Vaillant VCW 242 Water too hot!!

[paddy69]

Hi!
Can anyone point me in the right direction for what to look at?
My Vaillant VCW 242 is driving my wife nuts (she is the one who likes hours under the shower) The shower has got to the point where you have to really back off the hot water (mixer shower) a lot to have it cool enough to stand under and then it goes too cold. I have noticed that the bath water is also coming out extremely hot. It never used to do this!
The only thing I have noticed with the boiler recently is that there is a slight electrical hum coming from it even when off. This may be completely unrelated!
Does it sound like a circuit board or maybe just a stat in the line gone wrong???
Cheers!
Phil

 

[Agile]

What position is the hot water temperture knob on the boiler?

 

[paddy69]

Hi! Agile.
The hot water dial is turned fully to get least flow and most hot water, if you know what I mean
Phil

 

[paddy69]

Agile,
Will the NTC sensor, if it's dodgy, cause the flame to not modulate downwards?? The flame most definitely modulates upwards when I start the boiler but not sure if it is modulating back. I am wondering if this is why her showers go cold? She has to keep adding cold as the hot water temp goes up and up and it gets to the point where the slow flow and heat in the boiler cause an overheat cutoff. She is then whacking the hot water back up that fires the boiler up again! Probably need to be by the boiler while she has one of her showers!
Phil

 

[Agile]

I asked about the boiler !

You seem to have replied about the shower !

You also have set it to the hottest position and then complain its too hot !

Why not turn it back to make it cooler ?

Or do I have some serious comprehension problem?

Tony

 

[paddy69]

Hey, something has changed with the boiler!
I have done NOTHING to the boiler!
You used to start the shower off by putting in on full hot (Hot water comes from the BOILER) and when the hot had stabilised you would then back the shower off (adding a bit of cold) to make a comfortable temp (sometimes you did have to add a little more cold after being in 10 mins)
Now, after having done NOTHING to the boiler, you jump in the shower, it gets too hot, you add more cold, it gets too hot still, you add more cold etc etc etc, until it goes cold!
I have baths and have noticed the hot water coming a lot hotter than it used to. MUST be a boiler issue!!!!!!
I am just looking at the boiler now and it would appear that the flame is not modulating back!!!
Phil

 

[Agile]

I asked about the boiler !

You seem to have replied about the shower !

You also have set it to the hottest position and then complain its too hot !

Why not turn it back to make it cooler ?

Or do I have some serious comprehension problem?

Tony