# Pump knackered?



## mremanxx (Dec 30, 2014)

I think my vibratory pump is a way on my Isomac

Pump stopping if I try to backflush so am presuming that it is stalling under load, having to pre infuse now as stops when gauge reaching 9.5 bar.

Anyone with knowledge agree?

Thanks


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## mremanxx (Dec 30, 2014)

Had hoped someone would have responded to this.

Can I ask other Isomac owners how long the pressure gauge is taking to reach maximun (9.5 bar) once the brew lever is pulled up fully?


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## DavecUK (Aug 6, 2013)

How old is the machine, has it ever had a new pump before, is it used in hard water, have you recently descaled, does the pump sound different all the time now or only when under load, is the water flow otherwise normal through the group, has anything else happened, have you recently performed maintenance on the machine......etc...



> Pump stopping if I try to backflush so am presuming that it is stalling under load, having to pre infuse now as stops when gauge reaching 9.5 bar.


What exactly does the above mean.

There is not enough information for any useful response, your pump may indeed need replacement, or it could be fine and there is another problem.


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## mremanxx (Dec 30, 2014)

Thanks Dave,

I started to notice that the time for coffee to drop from the PF was taking longer but all still worked fine.

I descaled and after that the pump noise drops significantly when you either pull the lever to the 45 degree angle or when the gauge hits 9.5 bar if you pull the lever all the way up. I also noticed that water comes out of the solenoid valve pipe, so am not sure if the descale may have done something.

TBH I think the descale is just a coincidence as I got nothing out, I live in Gods' country and our water is pure and as soft as a new babies bum









Opened her up to strip the pump but she is pretty deep inside so will wait for the new one to arrive before I replace, would hate to go without for a few days.

I cannot think of anything that would stop the pump working, unless do HX machines have over pressure valves/solenoids that are a safety etc that would stop the pump?

What my above statement meant is the following.

If I pull the brew handle fully up without a PF pump runs, water flows instantly. Pump and water will continue to run as pressure is only about 2 bar.

At the 45 degree angle my pump always ran and caused the pressure to go up to max but no water ever came out, pump would continue to run.Now water just comes out the overflow pipe in the water tank and pump very quiet.

If I install a blind basket and pull the lever, pump sounds normal until pressure at max then the pump goes very quiet and water comes out overflow.

However if I have the basket in and pull to 45 degrees the pump goes very quiet and the gauge goes to max almost immediately with water coming out the overflow in tank.

If I now try to pull a shot the pump is going quiet and nothing coming out the PF once the pressure reaches max, but if I preinfuse this allows coffee to flow as the gauge is only going up to about 8.5 bar.

Have gone for the pump as I presume this is going to be the cheapest initial option?

Any info would be appreciated.


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## DavecUK (Aug 6, 2013)

OK, as I wasn't sure if pump stopping meant stopping as in thermal cut out stopping.

I did ask how old it was, obviously that equates to continuous usage as an assumption, because if it's not very old it could be a blockage....45 degree angle is not really a thing, it just meant your brew switch is adjusted such that at 45 deg, the top brew valve in the E61 isn't open

It could be the pump, (unlikely on a machine less than 5-7 years old, but I don't know how old yours is), it could be a blockage, it could be wear on the top group pin preventing it from opening the top group valve completely, it could be a faulty expansion valve (OPV). The way the pressure gauge sits in the group circuit and with the relatively low flow of a vibe pump, it only really measures the full pump pressure during static conditions. If the flow rate is low, depending on conditions you can see quite low readings.


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## mremanxx (Dec 30, 2014)

Cheers Dave







making my day here.

Might phone Ian from espressotecho as I think he is the nearest repairer to me I live in West Lothian Scotland. Surrey is a little far mate.

I bought the machine second hand but the owner bought from new and it was only about 4 years old with light use.

Andy


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## DavecUK (Aug 6, 2013)

mremanxx said:


> Cheers Dave
> 
> 
> 
> ...


The pumps can fail at 4 years, but it's more likely some other problem rather than the pump. I've seen so many 8-10 year old machines with well working pumps. As for west lothian, you have some of the best water in the country, so it's unlikely to be scale...especially if the previous owner was in the same sort of area.

If water is coming out of the solenoid valve pipe, that could be actually where the problem is, either gunged up or the valve not sealing right....it's surprising how little flow might be required to drop the pressure of a vibe pump, especially as they get older. The vent tube (solenoid valve on the E61 is normally tensioned to go at 12.5 to 13 bar. Also just the word you used solenoid valve, confuses, as you might mean the autofill solenoid valve, which is actually the only solenoid valve in a lever operated E61 machine?


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## mremanxx (Dec 30, 2014)

Cheers Dave, the previous owner did indeed same in the same district which is why I was suspicious of scale.


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## MrShades (Jul 29, 2009)

Perhaps I'm being too simplistic - but if you get some sort of pour if you preinfuse but next to nothing otherwise then I'd suggest that the grind is too fine and its choking.

Have you tried simply backing the grind off a bit?


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## mremanxx (Dec 30, 2014)

MrShades said:


> Perhaps I'm being too simplistic - but if you get some sort of pour if you preinfuse but next to nothing otherwise then I'd suggest that the grind is too fine and its choking.
> 
> Have you tried simply backing the grind off a bit?


Unfortunately not, I cannot do a backflush now as the pump noise reduces severely, and as I just discovered the bypass hose is venting water back to tank, I think Dave is on the money about the solenoid valve.


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## mremanxx (Dec 30, 2014)

DavecUK said:


> The pumps can fail at 4 years, but it's more likely some other problem rather than the pump. I've seen so many 8-10 year old machines with well working pumps. As for west lothian, you have some of the best water in the country, so it's unlikely to be scale...especially if the previous owner was in the same sort of area.
> 
> If water is coming out of the solenoid valve pipe, that could be actually where the problem is, either gunged up or the valve not sealing right....it's surprising how little flow might be required to drop the pressure of a vibe pump, especially as they get older. The vent tube (solenoid valve on the E61 is normally tensioned to go at 12.5 to 13 bar. Also just the word you used solenoid valve, confuses, as you might mean the autofill solenoid valve, which is actually the only solenoid valve in a lever operated E61 machine?


Not too sure Dave as the diagram shows one solenoid and one autofill. Which do you believe may be causing the issue? (NO 19 or NO 31)

http://filer.kaffegrossisten.se/isomac-alba-reservdelar.pdf


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## MrShades (Jul 29, 2009)

Surely when back flushing the pump noise DOES reduce and the water SHOULD simply go back to the tank (via the OPV)???


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## mremanxx (Dec 30, 2014)

But much quieter than before, the first thing that drew my attention to this was the longer brewing times than normal for beans I have used before. Think it is just unlucky/wear and tear


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## mremanxx (Dec 30, 2014)

Forgot to add that my pump noise always stayed much the same when backflushing I would have thought that the only difference would be that water was being pumped to the tank rather than through the coffee but it should still be pumping no?


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## MrShades (Jul 29, 2009)

Well, when its pumping initially there'll be low pressure in the 'system' as it fills the e61 and blank basket with water - then once it's all full of water it'll be pumping against a brick wall (or a blank basket) and the pressure will rise (rapidly) to the point that the OPV diverts excess pressure (now all of it) back to the tank.

So usually when back flushing you'll get one noise for a few seconds and then it'll change and go quieter thereafter. On my Duetto with a rotary pump it probably takes 6-7 secs for this noise change and increase in pressure.


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## DavecUK (Aug 6, 2013)

mremanxx said:


> Unfortunately not, I cannot do a backflush now as the pump noise reduces severely, and as I just discovered the bypass hose is venting water back to tank, I think Dave is on the money about the solenoid valve.


if the Bypass is venting madly to the tank (or wherever it vents to), it could well be the expansion valve has a problem....of course there could also be a blockage further downstream, or a blockage in the autofill solenoid....becaise the hole the water goes thru in that solenoid is only about 1mm. Remember the expansion valve is typically set to 11.5 - 12 bar, so if it's coming out of that, either the pump is making 12 bar, or the expansion valve is faulty!


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## mremanxx (Dec 30, 2014)

New slightly larger pump fitted........back to normal yeh







Happy Bunny now.

Thanks for all the advice guys. Especially DaveUK


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