Cleaned boiler with baking powder, now it won't heat up. Fuse or worse?

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#1: Post by nickdunc » Apr 28, 2013, 12:26 pm

In an attempt to do a little housekeeping I was cleaning the inside of my Europiccola with baking powder as recommended on a site I had visited. What happened was a lot of water and steam all over the place. I turned off the machine but it would no longer heat (i.e. the red switch would not illuminate nor heat water).
I should say that the machine appears to be from the late 1980's and has a double power switch (white and red). It does not have a re-settable fuse. What it does have, which is what I take to be the fuse is an F-O-D Microtemp. This shows off range resistance, (1) on my multi-meter. I'm assuming that this is the problem and that this needs replacing.
I'm not an electronics buff, but would like to learn how to maintain this unit.
Would the best course of action be to order a replacement thermal fuse? If so does it have to be for a specific model (I don't know for sure which generation this is), should I only get this exact fuse, or will any fuse they currently sell actually be better?
I am hopeful that the element has not been damaged - it appears to have resistance on both elements.
In recent weeks the on switch has needed an extra push to engage (it has a plastic cover on it). Would it make sense to replace this at the same time in case it too has been damaged?

Many thanks for any advice.


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#2: Post by homeburrero » Apr 29, 2013, 4:23 pm

nickdunc wrote:what I take to be the fuse is an F-O-D Microtemp. This shows off range resistance, (1) on my multi-meter. I'm assuming that this is the problem and that this needs replacing.
Your assumption is correct, that fuse should show low resistance. Is it a thermal fuse inside the red rubber tubing? You can buy a replacement for that at an appliance shop or a Radio Shack (e.g., ... Id=2062259)

The switch is available at Stefano's Espressocare or at OrphanEspresso (both are sponsors of this site.) You may want to save on shipping and put together an order for a rebuild kit and a switch to have on hand, along with any other goodies from them that catch your fancy (Elektra basket? single-hole tip? espresso cups? descaler? funnel?) But for now you can simply replace that thermal fuse with a generic part of the right temp (128C is fine.)
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#3: Post by pocojoe » Apr 29, 2013, 7:45 pm

Baking Powder? Baking Soda? I gotta ask-

I have heard of using Creme of Tartar as a boiler descaling agent. I believe it is in Baking Powder, but there is also sodium bicarbonate to make it pH neutral. Baking Soda produces C02 and neutralizes acid.

How well does Baking Powder work compared to say, citric acid?

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#4: Post by iginfect » Apr 29, 2013, 8:31 pm

A descaler solution must be acidic to dissolve the calcium carbonate. Sodium bicarbonate, baking soda, is basic and won't work. Cream of tartar, potassium bitartrate, also known as potassium hydrogen tartrate, a weak acid, is the potassium acid salt of tartaric acid, a carboxylic acid. It is most likely more expensive than citric acid and wouldn't work as well. Its role in baking powder is to react with the sodium bicarbonate, a base(alkali), as an acid base reaction and release carbon dioxide, which makes the batter rise.


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#5: Post by homeburrero » Apr 29, 2013, 9:13 pm

I suspect that Nick meant baking soda rather than baking powder. It is commonly recommended for cleaning coffee stains from mugs and coffee makers.

Which brings up an important point - descaling boiler internals, and cleaning of coffee residues are two very different processes that should not be confused. To you clean your portafilter or the inside of your dispersion screen you need a detergent that dissolves coffee oils. You don't have coffee residues inside your boiler, and you don't normally clean it with detergent. But when it is building up a little limescale you need to dissolve that with an acidic descaling solution. You can buy compounds for either function. (You can even buy yet another detergent that is formulated to clean milk residues) and you don't want to confuse them.

For descaling a Pavoni, a 50% white vinegar solution is often recommended. You fill the boiler with that, then let the thing heat up and sit an hour or two, flush a little of that solution through the group, then cool, drain and inspect, and repeat if you still have scale. Finally rinse and rinse til all the vinegary odor is gone. You can also use a citric acid solution (one tablespoon of citric dissolved in 1 quart of hot water.)

See How to descale chrome components without damage? for a Pavoni owner / chemistry professor's discussion of vinegar vs citric acid.

I now see that the OP is in the UK, and in my earlier post I recommended a couple US shops for parts. I'm sure there are similar shops in the UK that sell Pavoni kits and parts, just don't know which to recommend.
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