Which Replacement Central Heating System (CHS)?

[BriscsWK]

Hi,

We are 2 occupants with one main bath/shower and one en-suite bath;
25 year old Ideal conventional boiler with vented tank, and I am guessing original pipe work (solid ground floor) and radiators of 40 years; and
the tanks recovery time is ‘pants’ – I guess that is due to it being a gravity arrangement.

As the boiler cannot go on forever and as we are considering a new bathroom and would like good water pressure for showering we are considering what to do with the heating system in general.

Would anyone have opinions on (or in general):

Whether we should bite the bullet and have a total new system including replacement radiators etc with all new pipes or whether we could still utilise the existing pipes?

Which type of CHS – Combi based or an unvented system to obtain good hot water pressure? I suppose we could still have vented system but that would mean power shower pumps etc I think?

If we go combi route is it then best to go for a storage type combi (I am not keen on the idea of slugs of cold water flowing after you turn the hot water on and off, which I believe is a problem with basic combi boilers?) with a high hot water flow rate and if so which make and type to go for?

From my forays on websites the following would appear contenders:

Alpha CD50;
Vaillant ecoTEC Plus 937 HE Power Store;
WorcesterBosch Greenstar Highflow 440; or
Glow-worm Ultrapower 100sxi.

I know it is a long first post but any thoughts you may have would be appreciated as it would be good to be forewarned before heading into the acquiring of quotes for the work.

Many thanks

 

[Andy165]

Existing pipework should be ok but new rads recommended. Vaillant system boiler and unvented cylinder for good ch and excellent hw delivery providing you have adequate water mains pressure

 

[BriscsWK]

Tks, but I am still not convinced we need and unvented system for just the 2 of us and do like the idea of having hot water on demand

As you can guess still cogitating!

 

[Agile]

It would be a good idea to have a new efficient boiler.

However, proper hot water performance and perhaps 10% saving in gas cost would be obtained if you had proper controls and a pumped feed to the cylinder.

We used to do that conversion for £240 but usually fitted a second pump on the HW rather than modifying the pipework and fitting a three port valve as thats was often very difficult because of pipe runs etc.

That would give you reheat within an hour as well as a properly controlled temperature. The boiler would then only come on when heating the HW was required rather than cycling inefficiently.

Tony

 

[gas4you]

First thing you need to ascertain is your water pressure and flow rate from the cold mains.

You will need around 20 l/min and hopefully about 3 bar to get the full benefit from any of the boilers you have mentioned.

Personally I would choose the 937, or if you want real quality then one of the ATAG Q series.