Constant air in system

[bobotheclown]

Hi,

I have recently had a new Y-Plan installed to an existing boiler (Worcester greenstar 24ri), this was due to the 3 port valve sticking and the pump being quite old.
Now, when the hot water is on the boiler continually cuts out,however if the heating is on at the same time the hot water heats up fine but the radiators then fill with air and water is pushed out of the expansion pipe into the tank.
This then creates excessive banging throughout the house and the radiators then require bleeding.
The central heating works fine without the hot water being on.
Is it possible the pump is pumping in the wrong direction for the hot water only? (piped incorrectly) any thoughts would be much appreciated.

Simon

 

[Gasguru]

Post pics but pump should circulate water away from the feed and vent.

 

[Madrab]

Or towards the 3 port valve which ever you can see more clearly,

 

[Plumbkinobi]

Is it open vent system?

 

[Plumbkinobi]

You've replaced y plan for y plan?

 

[Plumbkinobi]

My mistake, misread post

 

[Plumbkinobi]

Sounds like a badly installed system, and previous to my post you've have replaced a y plan for a y plan

 

[Plumbkinobi]

Note I dislike y plan

 

[Plumbkinobi]

Note* most problems here are due to ill conceived and badly fitted systems

 

[Plumbkinobi]

And unlike most here, I'm will to admit that heating systems are not complicated. You've coverd all of the physics in GCSE science

 

[bobotheclown]

Find attached a picture of new set up and a picture of part of the old set up, it is a vented system and I have included as much information as possible.

some points to clarify.
1. heating works fine if only heating selected.
2. if only hot water is selected the boiler cuts out after a short time and it takes forever to heat up.
3.if hot water and heating are selected at the same time the radiators heat up fine and the hot water also heats up however the system then fills up with air and the radiators and pipes bang like crazy.

old set up

• bobotheclown
• 16 Feb 2015
• 1

new set up

• bobotheclown
• 16 Feb 2015
• 1

 

[Nige F]

Who put that in The 3 way valve is unable to vent air - it's all wrong

 

[bobotheclown]

Who put that in The 3 way valve is unable to vent air - it's all wrong

Here is another picture showing an auto vent on the hot water side of the valve.

Untitled

• bobotheclown
• 16 Feb 2015
• 1

Is this what you refer to ?

 

[bobotheclown]

Update to tests carried out.

The hot water and heating seem to be pumping the wrong way, the return is heating up first at the boiler.
Can anyone advise on this please?

 

[Gasguru]

Need a diagram showing the pipe layout....wheres the feed and vent connect?