- This topic has 5 replies, 2 voices, and was last updated 16 years, 7 months ago by
.
-
Posts
-
Hi,
My Ariston AFA250 is playing up. The upper spray bar won’t rotate, but sprays water in a stationary position.
I’ve spent most of today completely stripping it and cannot for the life of me work out what the fault is.
Both spray bars are free to rotate by hand with no resistance, the seal at the spray bar feed pipe looks fine (the one at the back where the water feeds up from the pump) and the little plastic ball that seals off the unused feed (for higher or lower tray positions) also seals well. The holes on both spray bars are clear and clean.
I’ve had the main pump motor off and removed the impeller – no damage, but it does seem to be weeping from the bearing and there is evidence that it’s been dripping a little onto the motor casing and then onto the floorpan. The impeller looks fine. I removed the paddle from the ‘half load’ valve in the impeller casing as I thought it might possibly be flipping up and restricting the flow to the upper spray bar (I never use the half load setting anyway) but it’s made no difference. I’ve also tested the startup capacitor with an DVM and it charges up as it’s supposed to and is not shorted (resistance >30Mohms when charged). The motor looks fine. All the filters and pipes are clear.
The only thing I can think of is that perhaps the pump is sucking in air through the worn impeller bearing and reducing the efficiency of the pump. Is this feasable ? When I started it up with the back off, you could see a few air bubbles in the water going up the riser pipe to the upper spray bar.
I’ve tried running it without any filters at all (empty and clean water only) and the bar just about rotates – but nowhere near as much as the bottom bar. Incidentally, the bottom bar rotates at approx 90 RPM (in case this is an indicator of something !) whilst the upper bar sits still and just sprays water.
I’m going to replace the impeller anyway as I think the weeping there is possibly related to the intermittent (but rare) occasions when the machine trips the house breaker (usually only happens if I open the door whilst it’s running). One other thing… now and again it will finish the cycle but instead of the last LED flashing as it should, it flashes the second one instead. I have no idea what it’s trying to tell me on that front !
I’m completely stumped. Can anyone suggest anything ? Please !! ???
Re: Completely stumped ! Help !
The circulation pump is almost certainly the culprit. If the shaft seal is weeping the water will be getting into the front motor bearing, which can make the motor run slow.
The other possibility is that the machine is underfilling – try adding a couple of extra pints of water after circulation starts.
Penguin45.
Re: Completely stumped ! Help !
The motor spindle turned quite freely between my fingers when the impeller housing was off, and there wasn’t much resistance with it on to be honest. The bearing didn’t feel stiff or rough.
The machine is filling to about 7mm below the overflow drain holes, but I’ll give it a go with a couple of pints more on the next run.
Incidentally, is it usual for the black insulation around the tub to melt ? Mine looks like it’s been going soft and sagging down the sides ! The machine is about 5 or 6 years old mind.
Re: Completely stumped ! Help !
Water level sounds about right TBH. Have you had the top spray tube off?
The bitumen insulation slumps with the heat – nothing to worry about.
Penguin45.
Re: Completely stumped ! Help !
I’ve had everything off ! Top bar, bottom bar, riser pipe, motor, impeller. Everything is clear. Double checked. There are so few components in this it’s got to be the motor or the impeller – I can’t see any other reason why the upper bar wouldn’t spin if it’s not insufficient pressure. The upper bar is plastic and the lower one stainless – the holes in the plastic upper bar can’t enlarge with age can they ?
I’ll order a replacement impeller unit and get a new motor capacitor just in case.
In the back of my mind, I know this is going to turn into one of those ‘DOH !’ moments, where it turns out to be something staring me in the face all along 🙂
Re: Completely stumped ! Help !
I don’t suppose anyone knows how tight the impeller should be screwed in do they ? It’s a left hand thread onto the motor spindle and I’m just wondering if it should be tightened just enough to hold the impeller central in the pump housing, rather than all the way ?
Also the capacitor doesn’t seem to have any terminal identification, so I’m presuming it makes no odds which way around it’s connected ?
Edit: Well, I put it all back together, and it’s made no difference at all.
The motor spins freely and smoothly between my fingers, it’s now got a new impeller and pump housing and a new motor capacitor. The upper bar still refuses to spin.I removed the upper bar from it’s mount and noticed the thin rubber washer around the locking ring was looking rather stretched and distorted, then I noticed the transparent plastic bush that acts as a bearing between the arm itself and the central spigot, was split. I’m guessing a new upper spray bar is needed now. 🙁
Meantime, I’ve managed to get it to rotate slowly by blocking four of the inner jets with self tapping screws. At least it goes round now.
- You must be logged in to reply to this topic.