Glow worm 24cxi F9 fault

[hogger]

Hi guys

Rude for my first post to be a question but the house is freezing and the Mrs is angry so needs must!
As the title says....

Had the F9 fault earlier this year and managed to solve it with a new thermistor.
Now it is back again,

manual states;
possibly thermistor (guessing its unlikely as replaced one already),
possibly main pcb (god I hope not as they seem pricey)
possibly pressure sensor..... tried this first as it seemed to be the most common reason online for a F9 fault, but didnt make any difference, however.... and this is where I am looking for help please guys!

The manual states part should be glow worm number 2000801901, the part the local boiler spares shop has given me is also glow worm but part number 0020079644 but they reckon its for the cxi/sxi range as they are interchangeable......

Can anyone tell me if this is true or if they have any experience of this?

I dont really want to spend a fortune on a new pcb etc just to find it was the wrong sensor!

 

[Agile]

This is why diagnosing faults is so important to avoid buying expencive parts which are not required.

Everything except the PCB can be individually tested !

Tony

 

[hogger]

Thanks
I agree, and in your opinion can the two glow worm cxi pressure sensors be interchanged?

 

[Agile]

An opinion is a subjective assesment. You need a definitive statement.

I dont know about those sensors.

But the original pink Vaillant one has now been replaced by a black one.

But I dont blindly change parts and would be testing a sensor if I thought it was faulty.

Tony

 

[hogger]

Fair enough and thanks for replying.

If anyone else could shed some light on this please do.... any help opinions would be VERY appreciated.

 

[compheat]

I had the same fault on a Halstead Eden Cxi and it was cured by changing the pressure sensor.

 

[mickyg]

yeh that will work fine. all the vaillant, glowworm, sd, jaguar and protherm pressure sensors are all interchangeable

 

[misterdubya]

F9 can mean anything on the low voltage side.

 

[hogger]

Thanks Guys

At least by knowing the sensor is interchangable I know its not the pressure sensor now.

Ive read in a few places that the F9 can mean a whole heap of things! Grr!
Well someone on fleabay is selling the thermisters at less than half price so Ive ordered a couple of those to try in case its the same problem again.

Thanks again for the help and conformation

 

[mickyg]

i might have some parts to sell if you want them. I'll go check out my store tomorrow might be perfect opportunity to have a clear out

 

[hogger]

Cheers Micky
May well chase you up on that offer, time to get the 4 hotwater bottles ready for bed now!

 

[Agile]

yeh that will work fine. all the vaillant, glowworm, sd, jaguar and protherm pressure sensors are all interchangeable

The pink press sensor used earlier in the Vaillants was also used in the Viessmanns as well.

Tony

 

[hogger]

Well I have hot water and central heating again!
Yippee!

Changed both the thermisters when they arrived this morning and hey presto!

Now it was my understanding that thermisters were hardy little things that hardly went wrong, so.... as I had an F9 about 6months ago and it turned out to be one of these little blighters is it normal for it to fail so soon or is it likely to be something else triggering it? (Though for the life of me I cant think what!)

Cheers again to all who helped esp Micky for the sensor confirmation

 

[Agile]

It is not normal for any part to fail often.

If you are buying cheap parts on ebay then many are copy parts and not the original types.

.

Tony

 

[hogger]

GRRRRRRRR!!!!!!!!!!

Well the house was lovely and warm for just over 2hours then F4 fault appeared, I wasnt too worried as it had done this once before 2yrs ago when I had a high demand (CH on full and HW filling a bath) so as before switched off and then on again........ only to be faced with no display?????
Checked the manual and it says too check the wiring between the display and main pcb, I have done this even though it hasnt been touched. No joy!

Any ideas anyone?

And yes Tony unfortunately I had bought from ebay so maybe your suspicion is quite correct.