Central Heating F&E tank pipe work

[Chineplate]

Looking for advice please. I have recently had my oil fired central heating boiler replaced and everything appears to be working fine. However, I have noticed that the vent pipe to the F&E tank has been installed on the return line at the point where the pipe work enters the boiler. The feed and expansion connection is as expected on the the flow pipe just before the pump. I have read several threads on this site recommending that these 2 pipes should be close together and on the flow side before the pump. Can anyone see any disadvantages of my setup or is it acceptable. The system was commissioned by an OFTEC registered engineer.

 

[DeltaT2]

Looking for advice please. I have recently had my oil fired central heating boiler replaced and everything appears to be working fine. However, I have noticed that the vent pipe to the F&E tank has been installed on the return line at the point where the pipe work enters the boiler. The feed and expansion connection is as expected on the the flow pipe just before the pump. I have read several threads on this site recommending that these 2 pipes should be close together and on the flow side before the pump. Can anyone see any disadvantages of my setup or is it acceptable. The system was commissioned by an OFTEC registered engineer.

To become OFTEC registered you only have to pay for & attend some courses, that are very basic - even on oil systems. So, any chancer can call themselves OFTEC registered.

It sounds like you have a bit of a wrong installation there mate, can you do a sketch & post it up, just to confirm what you've got. Photos if it's easier.

 

[Chineplate]

Here's a sketch that should make things a little clearer.

View media item 38526

 

[45yearsagasman]

That is wrongly configured. The vent pipe should be connected just before the cold feed (what you have labelled F&E) and within 150mm. The feed pipe and the vent pipe will be subjected to the same pressure no matter what.

 

[Chineplate]

I didn't think that the layout conformed to the generally accepted setup. I'm going to need some ammunition when I approach the installer so can you give me some idea of the implications of leaving the layout as is. Thanks

 

[45yearsagasman]

One probable scenario is that air could be drawn into your system.
I don't know oil boilers, so does it have a pump overrun, and do you have TrV's fitted to your rads? You don't show a bypass. If there is pump overrun when system shuts down its quite likely that air will get into your system piped like it is.
The work to cure this is minimal.

 

[Chineplate]

45yearsagasman.
Thanks for your response. No pump overrun, by-pass not required and TRV's throughout except where the Gnd & 1st floor room stats are located.

 

[Chineplate]

Gents

Sorry about this but I made a bit of a cock up on the original drawing. Both the F&E and vent pipes are connected to the return line and not as previously shown.

I fired up the system today to try and balance the rads. When first started there is quite a bit of gurgling and whooshing which I suspect is air in the system. This did ease off after a while, after quite a bit of Rad bleeding, but never cleared completely. I'm suspicious of the the vent pipe's position and wonder if it is functioning correctly. I know that this is not a conventional setup and your advice will no doubt be make it so. However, as I said before I need some facts as to why this is not a good setup to confront the installing plumber with.

Thanks

Untitled

• Chineplate
• 12 Oct 2011
• 1

Thanks

 

[45yearsagasman]

The feed and vent are not close enough together going by your new diagram. It should be as suggested earlier on the flow and just before the pump. That way the system pressure will be equal and will prevent air being sucked into system.
What do the MI's say about system configuration? I know of no boiler manufacturer that will describe a config with the connections on the return.
Having said that, it may well work perfectly, but it concerns me that you cannot get all the air out and stay out.