Sucking AIR

[PCDOCTOR]

Sorry Dan you have lost me now

You obviously don't mean the Automatic bypass valve

Feed me a little more info and i might just catch up with you

 

[Dan Robinson]

You were talking about diverter valves, now you are talking by-pass valves. Where you put the latter is dependant on where you put the former.

However, to save argument, and confusion I would put the by-pass where valve 3 is located, which would be easier if you have a DU144, otherwise, is it just three elbows.

Assuming that is you are putting the diverter valve where I think you are?

 

[chrishutt]

You can fit the ABV more or less anywhere after the pump provided that there will always be a route open (including the ABV) for circulation from flow to return to take place whatever the status of motorised valves and TRVs. Downstream of pump and before any motorised valves satisfies that but is not the only option.

 

[doitall]

You were talking about diverter valves, now you are talking by-pass valves. Where you put the latter is dependant on where you put the former.

He was talking about valve 3 on his drawing Dan

If pcdoctor adds an email address to his profile or sends it to me I will knock up a drawing tomorrow night for him/her, showing where/how the 3port goes.

 

[Dan Robinson]

I know, but something about that diagram makes me think there is a chance of reverse ciculation if the by-pass goes where the latest diagram indicates.... Where valve 3 is located feels better to me... We are talking valve number three not a 3-way valve .

Perhaps its getting late... .

 

[doitall]

I was looking at that happening as well Dan, it would be possible in the new possition.

 

[PCDOCTOR]

It is getting late

Yes i was going to slip in the auto by pass after the pump as the diagram shows then next week slip in a 3 port valve so i can eventually get some control with what i want

I Hope doing as the diagram and closing valve 3 should take me to the next level of this project and relieve some pressure of the pump when all those TRV are shut

Look forward to your support and banter also

 

[chrishutt]

something about that diagram makes me think there is a chance of reverse ciculation if the by-pass goes where the latest diagram indicates....

How can you have reverse circulation through an ABV? It would act as a check valve against reverse circulation.

 

[PCDOCTOR]

Here next weeks project showing 3 port mid position valve



Any problems with this speak now or forever hold your piece

 

[chrishutt]

That's fine, but as a matter of interest you could even branch it off the CH flow pipe after the 3 port valve since the ABV will only operate when the 3 port is closed to HW and most of the radiator TRVs are shut.

 

[doitall]

Looks ok although you could still get some creep into the radiators in the hot water only mode, still prefer the existing position

 

[PCDOCTOR]

so

You would prefer (Better performance) to rip out Isolate Valve 3 Stick in the ABV in it place

I'm easy and you guys have done it more often than me

All i have to do is get 3 elbows and reducer to bring it down to 15mm

The only reason i chose that position was looking at boiler manufacture websites and they show it like i have drawn it straight after the pump and before the 3 way valve

 

[doitall]

Now that is perfect, note no tees after the cylinder joins the common return.

Although the ABV is show upside down

 

[chrishutt]

.. you could still get some creep into the radiators in the hot water only mode,

How? I can't see any problem with PCD's proposed position. As he says the pipework's simpler and the existing by-pass route (valve 3) is in a long run of 15mm which many boiler manufacturers would consider inadequate.

 

[Dan Robinson]

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DIA sia.