Condensation or Leak on Central Heating Pipework?

paperclap

Hi all,

So I’ve recently redone the central heating pipework in our house.

However, this particular section, I didn’t do.

Now, at the top of this right pipe was full of water. Looked like condensation, as the water was all around the pipe - not in a singe area. From that, there was a small bead of water trickling from the top of the pipe all the way to the bottom.

Joints look fine as far as I can see. Pressure hasn’t dropped. Though, could be a small trickle over a large portion of time which might go unnoticeable.

However, I go into the loft, and one small 6 inch section of pipe wasn’t lagged. The 6 inch section was of course the same pipe (in loft, above right pipe in photo). It was incredibly cold here last night. We had the heating on for a couple of hours. Next morning (today), condensation on windows.

These pipes are also on an external wall.

Could this be condensation forming on the pipe and trickling down?

That 6 inch section of pipe felt dry though. Though, could have dried out due to lots of airflow in the loft space?

Thanks.

Bendy_House

laurencewhymark said:

Hi all,

So I’ve recently redone the central heating pipework in our house.

However, this particular section, I didn’t do.

Now, at the top of this right pipe was full of water. Looked like condensation, as the water was all around the pipe - not in a singe area. From that, there was a small bead of water trickling from the top of the pipe all the way to the bottom.

Joints look fine as far as I can see. Pressure hasn’t dropped. Though, could be a small trickle over a large portion of time which might go unnoticeable.

However, I go into the loft, and one small 6 inch section of pipe wasn’t lagged. The 6 inch section was of course the same pipe (in loft, above right pipe in photo). It was incredibly cold here last night. We had the heating on for a couple of hours. Next morning (today), condensation on windows.

These pipes are also on an external wall.

Could this be condensation forming on the pipe and trickling down?

That 6 inch section of pipe felt dry though. Though, could have dried out due to lots of airflow in the loft space?

Thanks.

The water that was all the way around the pipe, was it in tiny droplets, as if sprayed on? If so, almost certainly condensation.

Which would be no great surprise since you've also had this on the windows following the cold night. This pipe will also be one of the coldest surfaces in the room, and up near the ceiling the room air will be at its warmest and moistest. And I presume there will be a steady air flow going up that hole, bathing that pipe in wetnessess.

paperclap

Bendy_House said:

laurencewhymark said:

Hi all,

So I’ve recently redone the central heating pipework in our house.

However, this particular section, I didn’t do.

Now, at the top of this right pipe was full of water. Looked like condensation, as the water was all around the pipe - not in a singe area. From that, there was a small bead of water trickling from the top of the pipe all the way to the bottom.

Joints look fine as far as I can see. Pressure hasn’t dropped. Though, could be a small trickle over a large portion of time which might go unnoticeable.

However, I go into the loft, and one small 6 inch section of pipe wasn’t lagged. The 6 inch section was of course the same pipe (in loft, above right pipe in photo). It was incredibly cold here last night. We had the heating on for a couple of hours. Next morning (today), condensation on windows.

These pipes are also on an external wall.

Could this be condensation forming on the pipe and trickling down?

That 6 inch section of pipe felt dry though. Though, could have dried out due to lots of airflow in the loft space?

Thanks.

The water that was all the way around the pipe, was it in tiny droplets, as if sprayed on? If so, almost certainly condensation.

Which would be no great surprise since you've also had this on the windows following the cold night. This pipe will also be one of the coldest surfaces in the room, and up near the ceiling the room air will be at its warmest and moistest. And I presume there will be a steady air flow going up that hole, bathing that pipe in wetnessess.

Exactly that Bendy_House. At the top, the water was like droplets like it'd been sprayed on.

I've wiped down the moisture. Whacked the heating on for a couple hours, and couldn't see any signs of leaks... and again, the pressure remains the same.

Will nip to Toolstation to get some insulation this evening and pop it on.

Though, this does beg the question whether the pipework (that'll eventually be boxed in), should this be insulated somehow? Given that there is a gaping hole directly above, leading to the cold loft space. Alternatively, I fill that hole with something, say spray foam or some plaster.

Eldi_Dos

I would go for fire stopping compound ( not fire stopping sealant) in that location as when boxed in it will be like a chimney.

Bendy_House

laurencewhymark said:

Exactly that Bendy_House. At the top, the water was like droplets like it'd been sprayed on.

I've wiped down the moisture. Whacked the heating on for a couple hours, and couldn't see any signs of leaks... and again, the pressure remains the same.

Will nip to Toolstation to get some insulation this evening and pop it on.

Though, this does beg the question whether the pipework (that'll eventually be boxed in), should this be insulated somehow? Given that there is a gaping hole directly above, leading to the cold loft space. Alternatively, I fill that hole with something, say spray foam or some plaster.

Cool - almost certain, then.

Personally, I'd just completely block that hole, with foam or similar. (Firestop if you want, but the risk must be infinitesimal). I doubt I'd bother insulating the pipes before boxing in, as the heat ain't going anywhere. Then again, perhaps you don't want the boxing to be expanding and contracting, so a layer of loft insulation or similar lining the boxing might be a good call. It'll also likely cut down on any noise the pipes might make.

Important thing, tho' - it doesn't seem like a leak :-)

paperclap

Thanks Bendy_House!

Lagged the little length of pipe above, in the loft space.

This morning, still a little condensation on the top portion of pipes… so I think what I’ll do is use some thermal spiral wrap to insulate these pipes.

Bendy_House

I think I'd go for an easy option - use a spray foam to first block that hole completely, then I'd be tempted to run a bead down between the pipes, and certainly covering them fully near the top section at least. If it expands too much, it can be trimmed to allow the boxing to go over it.

jaizan

If it's condensation, it will only be evident when the pipes are properly cold.    Which is easily tested when you can run the heating at a low level.

If it is leaking, the leak will probably be from a joint, so check the joints above this section.

The only time I see condensation on pipes is the cold water feed to things like the toilet and sink in the bathroom.   Where very cold water enters a humid room.

In your case, if those pipes go into the loft, I would be far more worried about the prospect of the pipes in the loft freezing and bursting.  You should only get condensation if the pipes are colder than the air and the walls in the room.   Which would imply cold is conducted down from the loft.

  Do you have the thickest possible pipe insulation securely fitted around the entire length of the pipes in the loft ?

jaizan

If it's condensation, it will only be evident when the pipes are properly cold.    Which is easily tested when you can run the heating at a low level and there should then be no water.

If it is leaking, the leak will probably be from a joint, so check the joints above this section.

The only time I see condensation on pipes is the cold water feed to things like the toilet and sink in the bathroom.   Where very cold water enters a humid room.

In your case, if those pipes go into the loft, I would be far more worried about the prospect of the pipes in the loft freezing and bursting.  You should only get condensation if the pipes are colder than the air and the walls in the room.   Which would imply cold is conducted down from the loft.

  Do you have the thickest possible pipe insulation securely fitted around the entire length of the pipes in the loft ?

I have temperature sensors in my loft and at night in the winter, the airspace gets down to something similar to external temperatures, which can be below freezing.

Eldi_Dos

Bendy_House said:

laurencewhymark said:

Exactly that Bendy_House. At the top, the water was like droplets like it'd been sprayed on.

I've wiped down the moisture. Whacked the heating on for a couple hours, and couldn't see any signs of leaks... and again, the pressure remains the same.

Will nip to Toolstation to get some insulation this evening and pop it on.

Though, this does beg the question whether the pipework (that'll eventually be boxed in), should this be insulated somehow? Given that there is a gaping hole directly above, leading to the cold loft space. Alternatively, I fill that hole with something, say spray foam or some plaster.

Cool - almost certain, then.

Personally, I'd just completely block that hole, with foam or similar. (Firestop if you want, but the risk must be infinitesimal). I doubt I'd bother insulating the pipes before boxing in, as the heat ain't going anywhere. Then again, perhaps you don't want the boxing to be expanding and contracting, so a layer of loft insulation or similar lining the boxing might be a good call. It'll also likely cut down on any noise the pipes might make.

Important thing, tho' - it doesn't seem like a leak :-)

It is just as easy to use compound in situation like in photo and can achieve a better cosmetic finish.The only difficulty the average diy'r would have is sourcing small enough quantities for domestic use. I prefer tubes if you can get them.
Do not think it is to far in the future where it will become a requirement in LA/HA/ domestic properties, best to get ahead of future requirements.