Mystery, missing open vent on F & E tank.

[Dannypipe]

Hello all.

Got called to a late job (6pm) tonight. Someone saying their F&E tank was overflowing.

I get there, and yes the ball float valve was passing. (The float was under water too).

Thought to myself, nice simple job...then notice...there's no open vent. I then notice the bent peice of discarded 22mm pipe which would have been the open vent.

Spoke to client. British Gas did her boiler change in 2004. I looked at the invoice. They charged her for 'pipe alteration in 22mm'. Amongst other things.

Anyway, the client said she had to pay for BG to come back as she complained of air in the system. The engineer who came out said the first installers had cocked it up and it was sucking in loads of air. I can then only presume he went on the cut out the open vent.

I really had to look at it all very carefully to ensure I wasn't missing something, which would make me look like an idiot when BG came back out.

I then advised client, told her I would help as much as I can. She's now calling BG, I await their answer.

I've seen funny things done to open vents, Put to one side of the tank so it'll miss. Cut too long, Cut too short, but NEVER cut out all together.

Anyone else?

 

[tamz]

Diamondgas beat me to it but this is a standard method of connecting for low head situations with low water content boilers.



It may be old but it works well enough. It prevents pumping over and drawing air because of the volume of water. The expansion loop itself is irrelevant as it will still expand.

 

[paulnwales]

Paulnwales, please check out [DLMURL]http://www.idealheating.com/downloads/manuals/201787_inst.pdf[/DLMURL] page 11. NEW installations for Ideal Mexico. The use of combined f&e is still relevant today and can save a great deal of grief when an open system is the only option...

Without checking other manufacturers of appliances suitable for open systems I'd guess they'd all conccur on the alternative of combining the f&e pipes... You'll note that it is feed and expansion and not for venting. If you're faced with an issue regarding older open vented systems and concerned about pressurising them there are alternatives options still available that are relevant today...

Hope this has been of some help...

cheers i had a look at it, but in that case you also need a air seperator and auto air vent installing, i personally would not be keen on doing it..

 

[Dannypipe]

Wish I had this information before I advised the client. Its obviously fairly rare as I've not come across it before.

As I said, the original installers left the vent in place. The second BG guy (who the client says was an older guy) said they had plumbed it up wrong, and must have cut the open vent out. I'd like to convert it to a sealed system...however I've advised the client to contact BG. They may now be on the phone to me, telling me to go back to school!!

 

[paulnwales]

Wish I had this information before I advised the client. Its obviously fairly rare as I've not come across it before.

As I said, the original installers left the vent in place. The second BG guy (who the client says was an older guy) said they had plumbed it up wrong, and must have cut the open vent out. I'd like to convert it to a sealed system...however I've advised the client to contact BG. They may now be on the phone to me, telling me to go back to school!!

just tell them in your opinion (thats if you agree) and many others its not great to do, there is enough space above f&e to put one in so as far as im concerned it should be there.. there is a reason that its not really done anymore. over many years huge amounts of money has been spent on research into these things, if it was a great idea then the swan neck would never really be used. thats just my thoughts tho.

 

[diamondgas]

Wish I had this information before I advised the client. Its obviously fairly rare as I've not come across it before.

As I said, the original installers left the vent in place. The second BG guy (who the client says was an older guy) said they had plumbed it up wrong, and must have cut the open vent out. I'd like to convert it to a sealed system...however I've advised the client to contact BG. They may now be on the phone to me, telling me to go back to school!!

I happen to come from the old school where this was the norm Dannypipe. If you came in to this industry when sealed systems were the norm you'd know no different especially when you expect an open vent and feed seporate ... Always learning and still am 30+ years on .....

paulnwales -- I agree I'd rather seal the system myself.. Nice to know that there's an alternative when you get that iky feeling something might just not take the strain!!! lol

 

[paulnwales]

my thoughts would be if the first installer put it in and the second changed it.. was it changed correctly? i have seen some strange systems in the past 15 years or so that seem to work fine untill you change one little thing. cheers for the info tho... do any other manufactures allow it do you know?

 

[paulnwales]

let us know the outcome dannypipe please.

 

[Dannypipe]

Well many thanks for all the comments. Still lots to learn!

I'll see what comes of it and will report back with the conclusion. Checked the MI, and it seems a combined feed/vent is allowed. Oh well, I wasn't to know, I'm 32 so it's been sealed systems on everything I've installed, and always a swan neck open vent on the header of existing systems that I've worked on. No one knows it all!

 

[tamz]

The drawing in the ideal book is just an improvement on an inverted feed. Also "old technology" that works.
The purpose of the aerject is to act like a small header and slow the water down as it passes through. The feed(exp) within 6" is to keep it within the neutral pressure zone. The head can be kept even lower using this method.

 

[tamz]

Just about every boiler manu who do regular boilers will allow combined feed expansions. There are many ways to skin a rabbit and they only list the most common ways.
Here is another one from Vokera mynute he

 

[Dannypipe]

Update:

I called the client this morning with the additional info I gleaned from this thread. She said she had allready called British Gas and they were coming. I explained about combined feed/vents and that if BG charged her then I would pay her back.

They came out, two guys, a senior engineer and regular engineer. Found no fault but noted combined vent/feed and said that I was correct the second engineer must have cut it out to prevent the problem of air entering the system. They didn't charge my client. They then suggested that her plumber change the ball float valve!

I came over in the afternoon and changed the ball float valve free of charge.

So there you go. You live and learn. All credit to BG, they could have charged...and they had made the right call in the first place.

 

[Puddle]

Update:

I called the client this morning with the additional info I gleaned from this thread. She said she had allready called British Gas and they were coming. I explained about combined feed/vents and that if BG charged her then I would pay her back.

They came out, two guys, a senior engineer and regular engineer. Found no fault but noted combined vent/feed and said that I was correct the second engineer must have cut it out to prevent the problem of air entering the system. They didn't charge my client. They then suggested that her plumber change the ball float valve!

I came over in the afternoon and changed the ball float valve free of charge.

So there you go. You live and learn. All credit to BG, they could have charged...and they had made the right call in the first place.

respect to you Danny,handled really well

 

[Dannypipe]

Thanks mate!

 

[tamz]

Yes you handled it well Danny. Hopefully the cust appreciates the good intentions and effort you made.

There were many weird and wonderful ways of piping systems up that are being lost a bit as everything is being sealed.
Doesn't take much thought to throw in a loop of pipe on a sealed system, No matter which up down round about way it is piped it will work. Open systems needed a bit more thought to get right hence the amount of badly fitted sludged up systems which aren't helped when someone comes along a few years later and fits a new pump and sets it to speed 3.
You now know a way to pipe an open system if it has a low head or is drawing air or pumping over.

 

[Dannypipe]

Cheers, true. Lesson learned and that information is logged for future reference. I'm sure it'll crop up again sometime.