ET-8550 - Repeated ink filling over 2/3 of the ink tank could damage the printer.

[Epatcola]

I saw this mentioned on DPReview (where I don't participate) and thought huh?
So I checked and there it is:

The only thing I can think it might be talking about is that inserting the bottle always releases a little ink and doing that repeatedly could fill the tank past the normal automatic cut off level.

 

[ThrillaMozilla]

That's for a different printer. I looked at the ET-8500 manual and didn't find anything like that. The only thing is that they mentioned that for optimum results it's good to top it up to 100% at least once per year.

 

[Epatcola]

That's for a different printer. I looked at the ET-8500 manual and didn't find anything like that. The only thing is that they mentioned that for optimum results it's good to top it up to 100% at least once per year.

It is a photograph of my ET-8550 screen. Automatically presented when you open the ink tank cover.

 

[Loomray]

On my ET8550 with the newest firmare OP28P8 ,i have the same information(in German), when the Ink tank cover is opend.
From my understanding, you have to wait when your ink level drops under the 2/3´s ,to fill it up(with full bottle of ink)
I think it has to do with the hydrostatic-pressure which could be to high for the dampers to fill it poperly ,or the Valve in the bottle can only close fast enough ,when some amount of ink is out of the bottle.

 

[Epatcola]

I couldn't find any good information or diagram of how the automatic level cut off works. I suspect in principle it is something like this

The filling tube is on the left and a breather tube capped with breathable film is on the right.

The bottles sort of 'glug' when filling and I suspect an amount of head is required to form an air bubble in the bottle nozzle and let more ink out. When the tank level reaches the bottom of the breather tube ink has to flow up it reducing the amount of head the bottle sees and at some point stopping the flow.

You have to put some more ink into the tank to pressurise the air in it and fill the breather tube for the flow to be cut off.

If you repeatedly stick in the bottle you will overfill the tank and if the ink reaches the breathable film it will be clogged and ruined which would be the printer damage in the warning.

The breathable film is required to let air molecules in and not let liquid molecules out so the tank can be vented without evaporating the ink.

That film would also be how you damage the printer by putting it on its side or upside down with ink in it.

 

[ThrillaMozilla]

Thanks for this information. I don't really understand it, but I will take note.

 

[bplaman]

I saw this mentioned on DPReview (where I don't participate) and thought huh?
So I checked and there it is:
View attachment 17881

The only thing I can think it might be talking about is that inserting the bottle always releases a little ink and doing that repeatedly could fill the tank past the normal automatic cut off level.

Here is the answer from the artificial intelligence Grock:

The message on the **Epson EcoTank ET-8550** (or very similar model) — **“Repeated ink filling over 2/3 of the ink tank could damage the printer”**.

### What it actually means
This is a **warning from Epson** that appears on the printer screen when you try to refill ink while the tanks are already more than ~2/3 full.

### Why the printer shows this message
- With **original Epson ink bottles**, a special key-valve automatically stops filling exactly at the upper mark (full tank). Overfilling is physically impossible.
- If you use **third-party (compatible) bottles**, refillable tanks, CISS (continuous ink supply system), or pour ink with a syringe/funnel — there is no valve, so you can easily overfill.
- The printer **detects** that the ink level is already high (above ~2/3) and issues this warning to protect itself from overfilling.

### Why overfilling can actually damage the printer
- The tank needs a small **air pocket** at the top for correct pressure regulation and to compensate for temperature expansion of the ink.
- If you fill “to the brim” or above the upper line:
- Ink can leak inside the printer during transport, tilting, or even from vibration.
- During printing or head cleaning, excess pressure can force ink into tubes, the pump, or onto the main board → corrosion, short circuits, and expensive repairs (often the whole main board has to be replaced).
- In severe cases, ink floods the print head and kills it.

### What to do
1. **If you use genuine Epson bottles** → this warning almost never appears because overfilling is impossible.
2. **If you use non-original ink or refill manually** → the printer is specifically warning you: do not top up if the tank is already more than 2/3–3/4 full. Better to wait until the ink drops to half or lower.
3. To clear the message — just press OK or finish the refill procedure without adding more ink. The printer will work normally afterward.

In short: it’s Epson’s protective measure against careless refilling with non-original ink. As long as you don’t fill the tanks completely full (“to the neck”), there will be no problems.

 

[Epatcola]

Here is the answer from the artificial intelligence Grock:

That is a great example of eloquently stated drivel made up from crap it read on the internet.

I can't see a single correct statement in it.

This is supposed to be the future? Wait till people stop bothering to put anything on the internet because AI scraping engines are the only thing reading it. Without crap from the internet the AI will have even less to regurgitate.