Why does this radiator need bleeding regularly?

EvilDrPorkChop · 02-23-2018, 06:27 AM

Quote:

Originally Posted by MarkG_M3CP

I need to get my system sorted (balanced I think) as some radiators started gurgling.

I keep bleeding them and little bits of air come out but it's a vented system so I think the air just sits in places due to the low pressure. That and the rads are fed by a manifold and 10mm microbore.

Pain in the arse but generally works so well there's little point in updating.

Anyone know the effect of pump speed on such a system? I'm thinking of tuning up to 3 to bleed but suspect this also may increase chances of noise/burbling.

We have added a rad and replaced a couple of old singles with doubles. But then I've also removed one in the kitchen too....

:

Increasing your pump speed on a vented system can cause it to pump over and draw in more air. If it's been set on 2 it's usually for a reason.

EvilDrPorkChop · 02-23-2018, 06:28 AM

Quote:

Originally Posted by dbramley

Ours is a new build and a vented system...

Its normal to have some radiators switched partly off, its how you balance the system. If you dont do that youll end up with all the heat going to the wrong places.

If it's new build within the last 7 years you'll have a Unvented system.

EvilDrPorkChop · 02-23-2018, 06:30 AM

Quote:

Originally Posted by Sasquartch

Quote:

Originally Posted by JLR1969

To get 1 bar you would need to have the tank about 80ft in the air

Think it's closer to 30 feet, approx 10m iirc

Yeah 1 bar for every 10m head.

Watsey · 02-23-2018, 06:50 AM

Quote:

Originally Posted by Sasquartch

Quote:

Originally Posted by JLR1969

To get 1 bar you would need to have the tank about 80ft in the air

Think it's closer to 30 feet, approx 10m iirc

Correct.

Watsey · 02-23-2018, 06:56 AM

Quote:

Originally Posted by MarkG_M3CP

I need to get my system sorted (balanced I think) as some radiators started gurgling.

I keep bleeding them and little bits of air come out but it's a vented system so I think the air just sits in places due to the low pressure. That and the rads are fed by a manifold and 10mm microbore.

Pain in the arse but generally works so well there's little point in updating.

Anyone know the effect of pump speed on such a system? I'm thinking of tuning up to 3 to bleed but suspect this also may increase chances of noise/burbling.

We have added a rad and replaced a couple of old singles with doubles. But then I've also removed one in the kitchen too....

:

It's unlikely that a vented system is drawing-in air. More likely that vapour in the system is a result of the boiler 'kettling' ie water is boiling in the heat exchanger due to a relative lack of pressure in the system. The boiling point of water is not a constant - lower pressure exerted on it reduces the boiling point.

Not much you can realistically do about it with a vented system. Just make sure you bleed the rads regularly. The rads sky act as a gas trap, which tends to stop air circulating around the system.

As mentioned, I also wouldn't increase the pump speed.

JLR1969 · 02-23-2018, 08:13 AM

Quote:

Originally Posted by Sasquartch

Think it's closer to 30 feet, approx 10m iirc

It wasn't an exact science comment on my part more that it would need to be high.

I also would expect the more rads the higher the tank....

Alscoob · 02-23-2018, 08:34 AM

The man needs a proper plumber / heating engineer as everything here is speculation !

F20MAW73 · 02-23-2018, 11:24 AM

Quote:

Originally Posted by Alscoob

The man needs a proper plumber / heating engineer as everything here is speculation !

The 'mans not hot'

F20MAW73 · 02-23-2018, 11:34 AM

You could try replacing your manual radiator vents with Aladin auto air vents. Have fitted these before and they are are quite effective.

http://aladdin-products.co.uk/products/autovents/

Also is the heating system water clean or dirty/perhaps full of magnitude sludge as this can cause poor circulation issuse and aerated water. If so the sysyem may need a decent chemical power flush and dose on completion with suitable corrosion inhibitor.

JLR1969 · 02-23-2018, 01:22 PM

Quote:

Originally Posted by F20MAW73

The 'mans not hot'

Never hot.

MarkG_M5Comp · 02-23-2018, 02:45 PM

Quote:

Originally Posted by Watsey

Quote:

Originally Posted by MarkG_M3CP

I need to get my system sorted (balanced I think) as some radiators started gurgling.

I keep bleeding them and little bits of air come out but it's a vented system so I think the air just sits in places due to the low pressure. That and the rads are fed by a manifold and 10mm microbore.

Pain in the arse but generally works so well there's little point in updating.

Anyone know the effect of pump speed on such a system? I'm thinking of tuning up to 3 to bleed but suspect this also may increase chances of noise/burbling.

We have added a rad and replaced a couple of old singles with doubles. But then I've also removed one in the kitchen too....

:

It's unlikely that a vented system is drawing-in air. More likely that vapour in the system is a result of the boiler 'kettling' ie water is boiling in the heat exchanger due to a relative lack of pressure in the system. The boiling point of water is not a constant - lower pressure exerted on it reduces the boiling point.

Not much you can realistically do about it with a vented system. Just make sure you bleed the rads regularly. The rads sky act as a gas trap, which tends to stop air circulating around the system.

As mentioned, I also wouldn't increase the pump speed.

Useful info, thanks.

BMWChap · 02-27-2018, 10:29 AM

Quote:

Originally Posted by JLR1969

Never hot.

This plumber is , this is scolding hot water lol I was in stitches for ages

https://www.youtube.com/watch?v=OP30okjpCko

JLR1969 · 02-27-2018, 11:39 AM

Quote:

Originally Posted by BMWChap

This plumber is , this is scolding hot water lol I was in stitches for ages

https://www.youtube.com/watch?v=OP30okjpCko

It just got worse didn't it.

Fair play to the plumber for sorting it, I thought he was going to do a runner

Broncho · 04-27-2018, 03:01 PM

Turns out it was the old system being mated to the new system after my house extension, I had a couple of radiators that had been switched off, I switched them back on when it was freezing and it clogged the system up with rust.

I've got a new pump and a magnetic filter and now it's fine.

Supposedly....

02-23-2018, 08:34 AM	#29
Alscoob Brigadier General 2119 Rep 3,066 Posts Drives: G31 540i M Sport Edition Join Date: Jun 2015 Location: UK iTrader: (0)	The man needs a proper plumber / heating engineer as everything here is speculation !
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02-23-2018, 11:34 AM	#31
F20MAW73 440i Gran Coupe, Auto 877 Rep 1,295 Posts Drives: 440i GC Join Date: Aug 2012 Location: UK, West Sussex iTrader: (0)	You could try replacing your manual radiator vents with Aladin auto air vents. Have fitted these before and they are are quite effective. http://aladdin-products.co.uk/products/autovents/ Also is the heating system water clean or dirty/perhaps full of magnitude sludge as this can cause poor circulation issuse and aerated water. If so the sysyem may need a decent chemical power flush and dose on completion with suitable corrosion inhibitor.
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04-27-2018, 03:01 PM	#36
Broncho Banned 2311 Rep 5,101 Posts Drives: Chav white Mercedes Join Date: Nov 2015 Location: Rainhill iTrader: (0)	Turns out it was the old system being mated to the new system after my house extension, I had a couple of radiators that had been switched off, I switched them back on when it was freezing and it clogged the system up with rust. I've got a new pump and a magnetic filter and now it's fine. Supposedly....
	Appreciate 0 Quote