Heating upgrade for loft Con

[Stants]

Hi All
Advise needed ( and gratefully received )
I have a bog standard ( excuse the pun )existing Central heating System ( I believe is a Gravity semi pumped system )
Lay out as followed
Boiler in Kitchen
Copper cylinder + grundfos pump and 3 way Valve in bathroom upstairs
CWSC + F+E tanks in loft
I'm converting my loft and I'd like to keep the same ( or as near as ) System as it's been so reliable
I having a small on suite with a shower
I'm proposing 3 options
What I'd like to down to what I may need to do

1 New uprated Boiler condensor ( prob Potterton or Worcester) in kitchen
Move / New Copper Cylinder, Pump up into loft along with 70 Gallon Coffin CWSC, F+E tank
Plus add Pump for Hot and Cold
and Rads
This is my preferred but think Space , Height ( minimum heights may come into play ) may be a big issue and not workable (Shame if it is :-(

2 New uprated Boiler condensor ( prob Potterton or Worcester) in kitchen

Leave Cylinder and Pump
Etc in first floor bathroom
( renew / upgrade all )

In loft New 70 Gallon Coffin CWSC, F+E tank
Plus add Pump for Hot and Cold and Rads

3 New uprated Boiler condensor ( prob Potterton or Worcester) in kitchen

Pressurised Mega flo
In loft and Rads


I'm aware you can get made to measure Cylinders and CWSC to maybe get option 1 to work
Plus up rating Gas and Water supply sorry if this is a big ask be Gentle

 

[ShaunCorbs]

If your flow and pressure are inline with specs I would go with option 3

 

[Chuck]

You almost certainly don't want the CH system to remain as vented with a modern boiler. Get it power-flushed and converted to unvented. Having no F+E tanks in the roof, if you can achieve it, will be nice.

So, definitely option 3 for me if the supply is suitable.

Personally, I really like Megaflos. I like that they don't need a separate expansion vessel and I think that they are well made from high quality materials. There are cheaper alternatives if you need to shave a couple of hundred notes off the price but I love my Megaflo.

 

[king of pipes]

Its hard to beat a unvented cylinder and modern condensing boiler you may consider a combi boiler to supply the kitchen sink or any downstairs hot outlets , coupled with a unvented cylider in the loft suppling upper floors , this saves pulling alot of tepid water off all the way from the loft to the kitchen sink ect , you must have a good incoming stable cold supply 3 bar and 20 litre + flow at your upstairs cold taps ? Regards kop

 

[Stants]

Its hard to beat a unvented cylinder and modern condensing boiler you may consider a combi boiler to supply the kitchen sink or any downstairs hot outlets , coupled with a unvented cylider in the loft suppling upper floors , this saves pulling alot of tepid water off all the way from the loft to the kitchen sink ect , you must have a good incoming stable cold supply 3 bar and 20 litre + flow at your upstairs cold taps ? Regards kop

Sorry im so used to my old System I'm not as familiar with the unvented ones are you saying a Combi Boiler with an unvented Cylinder ( megaflo or Similar ) in the loft are you suggesting 2 boilers
..... I'm on a learning curve with unvented
Ps it's not a large house

 

[Stants]

If your flow and pressure are inline with specs I would go with option 3

I've seen ( online ) a calculation for water flow .....Take the amount of water in the jug in litres (e.g. 0.8 litres) and multiply this by 10. This will give you your flow rate in litres per minute (e.g. 0.8 litres x 10 = 8 litres per minute). If your flow rateis less than 10 litres per minute, you have what is considered low water pressure. ...... does that work ? Also I've seen a gauge on screwfix for pressure it screws to the washing machine out let was thinking of getting that

 

[Stants]

You almost certainly don't want the CH system to remain as vented with a modern boiler. Get it power-flushed and converted to unvented. Having no F+E tanks in the roof, if you can achieve it, will be nice.

So, definitely option 3 for me if the supply is suitable.

Personally, I really like Megaflos. I like that they don't need a separate expansion vessel and I think that they are well made from high quality materials. There are cheaper alternatives if you need to shave a couple of hundred notes off the price but I love my Megaflo.

It looks like I'm having an unvented system as most suggest that but I'm just curious as to why modern boilers are not so good with vented ... what if you was just changing the boiler ? On an old system

 

[Stants]

It looks like I'm having an unvented system as most suggest that but I'm just curious as to why modern boilers are not so good with vented . what if you was just changing the boiler ? On an old system

Reason I ask I may have to replace my boiler sooner ( before Winter ) and I'm planning to do the loft early next year

 

[ShaunCorbs]

I've seen ( online ) a calculation for water flow ...Take the amount of water in the jug in litres (e.g. 0.8 litres) and multiply this by 10. This will give you your flow rate in litres per minute (e.g. 0.8 litres x 10 = 8 litres per minute). If your flow rateis less than 10 litres per minute, you have what is considered low water pressure. .. does that work ? Also I've seen a gauge on screwfix for pressure it screws to the washing machine out let was thinking of getting that

Easiest way see what you can fill in 10 seconds (x amount of l) and x that by 6

And yes or an outside tap

 

[Chuck]

It looks like I'm having an unvented system as most suggest that but I'm just curious as to why modern boilers are not so good with vented . what if you was just changing the boiler ? On an old system

Older boilers have substantial cast iron heat exchangers with relatively large channels for water to flow through. They were relatively inefficient as a result. This means that sludge arising from oxidation is not a huge problem as draining and flushing does the trick.

Modern boilers have much more efficient heat exchangers; much thinner walls, much narrower channels, much more prone to blocking due to sludge. Less metal to to survive corrosion. Flushing is much less effective due to the narrow channels.

Unvented systems have nowhere for the air that causes the oxidation and sludge to get into the system water.

It's not that a new boiler won't work on an unvented system, it's about how many years it's going give trouble-free service and whether any premature failures will be covered by the warranty.

Converting to unvented is usually a simple operation. The only 'risk' is that it will reveal any leaks in the system and these will need to be fixed. I'd say that this is a good thing, but householders sometimes incorrectly blame the conversion to unvented for causing the problem. Actually, they should be pleased because an undetected long-term leak can cause a lot of damage to a house.

 

[Stants]

If your flow and pressure are inline with specs I would go with option 3

Thankyou

 

[Stants]

Easiest way see what you can fill in 10 seconds (x amount of l) and x that by 6

And yes or an outside tap

Thankyou

 

[Stants]

Older boilers have substantial cast iron heat exchangers with relatively large channels for water to flow through. They were relatively inefficient as a result. This means that sludge arising from oxidation is not a huge problem as draining and flushing does the trick.

Modern boilers have much more efficient heat exchangers; much thinner walls, much narrower channels, much more prone to blocking due to sludge. Less metal to to survive corrosion. Flushing is much less effective due to the narrow channels.

Unvented systems have nowhere for the air that causes the oxidation and sludge to get into the system water.

It's not that a new boiler won't work on an unvented system, it's about how many years it's going give trouble-free service and whether any premature failures will be covered by the warranty.

Converting to unvented is usually a simple operation. The only 'risk' is that it will reveal any leaks in the system and these will need to be fixed. I'd say that this is a good thing, but householders sometimes incorrectly blame the conversion to unvented for causing the problem. Actually, they should be pleased because an undetected long-term leak can cause a lot of damage to a house.

Thanks for your detailed explanation it makes sense to change and by the time you deduct the cost of a new Cylinder, CWSC , F+E Tanks . Pump that could be offset towards A Mega flow Unvented the downside may be I don't have enough Pressure or Flow ( I'm going to check this ) just looking at costing this so other than Labour what would be needed to upgrade a conventional System to to an unvented ( ball park Figures ) small 3 Bed Semi with Loft Con 1 and 1/2 bathrooms plus a bit Extra Allowing for a Rear extension in the future ) I.e. Which Megaflo , Boiler etc

 

[Chalked]

Megaflo are overrated and overpriced. Go for a non bubble to cylinder, like santon premier plus, centerstore, RM, etc. These are cheaper, made of stainless steel and more reliable.

 

[ShaunCorbs]

Or gledhill

 

[king of pipes]

Sorry im so used to my old System I'm not as familiar with the unvented ones are you saying a Combi Boiler with an unvented Cylinder ( megaflo or Similar ) in the loft are you suggesting 2 boilers
... I'm on a learning curve with unvented
Ps it's not a large house

Yes a combi boiler which would supply all your heating and just the hot water for downstairs , paired with a unvented cylinder which would be in the loft and supply the other hotwater outlets if its a small house stick with just a combi you always have the option to add a cylinder if you should choose to later cheers kop

 

[Stants]

Megaflo are overrated and overpriced. Go for a non bubble to cylinder, like santon premier plus, centerstore, RM, etc. These are cheaper, made of stainless steel and more reliable.

Thanks I've been looking at the Santon brochure apart from Labour what components would you need to convert a vented to an unvented and I'm torn between the 210 / 250 ( 4 beds 1 bath 1 shower Small house ) tying to cost things