Help to identify this part

[friendlyaviator]

Hi All,

In a quest to identify the source of a noisy heating system I am considering the function of this part:-



Is it some sort of check valve? If so how do I know it is working as it rattles when I tap it and also what is the seized screw in the middle for?

Does anyone know the symptoms if this part no longer does it's job.

Thanks in advance,

Dean

 

[Rickster123]

I'd say its a not return valve mate. I've found you a youtube moment to explain all..

HOW NON RETURN VALVES WORK - Plumbing Tips - YouTube

chop it out and change it if its rattling.

 

[friendlyaviator]

I'd say its a not return valve mate. I've found you a youtube moment to explain all..

HOW NON RETURN VALVES WORK - Plumbing Tips - YouTube

chop it out and change it if its rattling.

Thanks for an amazingly quick reply - on a Sunday! Could this be faulty and keeping air in my central heating system?

Also - how do I chop it out whilst preserving enough pipe to fit a replacemet?

Dean

 

[Rickster123]

The new one should be a direct fit. Just undo the nuts and olives. Have you had a new boiler fitted recently?

 

[Dotty]

Or have you had an oil link up?

 

[friendlyaviator]

The new one should be a direct fit. Just undo the nuts and olives. Have you had a new boiler fitted recently?

Thanks again,

I've not had a new boiler fitted. I am having a terrible time with gurgling when firing up a cold system, and then a periodic air noise tricking through this valve. No amount of radiator bleeding or pump speed variations will stop it.

Is that a bleed screw in the middle I see?

Dean

 

[stevetheplumber]

chances are you dont even need thid valve depends on what boiler you have now and pipework layout usual cause of your symptoms are blocked cold feed or pump on its way out

 

[Chalked]

That's an anti gravity vsalve. Very lightly sprung non return valve, they were fitted on the heating flow when you have gravity hot water. They stop the rads working when the hot water is on.
if you no longer have gravity hot water it can be removed.

 

[happyflyer]

Sure looks like a NRV but would still like to see all the plumbing below the photo just to make sure, the screw may well be a simple air vent to let out water if the valve is closed ...........https://www.google.co.uk/search?q=i...QaK7oGgBg&ved=0CFEQsAQ&biw=1361&bih=866&dpr=1

 

[friendlyaviator]

Hi all and thanks for the great replies...

Pump is new...
I have gravity hot water still...but pumped vented heating

The left pipe is the return to the boiler and the right pipe if the flow from the boiler. There is a pump at the bottom of the return pipe.

I have no heat circulation issues, just trickling water when pump starts from cold and the occasional trickling sound when heating is running.

Dean

 

[Anton]

It's definitely an anti-gravity valve, and it's probably blocked up with sludge and debris, hence the trickling noise. The screw is a manual air bleed. Best to replace it, which will require draining the system unless a freezer kit is employed. (If it's above the boiler then drain the system)

 

[friendlyaviator]

It's definitely an anti-gravity valve, and it's probably blocked up with sludge and debris, hence the trickling noise. The screw is a manual air bleed. Best to replace it, which will require draining the system unless a freezer kit is employed. (If it's above the boiler then drain the system)

Cheers. I've bought a replacement. I'm comfortable with draining and replacing this valve. Fingers crossed it will fix my issue.

One other question, as my TRVs shut down I can hear the pump noise in the pipe work. Is there a way to slow the pump further. It's on setting one of three at the mo.

 

[Chalked]

Cheers. I've bought a replacement. I'm comfortable with draining and replacing this valve. Fingers crossed it will fix my issue.

One other question, as my TRVs shut down I can hear the pump noise in the pipe work. Is there a way to slow the pump further. It's on setting one of three at the mo.

while you are drained down fit a automatic bypass vvalve between the flow and return.

 

[friendlyaviator]

while you are drained down fit a automatic bypass vvalve between the flow and return.

What does this do then? The only place the flow and return are near each other is just above the boiler in the photo shown.

 

[Chalked]

What does this do then? The only place the flow and return are near each other is just above the boiler in the photo shown.

That's a good enough position. It's a spring loaded valve that opens progressively as your thermostatic valves close

DU145 Automatic Bypass Valve - Honeywell UK Heating Controls