poor flow from open vented cylinder

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sparky

hello all
been to a new build install where cylinder is on the same floor as the bathroom and im not even getting 2litres/minuite from a flow cup with no flow restrictors in any taps. the downstairs kitchen and basin in the cloaks are giving around 5 litres a minuite but this is probably due to gravity pressure. Couldnt get access to loft to check if cold water cistern is ok? Could this be a blockage in the f+e pipe or in the hw circuit. If it was airlocked would i get any water at all from the hot taps?

Thanks in advance
 
if airlocked you can still get a trickle, but this seems more than a trickle. i had this recently with a new(ish) vented cylinder. it was crap in the pipes. got it through from the bath after a while.

Have you tried curing it as an airlock? it can help clean out the pipes too
 
Whats the F & E tank got too do with how much water u get from a tap?
May be better to get a basic understanding of how systems work before trying to fix them.
"on a new build" yer obviously in the trade and out of yer depth!
 
WHAT??? LOL. Feed and and expansion pipe from cold water cistern to hot water cylinder. if youre getting little water in to the cylinder surely youre going to get little out??
 
I think you mean the cold water storage tank, for hot water
The feed and expansion tank is for heating

if the taps are working well downstairs then the tank should have enoug water.
 
as someone else has suggested, i think you need to have a wee read at a plumbing book to refresh your memory on how an indirect hot water system works as it will make fixing it a lot easier if you understand what is/should be happening, ie what relevance is the cylinder position to the tap, unless it is a combined cylinder with a cold storage tank built in to it,
 
sure i was taught the pipe from the cylinder to the cold water storage tank was called the feed and expansion pipe as well? could be wrong lol. will dig out my books. get your point about the cylinder position though. Very sketchy on y plans very rarely see them on new build.Still, any suggestions?

Just looked through books and pipe is just labelled as cold feed ...however ...is expansion not taken up through this pipe??? I think so! So is this not a F+e pipe. Im not calling the cistern a f+e tank im calling it a cold water cistern.
 
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The pipe in question is the open vent pipe which is also a safety device should the cylinder overheat due to thermastatic failure. maybe it is blocked. could be pipe diametre or the gate valve on the cold feed is slightly closed.
 
it could be an number of things to be honest

Poor plumbing layout is one creating air pockets etc

Check the CWST in the loft though

Gravity systems are known to be low pressure but blockages do and can occur as well as air gaps!

Check for debris in the CWST though, might not even have a lid on it!
 
Cheers for the replies guys (and gals if there are any?) i new it wasnt going to be a quick fix but wanted to explore all avenues before attempting to fix.

Armo 74, expansion also taken up by the cold feed pipe back into the cold water cistern. Gate valve fully open. Only had a quick look as i only called to change some taps.
 
I might be wrong as i am fairly new to this so please feel free to correct me but the purpose of the cold feed from the cwsc is to refill the hot water cylinder as it is also pushing the hot water out the top via the vent pipe onto the hot water taps. But the cold feed from the f&e tank for the heating apart from keeping the system topped up it also allows for expansion back into the tank which is why the water level in the tank is less than that of the cwsc.
 
I not being sarcastic but quite a few of the respondents should go back to basics and have a read of ther level 2 books, you are all half way there but havent got a coprehensive understanding of plumbing. Some of you need to think a little before jumping in feet first with your responses, "no names no pack drill" old srvices saying really does apply here
 
Armo 74, youre correct in what your saying but as the water in the cylinder is heated the expansion will also be taken up by the "cold feed" pipe, back into the cold water cistern.

"no names no pack drill" never heard that before? not sure what it means?
 
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oldplumber said:
I not being sarcastic but quite a few of the respondents should go back to basics and have a read of ther level 2 books, you are all half way there but havent got a coprehensive understanding of plumbing. Some of you need to think a little before jumping in feet first with your responses, "no names no pack drill" old srvices saying really does apply here
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This is the place to get things wrong though isn't it and we can spot it put it right and feel good about our selves
 
dont see a problem with te refering to the cold feed as a feed and expansion pipe, after all the expansion rises equally in ALL pipes not just the vent. the vent is primarily to allow air in and out. Many people thinkit is only a expansion pipe for safety, if it was capped off the pressure in the system would NOT rise. i think calling the feed an F&E pipe shows quite a good basic knowledge of the system
 
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