

If you wish to follow this path, well you write your own destiny. I can't be responsible for what happens to your coffee pot (or you)

First: unplug the machine

2nd: dump all the water from the 2 tanks.

3: Look for the circle disks and pop them out. These are the screw caps. The pics above are reference for the different screw points around the Hamilton beach Flexbrew. Then just Remove all the screws in the exterior that you find.

The bottom does have security 3 slot bolts but these will come out with the right small flat head and pliers for grip.











Step 5: The Hack

Once stripped bare it is clear to see that bumper that I plugged in the earlier step is a dump valve of sorts. When the port is not sealed this becomes the path of least resistance for the pump air flow. Therefore no pressure will build in the boiler tank = no brew.

Also once seeing the machine stripped bare I decided I liked it better this way. Why not have a minimalist brewer.
First I decided what I wanted to keep and learned what exactly did this machine need to work.

The tank filler plunger was discarded.
The air port switch and Tee was discarded.
The secondary boiler pot was removed.
( I want to use this as a potable camper water heater.)
Next the needle assembly and chassis top cap plastic was trimmed with a dremel tool, keeping only what plastic was needed.

I used some hobby mending straps to create a simple mechanical cam latch for the needle sealing assembly.
The air pump and controls where re-mounted as seen above.
The support stand offs were bent using a heat gun and repurposed in the locations seen above.
I added a hacked cheap plastic bin to use the extra boiler space for storage/ everything/ coffee/sugar/spoon at point of use.
The rest of the odds and ends are just random bling.









Step 6: Closing Thoughts

A few side notes. To function I had to retain the temperature transducer from the bottom of the secondary boiler. This is the component that plugs into the yellow terminal on the control board. I plan to meter this later and did a resistor etc to replace it. With out this connected the unit will not deploy a fault message but will not go active via the ON/brew start button.

I know some may say this is dangerous with the boiler exposed and what not bla bla bla. But I say no more dangerous than the huge burning hot exposed coils of your stove top. But yes it is different and did I say will void any return policy.....
On that bomb shell..... Be safe. Have fun.