open vent boiler remote from F+E junction - OK?

[skyblob]

Single storey kitchen extension where a new open vent boiler is planned for the outside wall.
(Old 1970's boiler in centre of house has no drain, and inappropriate concrete flue inside wall, so will be abandoned)

I want to stick with open vent system. Am planning to put pump and S plan valves in bathroom cupboard area. (Tool access rqd before anyone pipes up about electricity!). This allows more or less vertical F+E pipes on the boiler side of the pump.

So question is: The boiler will have ~5M horizontal run under the new kitchen floor, and then vertical of~2.5M prior to F+E junction and the pump and valves location. Is this liklely to be any problem? Personally I can't see an issue, but every installation document I look at seems to indicate the F+E junction always very close to the boiler (and pump) by default.

 

[kevplumb]

as long as it is close coupled and has a permenantly open path to the boiler

 

[skyblob]

Thanks for that. Almost there then.

"But you don't want it going downhill on the way"..

Is this so critical? The pipes come out of the bottom of many boilers, so they must go downhill by definitin - at least a little anyway. This boiler will be mounted at low level kitchen cupboard and pipes will go that bit lower into the screed. So that's certainly downhill. But if the pump and boiler stat both failed together, there would still be a permanent open vent, even if it had a slight downhill during it's path to the close-coupled junction.

 

[skyblob]

Thanks Mysteryman.

I have been looking at the Vallant Ecotec (pipes on top) and Worcester Bosch Greenstar Ri (pipes underneath - but with a little internal air vent tube in the boiler).