Mag pump issue

[UpTheToon]

I use a 12v mag pump from Home brew builder with my recirculating BIAB setup. I've had it about 7 months and done 12 or so brews with it.

On Sunday I noticed the flow was greatly reduced. After looking at the valves etc I couldn't figure it out. Cooling and running the 40 odd litres into the fermenter took forever!

I hoped it was the power supply (a decent LED 12v 3a driver as recommended on here) so ordered a replacement online to try that.

It's arrived and the pump is the same.

Anyone have any ideas?

[lord groan]

Going back to basics, if the volts/amps driving the pump are fine then either the pump impeller is worn in some way, there's been a build up of friction which slows the pump down or there is an obstruction somewhere in the circuit, I'd (carefully) whip the top off the pump if possible and make sure the impeller is clean and unworn and moves freely and that the inlet and outlet pipes are completely clear, check that there isn't a build-up of dried sugary wort getting in the way. After that it's the pipework , maybe pump clean near-boiling water from a pan through the system for a while, that should dissolve any dried wort deposits given enough time?
Good luck

[UpTheToon]

Thanks!

I didn't realise you could open them up without knacking them.

There were a couple of grains that must have made it past my bag and false bottom. Got them out and it's as good as new!

[ciderhead]

Always a good idea to run for 5 mins in hot water at the end just to rinse out unwelcome stubborn wort or grains

[50quidsoundboy]

i have the same pump. after every brew i recirculate boiling water with Oxi Clean followed by Star San and always thought that would do the job. recently i lost a couple of batches to an infection, and in the process of nuking all my gear, i took the pump apart - lo and behold, there was a fair amount of gunk / hop matter tucked away in there. once cleaned and reassembled, i noticed the pump had a lot more oomph.

be careful disassembling it though - although there are only a few parts and it is easy to reassemble, a couple of the internal bits are very small indeed and could be easily lost.