New Combi Boiler: now system doesn't fully drain

[Havab]

I've always been able to drain my central heating system effectively. However, I had a plumber recently fit a new combi boiler and add a couple of radiator. Now only one of the flow/return sides of the system fully drain. The other one keeps most of it's water.

I was thinking perhaps there is some directional valve on one of the new radiators or the boiler (GlowWorm flexicom cx).

The boiler and radiators work brilliantly, so I don't think it's been installed wrongly.

 

[CombustionGuy]

Why are you draining a new system ? Are the new rads on drops ( pipes from ceiling)

 

[Havab]

>> Why are you draining a new system ?
Moving an upstairs radiator

>> Are the new rads on drops ( pipes from ceiling)
No, just regular ground level ratiators with pipes coming up from the floor.

Thanks for your response.

 

[Agile]

But why are you draining a new system and wasting the inhibitor?

I presume he was one of the 50% of installers who did use inhibitor?

Tony

 

[Gasman77]

Is that exactly 50%?

 

[Agile]

No it varies slightly on the sample content.

Further complicated because they swear blind they do add it and say so on the Benchmark.

But then they sell the inhibitor on Ebay but with the sticky labels missing!

 

[Gasman77]

Do you have a cite for this statistic tony?

 

[xr4x4]

Where are the drain offs?