Water from boiler overflow pipe

johnnyren

 Hi all
          I put a thread on about a month ago regarding a strange drone noise that came on randomly if I was using the hot water,      It’s still the same and my plan was next week to get a plumber out to have a look and do a boiler service as well.
so today while I was out I noticed water has been coming out randomly from a copper overflow pipe at the side / gable end of my flat ,      What does this mean ?   I’ll have the plumber out definitely  no later than Monday ,      Is there a worst case scenario or something that can be taken care of with the service ?  

 Thanks for any help 

WIAWSNB

What do you mean by 'randomly'?

johnnyren

It’s not coming out constantly ,    Is coming ln a randomly ,      I don’t know it’s when maybe a bath is being run or the washing machine being used 

MeteredOut

I doubt its random.

Is the copper pipe and outflow from the boiler. ie is the boiler the other side of the wall from the pipe? If not, what is there - can you check the other side of the wall? Attic?

You said the boiler was making a noise when running the hot water. Does the water only appear when running the hot water?

What make/model of boiler do you have? Do you have a water tank?

It sounds like it could be some sort of pressure relief outlet.

johnnyren

MeteredOut said:

I doubt its random.

Is the copper pipe and outflow from the boiler. ie is the boiler the other side of the wall from the pipe? If not, what is there - can you check the other side of the wall? Attic?

You said the boiler was making a noise when running the hot water. Does the water only appear when running the hot water?

What make/model of boiler do you have? Do you have a water tank?

It sounds like it could be some sort of pressure relief outlet.

MeteredOut said:

I doubt its random.

Is the copper pipe and outflow from the boiler. ie is the boiler the other side of the wall from the pipe? If not, what is there - can you check the other side of the wall? Attic?

You said the boiler was making a noise when running the hot water. Does the water only appear when running the hot water?

What make/model of boiler do you have? Do you have a water tank?

It sounds like it could be some sort of pressure 

The pipe is part of the pipework coming from the bottom of the vokera combi boiler ,     I goes right out to the rear through the wall to the outside ,   To me it certainly seems like an overflow pipe,      We do have a water tank up in the main loft of the communal flat building 
I don’t think that has anything to do with this pipe ,     It’s definitely from the boiler 
I’ve not checked as to when the water flows from it yet ,    

grumpy_codger

It's 'pressure relief', not 'overflow'. If water leaks from this pipe this has to result in pressure dropping in the sealed CH system. This is usually caused by faulty expansion vessel of the boiler (or faulty pressure relief valve).

johnnyren

grumpy_codger said:

It's 'pressure relief', not 'overflow'. If water leaks from this pipe this has to result in pressure dropping in the sealed CH system. This is usually caused by faulty expansion vessel of the boiler (or faulty pressure relief valve).

I am running a bath at present and there is now water coming from the pressure relief pipe 

WIAWSNB

And what does the boiler pressure gauge read?
And how does that compare with when the boiler is off and cool?
It does sound like wot Grumpy said.

Heedtheadvice

Condensate draining pipe?

JohnB47

grumpy_codger said:

It's 'pressure relief', not 'overflow'. If water leaks from this pipe this has to result in pressure dropping in the sealed CH system. This is usually caused by faulty expansion vessel of the boiler (or faulty pressure relief valve).

Not necessarily faulty. It could be that it simply needs repressurised and therefore it is not able to take up the pressure generated by the CH water being heated.

As already asked, what is the system pressure reading hot/cold?

Could it be that the dripping pipe is actually the waste condenser water pipe? It's perfectly normal for that to drip at any point  - hot water being run or CH running. The condenser pipe on my system is white plastic and is internal, connected to the waste under the kitchen sink.

johnnyren

JohnB47 said:

grumpy_codger said:

It's 'pressure relief', not 'overflow'. If water leaks from this pipe this has to result in pressure dropping in the sealed CH system. This is usually caused by faulty expansion vessel of the boiler (or faulty pressure relief valve).

Not necessarily faulty. It could be that it simply needs repressurised and therefore it is not able to take up the pressure generated by the CH water being heated.

As already asked, what is the system pressure reading hot/cold?

Could it be that the dripping pipe is actually the waste condenser water pipe? It's perfectly normal for that to drip at any point  - hot water being run or CH running. The condenser pipe on my system is white plastic and is internal, connected to the waste under the kitchen sink.

The pressure at present is hot and is sitting just below 2,      It’s not something i check but play partner says in the morning it’s just over 1.5 

the pipe comes down about 6 inches from the bottom of the boiler then goes out behind and out through a drilled hole at the gable end of the building