[AndyByTheSea]

“helo_75” wrote:oh, and the dryer voltage is supposed to be 240v, it doesnt vary… why or how would it, its simply switched on and off

From AndyByTheSea.
Thank you to all of the above who have commented to date.

For clarification.

The “one flash” or f1 fault code doesn’t (on my faulty machine) occur until the drying cycle has been running for several minutes. (It can be as long as 30minuutes)

To verify that I wasn’t kidding myself, I ran the dryer from cold and after a minute I disconnected the thermistor while the power was on. A “one flash” fault code develops with in a few seconds.

I isolated the supply reconnected the thermistor reset the programme knob and switched the machine on to the drying cycle. It ran satisfactorily for a further 3 minutes when I repeated the above, with the same result, I switched it off but I have no doubt that it would have gone on running until the thermistor reached its over temperature condition. (I did this twice so I can assure everyone that my comments in posting of Monday Dec 08 2008 3:14pm are based on fact not opinion)

Consequently in answer to helo_75’s posting (Mon Dec 08, 2008 7:45) the f1 code was not per existing. The condition develops each time from cold.

I’ve had a meter across the heater element and the power to the element stays on all the time until eventually the thermistor kicks in (goes O/C) and the f1 code is announced.

Question. 1)
From the comments made it’s been suggested that the triac is used as an “on/ off” device. If it’s not used in phase angle firing mode is it used as a burst firing control (being controlled by the thermistor) or is the element driven constantly at the full ~1.3kw until the end of the cycle?

Question. 2)
Is there a relay (or programme switch function) that isolates the heater element or are there only semiconductors between the element and the mains supply?

The reason for question 1) is, if it is a burst firing control circuit, then I’m not seeing the controlled pulses at the element.

If the answer to question 2) is “no” there are no relays that would confirm that the triac is functioning as the voltage is isolated when the fault occurs. It could still mean of course that some part of the control function is faulty.

The answers are probably academic as I’m not about to build a test bed of thee PCB and the idea of trying to work on my knees with an oscilloscope connected to a PCB flapping about on the impossibly short wires doesn’t appeal.
I have still not completely ruled out the idea that there is simply not enough air rushing past the element to keep the thermistor down to a safe working temperature. The airways are clear now and I can see the fan is running but I can’t establish just how much air is moving. The fan its self is clean and all of its blades are there and it spins freely when turned.

I don’t mind a challenge but I’d be happier if the machine was properly dead rather than this “dries for 30 minutes nonsense.” A nice big holes burnt in the middle of the PCB would be pretty convincing.

I’m sure it will come down to a module fault but it grieves me to have to pay ~£100
To replace what is no doubt a tuppeny component.

I’d be interested to hear from anyone that can give a factual answer the questions.

Good luck and keep on fixing them!

Regards Andy.

[AndyByTheSea]

Re: Problem with error code 1 on Ariston Margherita 2000 w/m

Hi. Well I thought I’d fixt it. But I have come to the conclusion that it’s going to be the PCP.

But here are some tips for other suffers of a “one flash fault”
I have established that the “single flash” or “code one” fault can be induced by disconnecting the thermistor that’s associated with the dryer element.

On my machine the thermistor cold resistance is around 39 Ohms going to infinity when it goes over temperature. With this in mind I guess if the fan stopped it would cause a code one fault. (There’s a small spouted hole about 6mm diameter about 25mm away from the motor, towards the back of the machine, and you can see if the motor is turning through it.)

Likewise if the thermistor were faulty (high resistance) it would give a code one indication as would anything that restricted the airflow by allowing the dryer element to overheat.
I found that the condenser (the plastic tube that connects the back of the drum to the bottom of the fan) on my machine was substantially blocked with fluff, there’s a stainless steel disc about 75mm in diameter in the condenser where it meets the back of the drum, mine was totally blocked with soap powder and wet fluff.

To get it off you have to remove the M8 bolt that holds the back of the fan assembly casing down and slacken off the two M13 bolt that hold down the front of the assembly. The fan casing lifts out of the way, you’ll need to unclip the cold water feed to the condenser and undo the clip that holds the lower end of the condenser to the drum. (I took the main drum pulley off but I don’t think I actually needed to, it was hard to undo the holding bolt as it has a thread locking solution on it.)

After cleaning out at least half a cupful of sodden fluff from the airway in the condenser and unblocking every hole in the disc I was convinced I most have improved the situation but on re assembly I found I still had the same fault, i.e. code one. The thermistor went to infinite resistance after a very short time (and the body of the casing was very hot) With a meter across the element I saw that the voltage was a full 240 volts. I assume that a semiconductor is used to control the heat output and that this function isn’t working on my machine as I was anticipating that the voltage (and the temperature) would be controlled to some “safe” level.

I’ve had the PCB out and all three legged devices seen OK and I guess the next thing is to substitute the board. I’m assuming that even washing machine manufacturers don’t rely on a semiconductor as a safety override and the open circuit thermistor is seen by a relay?

So still not fixed yet but out of interest:
The fan motor is working OK and its DC resistance is 44ohms.
The thermistor’s cold resistance ~39 ohms going high with temp to infinity when overheated.
The dryer heater element resistance is 42 ohms, i.e OK.

I hope this helps somebody as I’m sure that the clogged condenser or dead fan are possible causes for a code one fault.

Kind Regards Andy.

[AndyByTheSea]

Re: Problem with error code 1 on Ariston Margherita 2000 w/m

Thanks again for the comments Jim,

I’m going to have to leave it for a little while before I will have the time to sort it out, luckily I have a brass rail over a very reliable wood burner, it can dry a bath towel in about an hour and there’s not a semiconductor in site.

Once I get it sorted I’ll post the result.

I see that you’ll soon be at the ten thousand mark for postings, that’s a lot of effort, thanks for coming back to me.

Regards Andy.

[AndyByTheSea]

Re: Problem with error code 1 on Ariston Margherita 2000 w/m

Thanks Jim, I appreciate your comments.

I’m having a problem coming to terms with the idea of the problem being a faulty triac as this problem has developed i.e. I used to have the problem of the programme knob continually turning but I could “reset” it and the machine would recover and carry on running the drying cycle.

I can’t for certain say what code the flashing indicating was giving at that time. The fault condition has become more frequent until now the problem is always there and the indicator is, as I said before flashing once. I would expect a triode to stay dead once it fails.

I have seen that on some dryers (mine’s a washer/dryer) that a code one indication is related to “Not sufficiently dry to continue” or words to that effect. Such a fault might suggest a “developing condition” or maybe a sensor drifting or something like that.

Regards Andy.

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