Combi or conventional? Your advice needed please

[sparkmanc]

Ive recently bought a house, that has a conventional system installed - with a cylinder and a tank in the bathroom, and the radiators piped in 8mm microbore off a manifold (fed from boiler in cu22mm)

Im looking for advice what to do for the best, I will be relocating and adding a few radiators, hopefully doing as much as possible myself.

What would you reccomend - Reusing the conventional system - This would mean moving the tank and cylinder into the loft, and also installing my new radiators in microbore off the existing manifold. I don't really like the 8mm pipes - but they seem to have done a job for 20+ years.

OR...

Installing a new combi system which would mean re-installing all the radiators in 22/15mm. But if i was to do this myself, it would only be in PVC pipes, which I gather off my other threads is pretty naff.

Either way I need to install a new boiler, not personally of course, the existing one is nackered.

Would appreciate any advice, ta.

 

[Gasman77]

No need to re-pipe just because you are installing a combi - if anything going to a sealed system is better in my opinion as it should stay cleaner than an open vent. Wether you can have a combi working effectively tho depends on how good your mains coming in is.

Regarding boiler choices mine would be a Worcester CDI or any Viessmann.

 

[sparkmanc]

So I could use the existing manifold system, with pipes to radiators in 8mm microbore, in a combi system?

 

[sparkmanc]

Also, how does the price of a conventional boiler compare to a combi?

 

[Gasman77]

yes no probs, have done this many times before. Combi is usually about 50% more than heat only boiler

 

[dextrous]

yes no probs, have done this many times before. Combi is usually about 50% more than heat only boiler

But you might get £20-£30 scrap for the old cylinder and offcuts of obsolete pipe. Hooray

 

[Paul Barker]

You would best flush the old pipes really well and fit a system water filter . The favourite on the forum is Magnaclean but there is a wide choice available today.

If staying with seperate hot water storage buy a new cylinder, all the used ones I take out have suffered greatly from time internally. False economy to put a new boiler on a 20 year old cylinder.

Budget boiler range system or regular boilers actually cost more than combis.

My recommendation system boiler new cylinder (y or s plan) powerflush and filter.

Barrier plastic is OK if you use good quality fittings.

 

[sparkmanc]

So you think im best just moving the cylinder and CW tank to the loft, and redoing the pipes as appropiate?

Also, whats involved in a powerflush, and whats it likely to cost - is it something I could do myself?

Many thanks.

 

[compheat]

you need to be thinking about the age of your existing boiler and how efficient it is, Ive already mentioned on another thread re INTERGAS combi boilers best boiler i've seen it will save you a fortune in the long run