The Bunn Express - model ES-1A

The Bunn ES-1A is a single-group, heat exchanger equipped espresso machine designed for commercial applications. It is a well finished machine with a gray powder coat and stainless steel exterior. The fit and finish are very good, and generally speaking it is an aesthetically pleasing machine.

The ES-1A has a massive chromed brass E61-type group head, with passive thermosyphon heat control. It has steam and hot water wands located to the left of the group, activated by levers at the bottom of the drip tray. The pressure gauge (a combo unit for the boiler and brew pressure) is located to the bottom left of the group and is easily read. The on/off switch is located to the top right of the group and is tucked safely out of the way, while remaining accessible.

Hook up of the ES-1A is similar to any other plumbed espresso machine. Mains water is connected to the machine via flexible tubing and waste water is carried away by large diameter tubing. As with any espresso machine, water quality is of paramount importance. Use of a water softener is recommended, with a reverse osmosis filter a second option. Mains water pressure should be controlled by an in-line water-pressure valve. It is possible to use the ES-1A without hooking it up to the mains. With the use of two five-gallon water bottles I am able to repair and test any direct plumbed espresso machine. The rotary pump used in such machines will suck water from a reservoir just as an oscillating pump will.

Reasons To Like The Bunn ES-1A For Home Use:

• It's smaller foot print takes up less counter space than other commercial 1-group espresso machines.
• A smaller than typical boiler means less time needed for warm up if not left plugged in 24/7.
• As commercial machines go the ES-1A is less intimidating than most.
• Repair and maintenance issues are simplified by the machines design; Removal of a few screws permits the side and rear panels to be removed for complete access. Once the exterior panels are removed the parts are laid out in a manner that makes working on the machine very easy.
• The ES-1A has circuitry that allows it to auto-fill the boiler without activating the heating elements. (A feature not available in some machines, such as Nuova Simonelli.)
• It's a simple process to program the automatic dosing switches and once programmed the settings are tamper proof.
• The pre-infuser is a very nice touch and can be left on or turned off. (A feature not available in some machines, such as La Cimbali.)
• Parts are readily available from various internet espresso parts dealers and are not overly expensive.
• It is an easy machine to PID (more about this in another article).

Reasons To Dislike The Bunn ES-1A For Home Use:

• Because it is no longer being produced, the Bunn ES-1A is scarcer than hens teeth.
• The scarcity of the ES-1A on the resale market makes it difficult to find one to buy. (Probably 1 or 2 can be found on eBay per month; often the same ones, just relisted.)
• It’s heavier than almost any machine designed solely for home use (but, in defense of the ES-1A, it is lighter than any other 1-group designed solely for commercial use).
• While the absence of a water reservoir, and having to provide for a waste water receptacle, might be a negative to some, it is also a plus in that an in-line water softener can be installed and the possibility of running the rotary pump while dry is greatly minimized.
• The drip tray has a design flaw that lets water run over the steel frame, causing the frame rust. A simple bead of clear silicone along the back edge of the drip tray grill solved the problem.
• The original blue/gray finish is admittedly, boring. (This is easily remedied by painting it or having it powder coated.)
• The noise of the pressure stat relays opening and closing is a bit disruptive, especially if the machine is placed near the living areas. (This is an easily fixed problem – simply PID the ES-1A, which I'll discuss in a this article.)

Living With The Bunn ES-1A In The Real World, My Home:

I’ve been using the Bunn ES-1A for more than a year now, and I can honestly say that I’ve never had better coffee prepared. I leave the machine of 24/7, meaning it’s ready to make me a great shot of espresso at a moments notice. Grind some beans, dose the filter, do the water dance, put the portafilter in place, and punch a button. Making coffee cannot get any easier than this and the quality is superb!

Would I recommend it to others? Most definitely, but with some reservations:

• This machine is no longer in production so it's sort of an orphan. Bunn repair centers will not support it and finding a repair technician willing to work on it is next to impossible.
• There is very little information available on repairing Bunn espresso machines. However, if you want one of these machines it's possible to apply techniques and knowledge learned from other makes to the Bunn machines.
• Because of the above I suggest only those with some working knowledge of commercial espresso machines and their internal workings consider this machine.

I did have a few issues that needed to be dealt with:

1. The PSTAT’s noisy relays were eliminated in favor of a silent PID kit that I put together myself.
2. The heat from the boiler being on 24/7, made insulating the boiler one of my top priorities.
3. I did get tired of the blue/gray finish, so I had it powder coated at the same time I did the PID conversion.