central heating dilemma

[john1]

hello everyone new to forum and have query regarding my central heating setup.
basically one vaillant turbomax 242 in kitchen.
22mm c.h pipes up to bathroom above and a few feet along.
10mm copper pipes directly joined to this for all rads in house.
10mm pipe to towel rad then progresses 12 feet along landing and down to ground floor 600x1400 one panel single convector rad.then another 12 feet and branches to right to bedroom similar rad.next a few feet and down to ground floor similar rad. a few more feet and at top floor rad.
so only 4 rads and towel rad all fed off same 10mm pipe.
is this ok? towel rad gets hot and first rad on circuit but others poor especially last rad which takes forever and only gets luke warm.system has been powerflushed(not helped much!) and b.g says needs repiping.
willing to get new rads and repiping but only if this would help flow and everything gets toasty hot.
have taken trvs off rads and boiler control on top whack but no difference.
sorry for all the info but hope somebody can give me their professional thoughts on this.

 

[newbie1]

no reason microbore shouldnt get hot..who did the powerflush and using what equip
my son flushed a microbore system and it got toasty hot faster straight away cant see repiping would be needed unless the orig piping has been incorrectly run

 

[Plucky]

System is underpiped, repiping in 22mm with 15mm drops would help greatly.

 

[john1]

powerflushed by birmingham company dont know about equipment but was attached to boiler pump throughout process. rads seemed to get hot with additional pressure whilst being flushed and got some crap out. just thought it maybe something to do with all rads being teed off same 10mm pipe wouldnt 15mm run of main 22mm pipe b better?had quote from c.h engineer who talked of manifolds and seperate pipes to each rad whilst informing me my gas supply pipe which is 22mm reducing to 15mm a couple of metres before the boiler may be the problem. quoted £2200 including new rads? still baffled any other ideas. cheers

 

[Flanners]

The engineer is exactly right.
10mm Flow and return to each intervidual radiator from a 22mm circuit (manifold)

price sounds ok aswell.

 

[john1]

thanks for that so 2 options 22mm to 15mm for rads or 22mm to manifold with 10mm pipes. mmm. but which is better than the other or are both reliable and likely to get reqd flow etc.
thinking of time and materials, on "balance" (get it?) suppose both would cost roughly same.
anyone used any of above regularly when plumbing with consistent results?

 

[timlaz]

hi there,

yeh pipe work is way under sized. you'll need run at least 15mm, and preferable 22mm to first couple of rads (flow and return, not to actually rads) then 15mm thereafter.

tim

 

[Plouasne]

hi there,

yeh pipe work is way under sized. you'll need run at least 15mm, and preferable 22mm to first couple of rads (flow and return, not to actually rads) then 15mm thereafter.

tim

Surly this depends on the radiator size, and the circulator head available ??

This is what get me, on this forum, the amount of bland statements "you need this" with out any qualification to the statement

 

[stevetheplumber]

Surly this depends on the radiator size, and the circulator head available ??

This is what get me, on this forum, the amount of bland statements "you need this" with out any qualification to the statement

its not rocket science plousane were looking at a domestic premesise with a 24kw combi available pump head is fixed by the manufacturers rads are not going to be huge so we can use our experience to make sweeping statements theres always loads of ways to skin a cat but the end results will be the same
personally id rerun the rads in ten mm back to the 22mm f and r you can actually run 2 small rads of one pair of 10mm pipes as ive done it when an extra small rad was wanted in a previously unheated toilet babc to back with a towel rail

 

[david williams]

skin your cat as you like(do you have a foul traders licence if you intend to ) but you can not push the energy needed for the rads fitted through such a small pipe