Which Central Heating System Should I Choose?

[psy29]

Hi

I'm after some advice on which CH system to go for.

I currently have a conventional system with a 2006 Glow worm boiler in the cellar, hot water cyclinder in the kitchen and cold water tank in loft, running 7 radiators. The pipework is micro-bore and the radiators date back to the 1970s.

For the new system I need the following:
Change all the pipework
Change all radiators and install 8 new ones (keeping existing bathroom ladder)
Remove all water tanks from the loft to allow space for a loft conversion.
I will be adding a radiator in the loft in the future and the current electric shower will be replaced with a 'power' shower.

We are on a water meter, there are 5 in our family (3 children aged 10 -13) and generally only have showers.

I've had quotes from plumbers who are divided on which system to go with. Two have said ditch the existing boiler and replace with combi, whilst the other plumber has suggested keeping the boiler and adding a vented system. The vented system is quoted at £2700 whilst the combi from £2900 to £3500.

Any thoughts out there? Your opinions would be greatly appreciated. Thanks[/b]

 

[CombustionGuy]

Don't you mean a unvented system as you have removed the tanks from the loft it would have to be unvented

 

[psy29]

Don't you mean a unvented system as you have removed the tanks from the loft it would have to be unvented

You could well be right. All I know is I've been quoted for a 170 litre pressurised unit to accompany the existing boiler.

 

[Whitespirit66]

With 5 in the house, forget the combi. It will struggle to cope with more than one hot tap/outlet at a time. Your current set up is preferable to a combi for your situation as it can feed more than one hot outlet. Keep the boiler and go with an unvented cylinder as suggested.

The boiler, if serviced regularly, poss has many more years life left in it and can be replaced in the future when needed. Make sure your plumber checks your incomming main pressure and flow to make sure unvented is OK for your situation.

You won't need a power shower with unvented, just an inexpensive thermostatic shower mixer valve from approx £80 upwards.

 

[DP]

I would not bother changing the pipes. Chances are pipes will be replaced with plastic, which I hate. I would go to 15mm floor to radiator and leave rest as is.

Cylinder is preferable but with the young ones under shower 170l is not enough- I have a client whose two boys deplete 300l cylinder of hot water. If only one shower taken at a time, then combi fine. If combi breaks then nothing could work. If existing boiler breaks and UV been fitted, you can heat water electrically. Personally, combi puts bread on my table but customers I like would be advised to go for UV cylinder

 

[psy29]

Thanks DP and Whitespirit66

We are favouring the unvented system primarily because the plumber who suggested it has worked for us before. Otherwise, we are a little at the mercy of plumbers thoughts, so I appreciate your guys advice.

Whitespirit66 - obviously it will be cheaper to avoid replacing as much pipework as possible, but will it have any detrimental effect on the system if we only partially change the pipework?
For your information, the cellar runs under the entire house so access to pipes and ground floor is ideal - it is only the first floor where floorboards would have to come up.
Our preferred plumber is 'old school' and isn't into push fit fittings, but prefers copper. I know you're no crystal ball reader (!), but is he also likely to favour copper pipes rather than plastic?

 

[mogget]

If you want copper, you can specify copper, but be prepared for a price increase if the plumber was going to use plastic.

My CH pipework is all copper and I wouldn't have it any other way.

If the boiler's working well I wouldn't replace it yet just service, and repair as necessary provided its heat output is enough for your new system.

My preference is for stored hot water for a few reasons. Immersion backup for when the boiler breaks down is the most important for me (small household). I did have a combi when I moved in and disliked it.

I'm not a pro, just an experienced DIYer.