Fun with a shower pump

[Chud]

My brother-in-law gave me a non-working shower pump to play with. Being an electrical engineer I naturally started by checking all the electrical par ts and could find no problems. It was interesting to see how it worked though, inside the inlet pipes are torpedo-like magnets which move up to switch on reed switches when there is flow. I shorted these out and the motor just hummed, so either the starter capacitor faulty or the motor stuck. In the end I took the ends off of the pumps and sure enough the pump spindl e was stuck. A few turns back and forward and it was freed. Put it back tog ether and all working well. A £300 pump revived. Thinking about it later I guess a plumber would have started where I finish ed and saved a lot of time.

[Scott M]

A plumber would have just replaced it. Partly as (IME) they don't understand the inside of things but because it's simpler and more profitful. Prosaically, as someone who mends many things, there's also always a danger that a fix won't stay fixed.

[Tim+]

Indeed. Why did the shaft seize? How long before it seizes again?

Tim

[GB]

Indeed. If you were doing this for a living, you would have to guarantee any fixes. So, if say 1 in 5 need replacing in the end, you'd have to add 1/5th of the cost of replacement (the item plus the extra call-out costs) to the price of every fix.

[T i m]

Whilst I'm not questioning the potential of the 'fault' returning, I have freed many a CH pump that was simply 'bunged up' with cr*p that had ended up in the pump and stopped the pump re-starting, typically when used for the first time after a break.

So, whilst the pump my stop again in the future, it could simple be because there is a lot of mobile cr*p causing it to do so?

I got a Dyson cylinder off Freecycle because the owner had it fail on them, paid to have it repaired, then it failed 'again' and, not wanting to spend any (similar) more money on it, bought a new one. I just replaced the plug (due to a broken wire going into the molded plug) and it's been fine ever since. ;-)

Cheers, T i m

[Andrew Gabriel]

A common cause of this is the axial shaft seal has failed, and leaked water which has found its way into the bearings, generating rust. Replacement ball bearings are easy to find (they often use the same size which skateboard wheels use). Shaft seal can be harder depending what type it is, but before replacing, you need to clean up the shaft where it passes though the shaft seal - spinning the shaft in a plastic pan scourer can work (don't melt it), or fine steel wool in bad cases.

You may need a bearing puller to get the old bearings off the shaft, although often they slide off easily. If the shaft has gone rusty too (which doesn't often happen), you probably won't be able to get the old bearings off, and then it's really had it.