Unvented cylinder @ 12 ltr/min

[fizzput]

As unvented are designed for about 18 ltr/min +.....wondering, what happens if installed on a system with much less flow....is it just that there's then no benefit over a conventional vented system or is there a performance downside??

 

[muggles]

What exactly has less flow? Your mains? If that's flowing at 12l/min then you should get just under 12l/min from an unvented cylinder, although I'd be surprised if your mains is that low. There isn't a min flow requirement for unvented, but most use a 22mm supply, which you'll obviously only get if that's what's coming from your stopcock.

 

[fizzput]

Going back to property t-row so will check gate valve and mains stop valve....but supply to house is lead so looks like is being strangled by insufficient bore pipe....

Agree a suprise tho as my flat just 2 streets away has way in excess of 22 ltr/min, but has 22mm in flat with mdpe supply so....

Just wondered if technically there was a reason for unvented being maybe impossible on 12 ltr/min.....just a question i has no definite answer to myself..

 

[muggles]

No it's certainly not impossible, there's no min flow rate that I'm aware of, but it's a whole lot of expense to go to for little gain, if your flow rate is that poor and you're not intending to upgrade the supply then you may as well spend the money installing a decent combi boiler, which will provide you with 12L/min hot water and save a lot of space.

 

[fizzput]

For sure...thanks for clarifying that muggles,