Reasons for water coming out of feed and expansion pipe.

[tapsworcester]

I got to work today (on a caravan park) to find that water was coming through the ceiling in the boss' house. On investigation in the loft space I found a galvanised steel pipe on a 45 degree angle with water coming out of the end. The site manager instructed me to cap it off and I decided to use a compression stop tap as it was the only thing we had in 22mm copper (only the end bit was galvanised steel). However, when cutting into the pipe it started spouting hot water but the site manager said to cap it anyway. Well, during the day I started to think back to my plumbing course and decided that this pipe might be a feed and expansion pipe, which of course should never be capped off (I have opened it back up to an overflow outside the building).

My question is, what could have happened within the system to make water start coming out of the feed and expansion pipe? Could it be an increase in mains pressure? Could the coil have gone in the hot tank/ hot water storage vessel? Or, is it something else? I am waiting to see tomorrow morning whether it has started overflowing again, which might indicate an event during the daily cycle that has triggered this off.

All help gratefully welcomed. Thanks, Martin

 

[ShaunCorbs]

depends on what type of system it is any pics eg boiler etc and was the pipe into a glav/plastic tank 1"x1"x1" (foot) aprox

 

[macackau]

If your boss asked you to cap off the expansion he could have caused an extremely dangerous situation, you or someone else could have got hurt. I would strongly advise getting someone in who knows what they're doing. I understand you're trying to solve the problem yourself but I wouldn't want to be in your shoes when a hot water tank or central heating system bursts as the excessive pressure build up in the system has no where to go!

 

[IDCHAPPY]

Never cap off an expansion pipe, unless your ripping out a cylinder or sumfink.

 

[tapsworcester]

1. I am SURE that I stated that a F+E pipe should never be capped off, so thanks for the advice there.

2. Can anyone answer my question, which was along the lines of what could have caused water to start overflowing from the F+E pipe when previously this setup worked fine? The pipe does not terminate over a cistern. From what I have seen of the system in a very old house, a system boiler has been added but the HWSV has not been removed. A Gas Safe/ Oiltec/ HETAS plumber is visiting on Thursday and I will be asking him more about it as he put the boiler in, but some suggestions as to what has gone wrong before then would have been useful.

 

[macackau]

You did state that a F and E should never be capped off but you still capped it off?!

I had one a few weeks ago and the reason it was coming out of the expansion pipe was that there was a blockage in the pipe work. The expansion pipe was clear of blockages and water being lazy takes the route of least resistance which was up the expansion pipe.

It's an open vented system so its susceptible to corrosion and sludge build up which could have caused a blockage.

 

[ShaunCorbs]

as above sludge or water getting to hot (boiling over) etc could be alot of things but without seeing it its a guess at best

 

[SavageW]

As others have said normally blockage, maybe round the "H"