Suspect rotary pump needs replacing. Check valve chattering.

Equipment doesn't work? Troubleshooting? If you're handy, members can help.
seoras

#1: Post by seoras »

Before I dive in and spend good money on a new rotary vane pump for my E61 I just wanted to gather a consensus that my diagnosis is correct.
The check valve (non-return valve) that comes between my pump and the thermosyphon loop is making a lot of noise.
I replaced it but it didn't fix the problem.
It vibrates like an angry bee and you can feel it doing this if you hold it when the pump is on.
It's like the plunger inside of it is firing back and forward like a piston in an engine.
So my conclusion is that the rotary vane pump is at fault and that mostly likely one of the vanes is broken or malfunctioning which causes the irregular flow of water to make the check valve chatter.
Interestingly the check valve does the same thing when the machine is off and I run mains pressure water (3 bar) through it with the E61 open.
The pump still manages to get up to 9 bar of pressure.
The other tell tale is that the pressure manometer vibrates instead of sitting at a steady pressure level.
Am I correct or is there another possible reason?
Is there an easy fix for the pump instead of replacing it?
Thanks!

Giampiero

#2: Post by Giampiero »

Do you hear the same rattling sound while the pump refill the boiler?

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seoras (original poster)

#3: Post by seoras (original poster) » replying to Giampiero »

No.
Sorry meant to state that. When I run the hot water and the pump switches to boiler refill things are quiet. Just the hum of the motor and pump.

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BaristaBoy E61

#4: Post by BaristaBoy E61 »

seoras wrote: Interestingly the check valve does the same thing when the machine is off and I run mains pressure water (3 bar) through it with the E61 open.
The pump still manages to get up to 9 bar of pressure.
It doesn't seem like the pump is defective. Perhaps it's an OPV/anti vacuum valve that's not functioning properly.

Are you feeding your machine non-scaling water?
"You didn't buy an Espresso Machine - You bought a Chemistry Set!"

Giampiero

#5: Post by Giampiero »

What machine is it?

seoras (original poster)

#6: Post by seoras (original poster) »

BaristaBoy E61 wrote:It doesn't seem like the pump is defective. Perhaps it's an OPV/anti vacuum valve that's not functioning properly.
Are you feeding your machine non-scaling water?
Yep. Actually too pure. Tank collected rain water. That was a problem in itself until I added a water ioniser.
The machine was over filling its boiler due to the water having no conductivity.

Got the machine 2nd hand a year ago and it was badly scaled but I did a good job of cleaning it. That included the OP valve.
I didn't check the check valve though and up until about a month ago when the machine was heating up the pressure gauge would go up to 12 bar.
So I know the OP is working fine because that is what it is set to.
It would appear that the check valve was never working because the pressure gauge measures before the check valve.
So with my super pure water (I only added the ioniser recently) the machine has been getting stripped of all the remaining scale and I think that was what freed the check valve which, when it started working, made that noise.

I asked somewhere else and someone suggested "The internal bypass on the pump may be causing this."
Not sure what they meant by this?
Is that the pressure setting nut on the side of the rotary pump?
Giampiero wrote:What machine is it?
Sanremo Treviso

Giampiero

#7: Post by Giampiero »

Yes maybe even the pump bypass ( the pressure setting nut on the side of the rotary pump) could be eventually a cause, try to loose it a bit to see if the rattling sound it still or reducing.
By the way do you have any external pressure reducer on the inlet line?
Another simple ( seems you are enough familiar with tools) test should be to remove the steel ball from the check valve, if is the type with the viton seal, just remove the whole seal assembly.

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DaveC

#8: Post by DaveC »

To the OP, perhaps post up a video, it might be cavitation.

How old is the machine?

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BaristaBoy E61

#9: Post by BaristaBoy E61 »

Does opening the steam valve change anything when this happens?
"You didn't buy an Espresso Machine - You bought a Chemistry Set!"

seoras (original poster)

#10: Post by seoras (original poster) »

Giampiero wrote:Yes maybe even the pump bypass ( the pressure setting nut on the side of the rotary pump) could be eventually a cause, try to loose it a bit to see if the rattling sound it still or reducing.
By the way do you have any external pressure reducer on the inlet line?
Another simple ( seems you are enough familiar with tools) test should be to remove the steel ball from the check valve, if is the type with the viton seal, just remove the whole seal assembly.
I do have an external pressure reducer on the inlet line.
Since my home water comes from a pump outside near my water tanks it pressurises at 9bar.
I've placed a pressure reducer just before the water ioniser cartridge.
The machine reports the line pressure to be at 3 bar when the pump isn't running.
The water coming out of the cartridge splits to a drinking water tap and the coffee machine.
Nice steady flow of water coming from the cartridge (Edit. Just measured line water flow rate as just over 100L/h. Pump is rated at 50L/h).

De-balling the check valve is similar to what the Sanremo service agent suggested which was to put silicon grease on its o ring.
That just results in covering over what the underlying problem is.

The sound wasn't there this morning, or it was a good bit quieter. I wonder if whatever the cause is is perhaps self righting itself (freeing).
I'm not going to do anything too drastic yet until I really need to.
DaveC wrote:To the OP, perhaps post up a video, it might be cavitation. How old is the machine?
I dismantled and re-calibrated (to 12 bar) the OP when I first got the machine and descaled it.
It's just a simple spring mechanism and the spring is still good and tight.

Machine manufactured date is 06/2012
BaristaBoy E61 wrote:Does opening the steam valve change anything when this happens?
No, Why would it? It's an HX machine so the steam valve isn't part of that circuit.