Vaillant boiler not heating water

[Agile]

Working order maybe, but is it working?

What is his experience level? Could he identify if the pump is indeed spinning?

You can listen to a pump with a mechanical stethoscope or simple listening stick.

They buzz/hum at 100 Hz if seized up or rumble/hiss if turning.

Tony

 

[DP]

They buzz/hum at 100 Hz if seized up or rumble/hiss if turning

Hummmm, 100 hertz. Learning every day, not

 

[bambibasher]

Bring back puller and steel is all i can say

 

[AGAS]

Agile how the fook would she/he know it would be 100 HZ and why would they ?? are you trying to make yourself sound clever ?

 

[DP]

Unless I have gone completely bonkers, hum would be 50 hertz hum surely, it is 50 cylcles per second in old money, 60 if one is states side, three 50 hertz waves 120 degrees displaced on a three phase, put 50 hertz through a bridge rectifier, 100 pulses etc

 

[The831Bunny]

This boiler would fire if the pump was stuck, then show an overheat code. Sounds very much like you need a Gas Safe engineer conversant in Vaillant appliances to check the boiler properly. If not Vaillant themselves do a fixed price repair which includes up to three parts.

 

[Agile]

Unless I have gone completely bonkers, hum would be 50 hertz hum surely, it is 50 cylcles per second in old money, 60 if one is states side, three 50 hertz waves 120 degrees displaced on a three phase, put 50 hertz through a bridge rectifier, 100 pulses etc

Indeed the supply is at 50 Hz.

However, in a full cycle you have one positive and one negative excursion. So two potential magnetic pulses per cycle and thus 100 per second.

In a pump the hum is caused by each half wave pulse regardless of if it is negative or positive. Hence the hum is heard at 100 Hz.

 

[JohnD]

here is 50hz hum

here is 100hz hum

and for our American members, here is 60hz hum

edit
Looking at Agile's post, I don't know, when you listen to, say, the string of a double Bass vibrating at 50Hz in an approximation of a sine wave, if your eardrum receives 50 or 100 impacts per second. I assume 100. We count Hz as the number of peaks, we don't count both the peaks and the troughs

(who knows this stuff? haven't thought about it for years)

 

[DP]

Thank you JohnD

Hertz is same as cycles per second. Regardless of two bumps per cycle, there is NO WAY 50 Hz wave can be called 100 Hz

 

[Agile]

You seem to be missing the point.

When you are listening to a sound produced by a magnetic field you get two pulses per cycle when it is the effect of the strength and not the polarity of the field.

 

[AGAS]

Hence the hum is heard at 100 Hz.

 

[seniorservice]

All this talk of 'sine'. Wrong boiler.

 

[DP]

You seem to be missing the point.

When you are listening to a sound produced by a magnetic field you get two pulses per cycle when it is the effect of the strength and not the polarity of the field.

Whatever, but no way is it 100 hertz. 1 full hertz has a positive and negative trace, so 50 hertz can never be 100 hertz.

 

[AGAS]

Whatever, but no way is it 100 hertz. I full hertz has a positive and negative trace, so 50 hertz can never be 100 hertz.

back tracking and splitting hairs comes to mind ,

 

[Pipzi92]

Okay so quite a few posts about hertz...
Had a gas safe engineer come out and he found out it was the fan! So all replaced and now we have hot water and heating! Yay!