Cutting into a closed system

[soccercelt]

My brother is fixing up a house and after lifting up the concrete floors, all copper pipes where damaged! It's a closed system and were wanting to know, is it a case of just connecting new pipes to same, fill up with water then turn on or is it alot more tricky than a open gravity fed system. Both us have years of experience on gravity fed system but not any in a closed expansion vessel system.

 

[Scott_1979]

Yeah just cut into it and refill with with a filling loop and just take air out of the system in the usual way. I.e. Bleeding Rads. Remember to pop some inhibitor in the system

 

[joni os]

Provided you follow best practise procedures with your soldering the pipes won't care which system is in place. I prefer working on a closed system as it's easy to create a vacuum and avoid necessity for complete drain down.
Also easier to purge air from system.

 

[soccercelt]

Yeah just cut into it and refill with with a filling loop and just take air out of the system in the usual way. I.e. Bleeding Rads. Remember to pop some inhibitor in the system

Provided you follow best practise procedures with your soldering the pipes won't care which system is in place. I prefer working on a closed system as it's easy to create a vacuum and avoid necessity for complete drain down.
Also easier to purge air from system.

Has anyone any good diagrams I can follow. One thing I was getting confused with was seen 2 other 3/4 pipes near the boiler and can't see where they are going. Boiler in a tight location and hadn't lifted that floor yet. I was also curious incase closed system was dangerous if not plumbed correctly or I must be getting mixed up with a pressurised system.

 

[Riley]

They are both pressurised systems if you are this is unsure it might prove sensible to get a pro in

 

[soccercelt]

They are both pressurised systems if you are this is unsure it might prove sensible to get a pro in

I know a gravity fed open system inside out. Plumbed all my houses out in this method last 20 years and never had any problems. In fact, have worked on these systems with other plumbers. I do understand your concern about getting a pro in but all I need is some small info and could do this myself. It'd just a few issues needing ironed out. It's not as if I'm some rookie who doesn't know anything about plumbing/heating systems. Hopefully with help on here, I could get this completed over the wknd.

 

[Riley]

Fair enough you understand why we err on the side of caution as we have no idea of the capabilities of people using the form

 

[Best]

Sealed systems and open systems are just same pipework possibilities. (Except you don't have a feed and vent on open system. And some open systems have gravity pipes to cylinder, whereas sealed are normally always fully pumped)
Are you perhaps thinking of unvented hot cylinders? They are dangerous if installed wrong
You really need to get someone to check what you have and if nobody else is maintaining the system regularly then it should get some work. The expansion vessel needs its air charge done every year or so, close to whatever the cold fill charge is normally, for example. No point in just working on a system without knowing it is all safely done and complete

 

[soccercelt]

Sealed systems and open systems are just same pipework possibilities. (Except you don't have a feed and vent on open system. And some open systems have gravity pipes to cylinder, whereas sealed are normally always fully pumped)
Are you perhaps thinking of unvented hot cylinders? They are dangerous if installed wrong
You really need to get someone to check what you have and if nobody else is maintaining the system regularly then it should get some work. The expansion vessel needs its air charge done every year or so, close to whatever the cold fill charge is normally, for example. No point in just working on a system without knowing it is all safely done and complete

You see, this is what throws me off. I checked water tank in attic and there is what looks to me as an expansion pipe going into main water tank. Can't find an expansion tank, seen expansion vessel in hot-press so to me, I think it's closed system and if it is, I never knew it needed an expansion pipe. ill have to double check everything tomorrow.

 

[Riley]

Mate it sounds like you're getting the systems very muddled stick a few pictures up and we'll give some ideas

 

[Best]

You see, this is what throws me off. I checked water tank in attic and there is what looks to me as an expansion pipe going into main water tank. Can't find an expansion tank, seen expansion vessel in hot-press so to me, I think it's closed system and if it is, I never knew it needed an expansion pipe. ill have to double check everything tomorrow.

Expansion pipe going into large cold storage tank? Is that not just the vent pipe from the top of the hot cylinder, if an open vent hot cylinder?
You sometimes get a heating expansion tank fitted in hotpress by plumbers. It is normally red in colour if a heating expansion vessel, although you can't always depend on colour. Would be a very easy job to visually check what system it joins to, - heating (or unvented cylinder).
The unvented cylinders that have external expansion vessels usually have white, or less commonly blue vessels.

 

[soccercelt]

Expansion pipe going into large cold storage tank? Is that not just the vent pipe from the top of the hot cylinder, if an open vent hot cylinder?
You sometimes get a heating expansion tank fitted in hotpress by plumbers. It is normally red in colour if a heating expansion vessel, although you can't always depend on colour. Would be a very easy job to visually check what system it joins to, - heating (or unvented cylinder).
The unvented cylinders that have external expansion vessels usually have white, or less commonly blue vessels.

Yes that's what I was thinking it was. You see, I can't follow the pipe to see exactly where it's going but there's a bent copper 3/4 pipe bent round and into the storage tank. I was of the thought if it was a closed system then it didn't need a vent pipe. There's defo a red round expansion vessel in the hot press. With no expansion tank, a red vessel I naturally thought it's a closed system however when I seen the 3/4 pipe bent into the storage tank and 3/4 pipe coming out of top of cylinder, this is what's confusing me because I always thought closed system didn't need the 3/4 pipe out top of cylinder.

 

[Riley]

Pics buddy

 

[soccercelt]

Pics buddy

I will tomorrow. Have to pop into his house tomorrow so will sort pics then.


Been looking at some diagrams online and what I'm guessing is, basically an open and closed system is the same only the pipe in open system going to expansion tank, it goes to an expansion vessel on a closed system. I might be wrong though

 

[Riley]

But you say it has both