Height of bottle vents.

[Chris12345678]

Hi, I need to install some bottle vents in the flow and return of the central heating pipes.
last time I fitted tee’s to the 22mm pipes, then a valve then the bottle vent. So the bottle vent was only 12cm above the pipe, this resulted in air being dragged in.
I’m going to refit them today as the system builds up air at this point, but extend the pipes from the tee’s to around a meter in length. So the bottle vents will be 1 meter higher than previous.

is this likely to be enough so that they vent air but air doesn’t get dragged in.
They will still be lower than the CH header tank and level with the top of he hot water cylinder.
Thanks.

 

[Donametchi]

Hi, I need to install some bottle vents in the flow and return of the central heating pipes.
last time I fitted tee’s to the 22mm pipes, then a valve then the bottle vent. So the bottle vent was only 12cm above the pipe, this resulted in air being dragged in.
I’m going to refit them today as the system builds up air at this point, but extend the pipes from the tee’s to around a meter in length. So the bottle vents will be 1 meter higher than previous.

is this likely to be enough so that they vent air but air doesn’t get dragged in.
They will still be lower than the CH header tank and level with the top of he hot water cylinder.
Thanks.

I take it from your post it is a system boiler.If you invert the feed to the boiler you should not require a spiral vent(Which I presume is a bottle vent).
if your having issues with this try filling the heating circuit via a garden hose through the drain off valve which should be located out side until the water comes out the roof over flow.Bleed all roads and hopefully how ever fitted the dhw storage tank fitted an air bleed valve failing that crack open the nuts on the return and flow at the cylinde.Also bleed the pump at the centre screw.Remember it,s a gravity fed system so basicall,Get the water through at all levels before you turn the boiler on to prevent boiler lock out.Good luck

 

[Chris12345678]

It says there’s a reply, but I can’t see anything?
I one of the many adverts covering it?

 

[SJB060685]

The installation of aav's should be installed on the flow where the temperature of water is hotter and solubility of air is reduced.
Perhaps more importantly though how is the system configured? Is it open vented or sealed?
Unless an aav is installed in a negative pressure portion of the system it should never draw air in.

 

[Last Plumber]

If your system has an issue with gas or air, then there is a bigger problem. If a system is installed correctly, it will not collect air or gases in the first place. You need to identify the issue you have and resolve it.

 

[Chris12345678]

All done now and seems to working well.
It’s for when the system is drained, upon refilling it is a right pain to get everything bled. The biggest problem is three downstairs radiators all on the same drop from the ceiling that get air locked.

Anyway, today I opened the valve to refil, turned off all the downstairs radiators except the three problem ones and they all came on, left it for a while and turned the rest on and all is working fine. No bleeding at all, although the two radiators without auto bleed valves will need bleeding at some point.

 

[SJB060685]

All done now and seems to working well.
It’s for when the system is drained, upon refilling it is a right pain to get everything bled. The biggest problem is three downstairs radiators all on the same drop from the ceiling that get air locked.

Anyway, today I opened the valve to refil, turned off all the downstairs radiators except the three problem ones and they all came on, left it for a while and turned the rest on and all is working fine. No bleeding at all, although the two radiators without auto bleed valves will need bleeding at some point.

With the pump running you might find any trapped air is circulated away from rads without bleed ports and able to bleed elsewhere. Do the two rads without bleed ports have half inch blanking ports on the top left and right? If so crack them open gently to try and bleed

 

[Chris12345678]

With the pump running you might find any trapped air is circulated away from rads without bleed ports and able to bleed elsewhere. Do the two rads without bleed ports have half inch blanking ports on the top left and right? If so crack them open gently to try and bleed

Sorry, all the radiators have bleed nipples, all of them except two have automatic bleed valves. The 1/2” connections on the sides are seized