Combi or Boiler and Cylinder. Help choosing please

Postby Paul Benington » Wed Jun 27, 2007 2:38 pm

My hot water cylinder is leaking, the only way to get at it, to replace, is to pull the boiler out. Approx £700

Alternative is to replace with a more efficient combi boiler at approx £2500

Any recommendations/suggestions please????

I live in a 4 bed end terrace house on 3 floors, it costs me loads in Gas. I have two elec showers and one bath. In Sheffield

The existing boiler is a 5 year old Saunier Duval 8O ff, 20.52kw with a seasonal efficiency rating of 76-79% Band D or E. It works fine but my gas bills are massive

The new combi's i am considering are either Worcester Bosch or Valiant, both A rated for efficiency with similar seasonal ratings. Worcester is 30kw. Valiant is 28kw. A rated. The £2500 includes running bigger 22mm copper piping to the new boiler.

The Energy Trust have advised i would only save aprrox £70 a year by switching to combi

Please help me decide, should i just replace the clyinder or go for the combi boiler replacement
Paul Benington
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Simply Build It

Postby toneyt » Wed Jun 27, 2007 6:52 pm

most installers now will opt for the combi as they are eaiser to install,nowadays people jsut want instant h/w my old adage is if the boiler breaks down(yes new ones break too )you have no back up,at least with the cylinder & immersion you can have some hot water and put another jumper on to warm up,
if you need the space where the cylinder is and the loft space where the jockey tank/cold water tank is then go for the combi option.
the vaillant is still the best but being caught by worcester look at the gloworm cxi which is the same as the vaillant only different badge although they wont admit it!
Hope this sheds some knowledge let me know if you need more info
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Postby Paul Benington » Thu Jun 28, 2007 9:56 am

Thanks Tony

I'm only considering changing my existing boiler as i need to pull it out to get at the leaking cylinder. My choice is do i spend £700 ish to replace a leaking cylinder and stick with my 5 year old boiler. Or do i 'upgrade' to a combi boiler whilst i'm having work done and install an A rated combi for approx £2500. I still don't know what to do
Paul Benington
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Postby sparx » Thu Jun 28, 2007 7:40 pm

Hi for what its worth, as a leckie who gets to connect lots of various systems it seems to me from customer feed-back that combi's OK for space saving but flow rate for hot water very poor, due to need to heat water instantly so heat exchanger design slows down water through put to give time to heat up sufficiently. Acceptable for sink or one shower but not much pressure so if longer runs or several outlets stick with tank, also as Toneyt says immersion heater good back up,regards SPARX
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Postby plumbers1 » Fri Jun 29, 2007 11:13 pm

I fit Worcester-Bosch boilers only and I LOVE them although a little pricey. Fit a 30cdi combi condensing flow rate 14lts min that should do the trick but best system would be unvented cylinder and system boiler if space is not a problem
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Postby johnb » Fri Jul 13, 2007 3:31 pm

hi , check plumbers-1 he has right idea expensive but good more efficient at storage plus h/water backup via emmersion you may get away with smaller boiler get it sized properly. all the best john
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