Capped off vent pipe

[Bats177]

Hi

A few years ago I had a problem with a noisy central heating pump. Air was rushing through pretty much constantly, gushing and whooshing is the best way I can describe it. I called a local heating guy and he said that the pump is possibly pulling air down the header tank vent pipe. He the capped it off.

It always concerned me that he'd done that.

More to the point, it never did stop the problem.

I'd welcome any comments about the vent being capped off and any idea what the air problem is?

I do plan to put some Fernox F3 through to clean the system followed by some F2.

Many thanks in advance.

 

[St0rmer66]

It should concern you! It's there for a reason... if the cold feed blocks (which is always the first place to block) then your system water will have nowhere to expand but without the safety of a pressure relief valve that would be on a proper sealed system.

 

[kbdiy]

Firstly, open up the vent pipe again ... or sit back and wait for the bang!

Secondly get someone who knows what they are doing. If it didn't cure the problem then clearly further investigation is needed. Probably down to bad design in the first place.

 

[transam]

some boilers could be fitted with just a cold feed vaillant had one out many years ago

some ? loads ? of boilers are fitted with a combined cold feed & vent

An important question to be asked is , does your boiler have an overheat stat
fitted????????

 

[Bats177]

Thanks for your replies. The boiler is a 15 year old Glow Worm Ultimate which has a thermostat that I've set in the middle. The pump is a Wilo Gold 50. There's a bit of sediment at the bottom of the header tank but can't believe that this is causing all this air in the system?

So it might sound that I need to get it un-capped?

 

[Armo74]

Take the cap off the vent pipe.
You need to locate where the cold feed enters the flow from the boiler and try the magnet test.
Some pictures will help if you need assistance in locating it.
Are you constantly bleeding your radiators?

 

[Bats177]

Odd. I've just loosened the compression cap off and water started to come out so I re-tightened it. On closer inspection the engineer has re-routed some pipe work!

He has connected the cold feed in to the vent pipe. What I thought was the vent pipe that was capped off, is actually the original cold feed.

So to clarify... There's no vent pipe at all. The cold feed goes into the cold feed and down to the pump?

Does this change things?

Thanks again for your time all of you

 

[Bats177]

Sorry, that last bit should read.... The cold feed goes down the old vent pipe and into the pump.

 

[St0rmer66]

As long as it's in 22mm you should be okay. It makes it harder to vent a system but is usually better at keeping air out once you have vented it.

 

[Bats177]

Here are two pics. The disconnected cold feed you can see joining the 22mm? Old vent pipe just before in goes into the bottom of the pump. So that 15mm that you see is redundant.

 

[Bats177]

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• Bats177
• 16 Jul 2014
• 1

Untitled

• Bats177
• 16 Jul 2014
• 1

 

[jeff the gasman]

You have a magnetite build up that caused the pumping over. The pleb who sorted it hasn't got a brain and doesn't understand hydraulics.
Get a decent bloke in and he will sort it.
Listen to what he has to say and make your choice. If he doesn't seem sure try the next.
Jeff

 

[Armo74]

The reason the problem was still there is because the cold feed is blocked.
The problem pipework needs removing and re-piping.

 

[Bats177]

Thanks for your replies. Looks like I need to get someone in to possibly replace at least the cold feed and possibly a power flush.