vented or un-vented. Any help gratefully received!!

[42bty22ad]

Hi all,
I have now received two quotes for work on my central heating/hot water system becasue the copper cylinder has been leaking and I would like to replace it before I refit the bathroom. My system:-

• Baxi maineco system 24 (fitted December 2015)
• Standard copper cylinder in the bathroom. Fed by large water storage tank in the loft.
• There is no small header tank. The old one is still in the attic and water supply to it has been cut off.

Our first plumber states that our current cylinder is unsuitable and will require replacing with an un-vented cylinder but also recommends replacing the whole system with a Combi.
The second has asked me what type of cylinder I would like and has given me the option of either a vented or un-vented.
Any information will be gratefully received!!

 

[joni os]

Can't understand suggestion to rip out a 14 month old boiler still under 3 year warranty and replace with combi.
Vented OK, if happy with existing shower, but if you prefer a more vigorous showering experience, change to unvented. When sizing cylinder be aware that increased flow at shower may require greater volume of hot water storage and ensure coil rating in cylinder,vented/unvented, is no less then the 24Kw of your boiler.

 

[42bty22ad]

Thanks for the reply Joni. I had thought a vented system needed an expansion tank in the loft.
So really I could just replace with another copper cylinder?

 

[kozak1968]

You need to check incoming mains pressure, static and dynamic and flow rate before you choose an unvented cylinder.

 

[42bty22ad]

Thanks Kozak.
Im still unsure what type of system I have. Can you still have a vented system with no expansion tank in the loft?

 

[42bty22ad]

Thanks Kozak.
Im still unsure what type of system I have. Can you still have a vented system with no expansion tank in the loft?

 

[ShaunCorbs]

Thanks Kozak.
Im still unsure what type of system I have. Can you still have a vented system with no expansion tank in the loft?

So you have to tanks in your loft? and you can have your heating pressurised but hot water still on gravity

 

[JCSPLUMBING]

Vented is just the hot water side. Central heating system would be sealed with an expansion vessel on that system. You would keep the large Cold water tank in the loft to fill the hot water cylinder and to allow expansion of the heated water with the open saftey vent above it also.

 

[42bty22ad]

Thanks all,
Had another guy around yesterday. As there is only one, large, water tank in the loft he stated that the 'expansion vessel' is incorporated into the boiler.
So I could just replace the leaking copper cylinder............or as we may extend into the loft, do I bite the bullet and change the whole system to a combi. Even though our current boiler is only 15months old.

 

[42bty22ad]

Thanks all,
Had another guy around yesterday. As there is only one, large, water tank in the loft he stated that the 'expansion vessel' is incorporated into the boiler.
So I could just replace the leaking copper cylinder............or as we may extend into the loft, do I bite the bullet and change the whole system to a combi. Even though our current boiler is only 15months old.

 

[Sparkgap]

Sounds like all that's needed is to replace the cylinder like-for-like if there's no issues with lack of hot water or pressure. Cheaper than going to all the hassle of putting in an unvented one.