Grainfather pump issues

[Cobnut]

I am suffering what I see as a slightly strange issue with my GF pump.

On the last 2 brews, all has proceeded quite normally through, mash, boil and transfer to fermenter, but when it comes to cleaning usual approach has thrown up problems with the pump.

After the transfer to the fermenter, the GF gets emptied into the compost heap, given a rinse out with the garden hose (including cleaning the standard GF filter of accumulated crud). I then fill the GF with saved cooling water (clean, as it has only been through the CF chiller) and some Sodium Percarbonate cleaner and set the heater and pump going to clean out the GF and the CF chiller. This seems to work fine, but when I attempt to pump out the "dirty" water, the flow rate drops to almost nothing.

Cleaning out the ball valve - or indeed removing it - has little/no impact.

Switching off the pump and blowing back through the pump until it is clear of fluid seems to help, but often it then falters shortly thereafter.

I've done 44 brews on the GF and never dismantled the pump for cleaning in that time (close on 3 years), having heard from a number of GF users that there is no point as the pump remains clean for them.

Perhaps I should dismantle and clean the pump?

Or maybe my CF chiller has a build up of crud that Sodium percarbonate and other similar cleaners is not removing?

GF users, please help!

[Kingfisher4]

I remember a thread on here, which frightened me away from using readily available, unscented supermarket percarbonate to clean the Grainfather. Something to do with rate of oxygen release/bubble formation which can impair the pump I think.

I have stuck to PBW at 55°C, similar time brewing with the Grainfather, 66 brews so far. No pump problems. Not sure if that will be helpful or not, but someone will probably point you to the previous thread.

I may have misinterpreted the timing of your problem, I don’t use the pump to empty the PBW, manually lift and tip into the sink.

[AceMcAce]

Have you tried using the GF branded cleaner?

[f00b4r]

I remember a thread on here, which frightened me away from using readily available, unscented supermarket percarbonate to clean the Grainfather. Something to do with rate of oxygen release/bubble formation which can impair the pump I think.

I have stuck to PBW at 55°C, similar time brewing with the Grainfather, 66 brews so far. No pump problems. Not sure if that will be helpful or not, but someone will probably point you to the previous thread.

I may have misinterpreted the timing of your problem, I don’t use the pump to empty the PBW, manually lift and tip into the sink.

viewtopic.php?f=45&t=80226

[Dennis King]

I have had my GF for a year+ doing around 30+ brews so missed that thread about Oxi. I have found that Oxi, Tescos own brand added to the wifes weekly shopping, to be a better cleaner than the GF one. I still have some GF cleaner and have been using it occasionally to use it up. Never had any problems but now slightly concerned reading these threads.

[Cobnut]

I think I shall dismantle my pump and give it a good clean and inspection.

And also, find a way to thoroughly clean the CF chiller - perhaps by pumping some REALLY hot fluid through it. I usually clean at 60C, but maybe I'll try bringing some water to the boil and recirculating that through the CF chiller.

[PeeBee]

I think that linked thread (viewtopic.php?f=45&t=80226) probably had the answer.

The pumps are "impeller" types. The pump action is "open", not sealed like a tyre pump. So they are not "self-priming". During normal operation with a GF I frequently (when starting after a refill) have to switch the pump off and on again which always seems to clear the airlock preventing the pump from pumping. My 3V setup has loads of automatic bottle vents to prevent air stalling the pump in that.

Throw "oxy" cleaner in and volumes of bubbles are produced. The airlock in the pump is replenished and pumping stops.

I don't think there is a problem with the pump.

If I'm correct, don't leave a pump working in a solution of oxy unattended because it might stall meaning the pump is effectively running "dry" and could pack up terminally.

[PeeBee]

... And also, find a way to thoroughly clean the CF chiller - perhaps by pumping some REALLY hot fluid through it. I usually clean at 60C, but maybe I'll try bringing some water to the boil and recirculating that through the CF chiller.

A strong, hot, fresh solution of "Oxy" will sort out most potential blockages. My chiller got well blocked up with some sort of growth . After blowing it clear with about 10PSI of CO2, pumping hot oxy through it sorted out the rest (what I pumped out passed into a hop filter):

[Cobnut]

Thanks @PeeBee

Although I am slightly bemused at the apparent contradiction between your two posts.

On the one hand you're saying "don't use Oxy (in which the Sodium Percarbonate I'm using is a substantial ingredient) in hot water cause it'll generate bubbles which might stall your pump".

On the other you're saying "Oxy in hot water will clear any gunk out".

And the rest of t'internet is equally confusing regarding Sodium Percarbonate.

e.g. the Malt Miller website says "it's an amazing cleaner, best used at 60C" (which happens to be the temperature I set my GF at when using Sodium Percarbonate.

Whereas I found US site which says "use it in cold water or warm water, but not hot water"

[PeeBee]

I never said "don't use Oxy" (in a GF), only be aware of the hazards. And using it hot accelerates its decomposition so the solution won't last as long. Sodium Percarbonate is not "usual" as cleaners go. It's the (very!) transient breakdown products that do the cleaning/killing. When you see oxygen bubbles, that's part of the active principal after its done its job. Something about free-radicals; all a bit scary!

As for that picture I posted earlier:
https://www.youtube.com/watch?v=wkk1ohg99FY

[PeeBee]

If you want an example of "scary", I snipped out this of hydrogen peroxide breakdown (which is a product of percarbonate breakdown):

"superoxide (O2−•) and hydroxyl (•OH) radicals"

It's those dots that do the damage. Stay clear of better explanation, my experience of going down that avenue is panic attacks and fear of ever using the Percarbonate again. Ignorance is bliss ... actually this Prozac ain't too bad either.

[Carnot]

Pee Bee, the fact that you can freely buy oxi cleaners should tell you something. It is not that scary by any means. If it was you certainly would not be able to buy it at Tescos et al. It is a convenient way of handling hydrogen peroxide, generating it in situ rather than having a liquid, that in high concentration can be a little interesting. These days us proles can longer access strong hydrogen peroxide. The terrorists put paid to that. Sulphuric acid went the same way as certain idiots liked to thow it in the faces of women. The only way I finally got rid of athletes foot was to soak my feet in sodium percarbonate solution. It worked a dream - my feet did not suffer at all. Not exactly recommened but I researched the subject and realised the risk was minimal. No doubt you handle Starsan - now that really can be hazardous.
In cold water sodium percarbonate is slow to dissolve. In hot water it will be pretty lively. The thing to remember that it will raise the pH to 10 or more, which could be precipitating calcium carbonate, or even beer stone. I tend to use softened (sodium exchanged) water with sodium percarbonate. This avoids calcium precipitation. If there is calcium deposits or beer stone in the pump then sodium percarbonate or alkaline cleaners will not work. Then some acid will be required.
But it looks to me that it might be a case of cavitation. The gas generated by the rapid mixing of the percabonate might be causing the pump to cavitate.

[PeeBee]

Pee Bee, the fact that you can freely buy oxi cleaners should tell you something. ...

Teesh. Where's your natural sense of debilitating paranoia?

It's not "sodium percarbonate" that's the issue, it's that these mechanisms exist in the world, quietly waiting for their moment. I bet you are one of these wierdos that just jumps into bed without first checking what's lurking underneath?