Bungs and automatic vents

[jase158]

I worry about bunging tanks, the reason for this is.

1. they might pop out if there is reverse pressure or if not in properly
2. F & E tanks are dirty and last thing i want to do is get my self covered in muck before i have even started work.
3. cold water tanks are clean and don't want to contaminate it with my dirty hands

 

[TerryH]

Thanks for all the useful tips, gents.
On Saturday I have a trv to fit, so will try bunging the system (vented) first. I've copied out all your advice..... so heart beating rapidly and attempting to look confident, I'll give it a try.
I'm reluctant to drain down because the boiler is an old Potterton Flamingo, which will probably never work again once disturbed. ): and as you all say, it's an awful lot of work for one trv.
Say a little prayer for me!!!!
TerryH

 

[nijjy]

Hi TERRY - i have a big thank you to say to all the pros / experienced guys on here. I recently bunged my open vented system yo chang etwo rad valves . the same job that you are doing on saturday. Yes, I was nervouse also!! this is how I bunged. But I am in no position to advise!! but this is what I did and it worked, appropriately shaped potato 9a slim potato not a fat one in the expansion pipe. I then used masking tape a few wraps round to get a good seal. In the feed pipe I put the top of a silicon sealeant tube!! The lid you screw off before you use the sealant.. Now this lid was kind of "splined" on the outside, so i got a wood chisel and chiselled off the "splines" If you get a lid without the splines obviously you wont need to do this! after chiselling off the splines, I found that it fiteed into fee hole perfectly! The bung held while change the rad valves. I even left the bung in for a week to show my mate what I did. The bung did not hold absolutely water tight, but all it was was a very slow drip .I easily fitted my rad valves, even with this very slow drip. But best thing to use , to bung both expansion and feed pipe is probably a cork or rubber bungs - if you can find any round the house!! I couldn't. it you happy to spend money, its called a "drain easy kit" aat the plumbers merchants - someting like £15 at plumbase!! a lot of money for two rubber bungs!! all the best mate. Nigel - firs timer - and thanks again to the pofessional for taking their time to input into these forums.

 

[WaterTight]

you left a potato in your vent pipe for a week?

 

[nijjy]

yes I did!!

 

[fuzzy]

not many open vented systems have aav's mate as they should be designed out

 

[WaterTight]

yes I did!!

well i suppose if your system over heated you'd at least have gotten some lunch out of it

 

[nijjy]

did not turn on the central heating while bunged. However, the boiler was used to heat water for showering. Does the expansion pipe, [the one that drops over the F&E tank] act for the hot water also [in addition to the central heating]? I also have an expansion pipe dropping over my cold water feed tank, and this expansion pipe appears to come into the loft from a ceiling hole in the area of the bathroom.

 

[TerryH]

Thanks again.....
Nijjy, well, my mind boggles! Thanks for the advice. I'm using a 22mm speedfit end-stop on the vent pipe and have a choice of conical bung or expanding bung on the F&E tank, I'll see what the connector looks like. The sealant top could be good in an emergency, provided it isn't one of those with a pre-drilled end !
Fuzzy, thanks. I know what you mean but being a great pessimist I'm going to have a quick check. You're right, the vent to the F&E SHOULD be the highest point and therefore any AAV's should not be needed in an open vented system.

I have NO intention of leaving bungs in for a week
Thanks, gents,
TerryH

 

[dontknowitall]

By the time you lot have decided which size bung to use and whether to use a carrot, potato, piece of beetroot or whatever wouldn't it have been quicker to have drained the system?
:ninja: