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New central heating system required

Postby dobbin » Tue Aug 05, 2008 8:30 am

Ok, gas is now up another 35% and I have decided that my old (20+) Baxi boiler and radiators are having to go and a newer much more efficient system is to be installed. Dilemma, what type of boiler should I go for? I have heard many horror stories about combi boilers failing and requiring new control panels and pressure valves, what makes should I stay well away from and what should I look for with regards functions on the boiler itself, if that makes sense. I wish to have a programmeable room stat controlling the heating side as a minimum and know that since around 2005 any boiler shall be a condensing version. I have done the calculations and estimate that I need a wall mounted boiler vented through the wall of around 80000BTU's or around 20KW. This will feed ten radiators, (3 upstairs and 7 downstairs)probably stelrad elite or compact models (but open minded) via 10mm microbore piping from manifolds being fed via 22mm copper pipe direct from the boiler. Do the new boilers come complete with circulation pumps or like my old boiler did require an external pump.
I priced this lot up the other day using plumbcenters prices and nearly had a heart attack, £5K for boiler and radiators alone.
I have read that combi boilers struggle a bit due to low flow rates to fill a deep bath is this true? what flow rate should I be looking for?
How can some of the local heating companies offer systems at around half this price installed. Are they using inferior materials, poor quality boilers etc, or are they getting better discounts than the man in the street from retailers.
I hope this makes sense,
Any help / advice would be appreciated. :?: :lol:
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Simply Build It

Postby htg engineer » Tue Aug 05, 2008 8:13 pm

Happy with your Baxi Boiler ??? i'd gor for another Baxi. They're cheap to buy and cheap for parts, also easy to repair so labour costs are reasonable. So when it breaks down (all boilers will at some point) it wont break the bank. £5000 way over the top, get a few more quotes, you'll get it done for half that.

80000 BTU's ? you either have small radiators in every room or your calculatiions are wrong. Normally for 10 radiators, you want at least 100,000 BTU's. Also check the flow rate if you're planning on running a shower from it. Assuming you want a combi ?

Baxi do a 33kw (105,000 BTU) boiler, would probably suit you.

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