improving pipework for feed and vent

[chris5346]

filter is low because the pump used to be very low , i raised the pump and valve recently because i couldn't tighten the pump fittings, i left filter where it was,
the filter is a fernox compact one and it says can fit on flow but better on return., i plan to fit boiler in a kitchen cupboard so i'm not sure about filter yet, filter is handy there because it catches air before it goes into the rad pipes.
i guess if the Tee's and surrounding pipes are a bit blocked i will replace and keep separate feed and vent, but if they are clear guess i'll combine them.
the worcester manual shows a picture of seperate feed and vent.

 

[chris5346]

so are these my best options ?
what about those elbows on the returns ? is it worth sweeping those a bit better ?

 

[Razor900]

On my phone so may be making a tw@t of myself cos the pictures are small.

It looks as if the flow and return come off the bottom of the Ri with the vent on the top of the flow and the feed on the return?

In that case the vent will be under negative pressure when the pump is running which is bad!

 

[chris5346]

i don't understand what you mean, here's a few more pics:
some of the drawings i have added are not proper photos but proposals drawn using windows paint.

 

[Razor900]

Is the vent the tee on the flow and the feed on the return?

If so try and follow it through logically.

It goes feed, boiler, vent, pump. The vent will be subjected to negative pressure because of the pump and will suck air in.

 

[chris5346]

no all connections are on the flow pipes, it goes : boiler, 22mm vent, 15mm feed, then pump is about a meter away.
this is what i'm thinking to cut out :

 

[chris5346]

i will remove some more of the kitchen ceiling and just make sure which pipes run to the pump.
appreciate your help, i will post back tomorrow with some pics of inside the pipes

 

[D_Hailsham]

Is the vent the tee on the flow and the feed on the return?

If so try and follow it through logically.

It goes feed, boiler, vent, pump. The vent will be subjected to negative pressure because of the pump and will suck air in.

It's a modern condensing boiler with a high resistance hex. Your suggested arrangement is no good in that situation. The vent and feed need to be on the same side (normally the flow), before the pump and within 150mm of each other.

 

[Razor900]

Is the vent the tee on the flow and the feed on the return?

If so try and follow it through logically.

It goes feed, boiler, vent, pump. The vent will be subjected to negative pressure because of the pump and will suck air in.

It's a modern condensing boiler with a high resistance hex. Your suggested arrangement is no good in that situation. The vent and feed need to be on the same side (normally the flow), before the pump and within 150mm of each other.

Whose suggesting it??

Try reading what I put

Thanks for the clarification OP. Everything still points to a restriction in the cold feed. Time to combine them

 

[chris5346]

so where abouts on the cold feed do they get blocked ? at where i have marked the green circle or the blue or does just everything get blocked ?

 

[chris5346]

if i'm combining feed and vent i may just re-pipe everyting from the boiler rising to the pump, depends if i can borrow a decent pipe bender,
there's a poor bend where it comes through the floor into the pump - the bend has ripples/crease marks on it and there's another compression fitting between that and the pump i could remove , difficult to decide what to do until start working on it.

 

[chris5346]

i want to combine the feed and vent if possible , it will end up simpler and easier for me to do, as long as the system fills ok , the boiler does have an over temp. cut off. one thing that was quite handy is when i had any airlocks when filling i used to blow down the vent pipe and free it all up.
anyway i'm jumping the gun abit first thing is to see if it's blocked or not

 

[DP]

Chris, you can do whatever you want, but does that mean what you, sorry your plumber , is doing is correct?

Why are you so determined to cut out a perfectly piped Feed and vent to convert to single pipe? If present format was so wrong, why would almost every manufacturer suggest that method of header tank plumbing?

Seems you have convinced yourself where the problem is regardless of what remedy has been suggested by the regulars

This task, it seems evident, is taking the DIY route as almost all pros would plumb the system like what the current route is. This format will NOT, pump over even with max pump speed, if it is clean

Reading you several replies, issues may well be what is being implemented without locating and correcting the actual defect.

Why would the filter where it is, collect air and not the motorised valve? Which is higher, motorised valve (where the air would naturally collect) or the filter? What makes you think the air will not come off the top of the boiler, and then self purge up the vent? The vent on the filter (know what you have and what model also ) is to purge air from the can. It would have been advantageous to have the filter raised, to allow the sludge cock to run into a vessel placed below the filter.

 

[DP]

Is the vent the tee on the flow and the feed on the return?

If so try and follow it through logically.

It goes feed, boiler, vent, pump. The vent will be subjected to negative pressure because of the pump and will suck air in.

It's a modern condensing boiler with a high resistance hex. Your suggested arrangement is no good in that situation. The vent and feed need to be on the same side (normally the flow), before the pump and within 150mm of each other.

Whose suggesting it??

Try reading what I put

Thanks for the clarification OP. Everything still points to a restriction in the cold feed. Time to combine them

Razor, reading your reply, seems to suggest the vent is on flow and feed on the return
Pipe run is boiler (have looked at various WBs, piped behind the boiler it seems instead of off the top so unable to say for sure if flow and return are not reversed), vent and feed close coupled, pump, mv, right to rads with filter inline and left port to cylinder (vented) and gated

 

[chris5346]

so how can i clean it without cutting it ?
i don't really have a pumping over problem now , it's more air in the system i want to sort out and if combining feed and vent helps with that even if it makes system slightly less safe then i'd rather do it.
the air vent on water side does collect some air but i thought the pump was running too fast and air passing past it.
i don't know, i'll cut the connections out and see how blocked they are.