[Gillespie]

It’s a relatively new system circa 4 years old, it was fitted when we did our extension and the end guest bedroom needs bleeding regularly, there’s no leaks or anything and it’s only this one, seems bizarre, any ideas?

[Sennen]

I bet its bleeding annoying.

[robbiep]

If it's at the end of the run, or at the highest point on the system, then that is where all the air in the system will end up.

Basic physics really

[Tengocity]

"I don't have time to bleed"

One of the best lines from one of the best movies of all time!

[Gillespie]

Originally Posted by robbiep

If it's at the end of the run, or at the highest point on the system, then that is where all the air in the system will end up.

Basic physics really

It is the end one but I’ve never had this problem before, I’ll get somebody out.

[HighlandPete]

Originally Posted by Gillespie

It is the end one but I’ve never had this problem before, I’ll get somebody out.

Are you running with an inhibitor, to help prevent sludge and corrosion?

'Air' (hydrogen) can be generated due to corrosion and oxidisation.

[Gillespie]

Originally Posted by HighlandPete

Are you running with an inhibitor, to help prevent sludge and corrosion?

'Air' (hydrogen) can be generated due to corrosion and oxidisation.

Yes I am.

[G50]

Is it the fiesta driving footballers bedroom?

[Gillespie]

Originally Posted by G50

Is it the fiesta driving footballers bedroom?

Yes

[G50]

Originally Posted by Gillespie

Yes

Ahh, all is right with the [forum] world once again!

[JustChris]

We've a radiator like this too. annoyingly it's the one in our bedroom. Seems to only take a few weeks before it needs bleeding again.

It's bubbly as F on full heating, barley need an alarm in the morning.

[Ronstein]

Originally Posted by robbiep

If it's at the end of the run, or at the highest point on the system, then that is where all the air in the system will end up.

Basic physics really

This ^

[Harryg]

Had the same problem with a leak driving me barmy went at it and eventually found it was a seal on a union, cleaned area renewed seal and no more problems.
Al I got off the better half was seems fitting a turnip looking for a leak.

[Watsey]

If it's a sealed system for heating and hot water you could also check whether it's sufficiently pressurised. Being well into the operating pressure range will help to reduce the likelihood of vapour forming in the boiler heat exchanger and remaining in the circulation system - higher pressure increases the boiling point of water. If the pressure dial on the boiler is indicating towards the low end of the range you can use the top-up circuit from the mains supply to increase the pressure.

Expansion vessels, normally an inflatable bladder in a rigid housing (often integral to the boiler), do leak air into the system over time. Just one of those things. I know how to inflate mine, but it's one of those things that a heating engineer would check/correct as part of a service.

[ZedsRedBaby]

Originally Posted by HighlandPete

Are you running with an inhibitor, to help prevent sludge and corrosion?

'Air' (hydrogen) can be generated due to corrosion and oxidisation.

The easiest way to check for this is to hold a match or lighter to the vent when you bleed it. If it burns or pops, it's hydrogen generated by corrosion, if not it's just air in the system.

[jenshb]

Be very careful holding open flame to a source of hydrogen. Hydrogen gas and air is a rather explosive mixture.

[ZedsRedBaby]

Originally Posted by jenshb

Be very careful holding open flame to a source of hydrogen. Hydrogen gas and air is a rather explosive mixture.

Don't worry, the amount that comes out of a radiator won't blow your roof off

[EvilDrPorkChop]

A good system once settled down shouldn't get Air in - maybe a tiny bit but if it's continuous and a fair bit then there's an issue. Mine at home gets very little in.

If it's a sealed system - which seeming it sounds fairly new then you've probably got a very small water loss somewhere or corrosion (Or in some very rare cases, plastic pipe without the barrier in it which absorbs oxygen - from about 20 year ago). How often are you topping your pressure up?

If it's Open Vented (Where you have a small header tank in the loft) then there's the possibility it's drawing Air in through the Vent.

Hope that helps.
Resident Bimmerpost Plumber

[Gillespie]

Originally Posted by EvilDrPorkChop

A good system once settled down shouldn't get Air in - maybe a tiny bit but if it's continuous and a fair bit then there's an issue. Mine at home gets very little in.

If it's a sealed system - which seeming it sounds fairly new then you've probably got a very small water loss somewhere or corrosion (Or in some very rare cases, plastic pipe without the barrier in it which absorbs oxygen - from about 20 year ago). How often are you topping your pressure up?

If it's Open Vented (Where you have a small header tank in the loft) then there's the possibility it's drawing Air in through the Vent.

Hope that helps.
Resident Bimmerpost Plumber

Could it be that it’s a new system coupled to an old pipe network, we have solid floors so to replace the whole system would have meant digging it all up? The old part is steel imperial pipes.

[Goneinsixtyseconds]

Originally Posted by Gillespie

Could it be that it’s a new system coupled to an old pipe network, we have solid floors so to replace the whole system would have meant digging it all up? The old part is steel imperial pipes.

Mine was doing this for ages, combined with a pressure top up every 6 weeks or so.

About two weeks ago the pressure started dropping every 12 hours. The most obvious sign at the boiler was not present, so worried it was a leak somewhere under the floor, as nothing obvious anywhere else.

Short version of story, turned out it was a cracked heat exchanger in the boiler, which luckily for me was still under warranty. 3 moths left of 7 years. He also said expansion vessel was flat and replaced that. Zero pressure loss and no radiator bleeding since it was done.

[EvilDrPorkChop]

Originally Posted by Gillespie

Could it be that it’s a new system coupled to an old pipe network, we have solid floors so to replace the whole system would have meant digging it all up? The old part is steel imperial pipes.

That's probably your issue then. Sure you've get Steel connected onto your new system? More than likely some corrosion going on. How often are you topping up the pressure?

Certainly something i'd of been replacing.

[JR1664]

Originally Posted by Gillespie

Could it be that it’s a new system coupled to an old pipe network, we have solid floors so to replace the whole system would have meant digging it all up? The old part is steel imperial pipes.

Father in law had similar. A combi on an old system but fortunately the leak was under floorboards.

You'll eventually find out if you have a leak under solid flooring ..in the next few years, so suggest you check your insurance as it ain't pretty.