OK - long story short - had a bunch of kids and haven't descaled in forever. Machine running pretty well using brita filtered water, but I know scaling needs to be done, and I'm assuming it's not pretty. I've read the old descaling / simplified descaling guides from Water, Scaling and Descaling with HX machines?, but they seem to be for responsible people that change their oil every 3000.000 miles Are there any instructions for people who assume they probably have a pretty hefty amount of scale build up?

What's your machine? Do you have an E61?

If so, check the mushroom first. That's a good indicator of scale in the machine. See this link:
Checking an E61 Espresso Machine for Scale

If you look at some of the machine restoration threads, you'll see what it takes to remove scale from heavily abused and neglected commercial machines. The most extreme cases usually involve taking out the boiler and all the fittings, then dumping everything in a muriatic acid bath for hours. The before and after pics are pretty eye opening.

However, your machine probably isn't as bad as that. I'm guessing that prolonged soaking in a citric acid solution without disassembling the boiler will do the trick. As canuckcoffeeguy recommended, the best approach is to check for scale on easily accessible parts like the group mushroom if it's an e61. Otherwise, you could remove a fitting on the boiler (with the machine off, depressurized, and unplugged of course) and look inside the boiler to see if there's a lot of scale buildup. Depending on the amount of scale, it may or may not need more extreme measures to remove the scale.

Also, be aware that aggressive descaling can lead to unforeseen consequences, like pieces of scale coming loose and clogging valves or other crucial bits. If you're in doubt, you might want to consider taking in to a professional for descaling and other routine maintenance, like replacing seals and other parts that might be on the verge of failing.

Oops - yes, e61. When I first got the machine and I took the mushroom out, scale came out of it like it was gravel. I wish I had one of those fancy plumbing fiber optic cameras where I could check out the interior.

How strong of citric acid solution could I use without causing damage? I unknowingly caused a problem when I backflushed with detergent right after descaling and caused damage to the chrome parts internally and had flecks of chrome coming out the boiler for a while.

Ozark_61 wrote:Oops - yes, e61. When I first got the machine and I took the mushroom out, scale came out of it like it was gravel. I wish I had one of those fancy plumbing fiber optic cameras where I could check out the interior.

Like this fancy $6.68 one?

http://www.ebay.com/itm/2-5-7-10-15M-6L ... 1809811101

(BTW, found this today in another thread in this very forum!)

Woah! Does it work???

I have no idea but it's sure worth a try
EDIT: you can use the same keywords (USB endoscope borescope snake inspection camera) and find tons of models on Amazon & the like too. They seem mostly waterproof too.

Of course, I'll have to use one for the machine.. another for the sewer line... and ne'er the twain shall meet...

Never cross the streams. This would be bad.

Mixing citric acid/sour salt for decalcifying / descaling

If that does not work, you may need to disassemble the machine completely, drop it all in a tub full of hot muriatic acid or sulfuric acid which can be a little dangerous.