help needed with dead leg/air pocket plz

[SniperOne]

Yesterday I was called to a house that had running water from underneath the bathroom floor, after removing parts of his newly fitted floor and furniture to gain access I discovered that a capped off piece of 22mm H/W pipe was leaking. This cap was on the end of a 2/3" stub out of a T-Piece that I assume was once used to feed H/W to the Bath before it was moved.

I cut this pipe T -Piece section out and drained out as much of the water as I could before rejoining with a new length of 22m copper and a couple of straight couplers. Problem/Leak solved.

Today, I receive a call saying that when the C/W taps are turned on, the boiler (Vaillant 824) displays the pump symbol and trys to engage the pump?

I have been told that this is a common problem when work has been carried out and an "Air Pocket" is formed via a "Dead Leg"?

The only other place I know of on the pipework where there may be a "Dead Leg"is a capped off C/W pipe that was next to the Hot that I had removed due to the leak. This capped off pipe is again on a stub about 2/3" long off an Equal T-Piece.

Has the removal of the H/W capped off section of pipework thrown an in-balance into the system?

How did the air get in?

How do I overcome this problem?

Do I have to lift up the floor etc again to remove the C/W capped off pipe?

Thanks in advance.

 

[onlyfitidealboilers]

fitt a mini epansion vessel to the cold water main problem solved

 

[SniperOne]

no other replys???

 

[londonboy]

Whats wrong with the reply above?

 

[kevplumb]

Whats wrong with the reply above?

don't you know

 

[londonboy]

Whats wrong with the reply above?

don't you know

Na aint got a clue, just thought it was cheeky
(I'll wander back to join the sparks )

 

[kevplumb]

it will work but its treating the symptom not the disease

give my love to big gob when you get back to the sparks

 

[londonboy]

give my love to big gob when you get back to the sparks

Well whos that then?

 

[holty]

or just leave the system for a couple of weeks and the problem could go away. if not try a single check valve on the hot outlet.

 

[SniperOne]

Thanks for all your replies.

Spoke with Vaillant Tech and they said that I have to remove the "Dead Leg" as the air in the sytem is throwing the flow switch into thinking that H/W is required?

 

[SniperOne]

or just leave the system for a couple of weeks and the problem could go away. if not try a single check valve on the hot outlet.

customer rung and said all seemed okay now