Hi folks
This may be a dumb question but....
Was looking at my VBM double boiler to diagnose for potential pump issues.
Linked here: Question on high-pitched noise from rotary pump
Will post videos on this shortly in that post.

However, during this diagnosis I noted that the Fluid-o-matic pump was HOT. Like nearly group-head hot. Certainly not able to touch for longer than a second.

I realise that the pump is to the boiler by 2 pipes. So I guess it would heat by conduction but I was surprised it was that hot!

It cooled (of course) when the boilers refilled, with cold water running through it. However in a matter of minutes is was hot again.

Is this normal? I'm wondering if there is a one-way valve failing.
I should add by the way that the pump is still making a low ticking noise (more on this in the other post), but not making a whining sound.

Regards
Raymond

Hi, it is a failed non return valve situated between the pump and the the brew boiler. I could not find a pic of one on the net. The noise you heard would have been the graphite vanes scraping on the walls of the pump due to it being hot.

In my experience it is the o-ring that is cracked or has dislodged from its recess and is stuck open.

Craig

See pic below . . . not necessarily a fun disassembly job. You will very likely need a new pump.



Lots of good VBM info here - http://www.espressomyespresso.com/ and here - http://espressocare.com/ .

Thanks guys. Makes sense.
There is a delay from activating the brew boiler to water coming out. I guess water is flowing back from the boiler and group head due gravity, with the failure of the one-way valve.

Hi All
Just thought I'd capture everything in case others can learn from my experience.

First the good news: My baby is repaired and running well.... fingers crossed....

The diagnosis from HB'ers was correct. It was a failed non-return valve. The failure obviously caused hot water to run back into the pump, making it very hot.

Fortunately I didn't leave it like that too long... The pump seems to be running fine now. Good pressure generated, no ugly noises. So "whew" (at least for now...) big cost avoided...

Replacing the valve was pretty awkward. Have a roll of plumber's tape handy.
For the Vibiemme, the fitting is 21mm (the socket you need).

I checked the faulty non-return value by blowing air the wrong way. Indeed, air was able to pass backwards, confirming the fault.

Big thanks to Graig aka craigcharity and Eric Svendson aka erics

The next step is to consider the possible cause of the failure.
Is the machine plumbed or running on the reservoir?
If plumbed, what filtration/treatment of the water are you using?
If reservoir, is the filter in place on the pickup hose?
In both cases, have you tested the water for scaling potential, and have you removed the mushroom and inspected it for scale?

Randy G. wrote:The next step is to consider the possible cause of the failure.
Is the machine plumbed or running on the reservoir?
If plumbed, what filtration/treatment of the water are you using?
If reservoir, is the filter in place on the pickup hose?

Thanks Randy.
It is running from reservoir. It does have a fine filter over the nozzle. I did notice some floaties in the water but the filter is very fine and wouldn't pass these.

Water in Singapore is quite soft. The retailer whom I bought from said I never needed to descale while in Singapore.
(Anyone to validate or invalidate this position is welcome.)

Randy G. wrote:In both cases, have you tested the water for scaling potential, and have you removed the mushroom and inspected it for scale?

Sorry, what does this mean? Testing for water hardness with chemical test? Not sure what a mushroom is
I'm very much keen to track down root cause - lord knows I don't want a repeat !!
I tried to take the failed no-return valve apart, but without a bench clamp and better tools, I just couldn't generate enough torque...assuming that it unscrews...

Start with the PDF of the Insanely Long Water FAQ for more information on scaling.
Basically, it states that you need General hardness and Carbonate hardness (GH + KH) together to create scaling potential.
AN easy and accurate test kit is THIS one.
I always suggest testing the water. I would not bet my machine on advice from the person who would profit from machine failure to tell me the water is OK.
For more detail on the E-61 group, see these two articles on my website:
How-To 18 - Simple Lubrication of the E-61 Group
How-To 19 - Overhauling and Lubricating the E-61 Group. This will cover removing the mushroom. Pull it out, let it air-dry, and it will reveal is any scale has accumulated. It is merely an indicator. If there is scale, it will probably be heavier in the steam boiler.

And if you have not done so, download the USA owners manual for Vibiemme DD HERE. It has a lot more info than came with teh machine from the factory.

Appreciate the info. Will look into this.