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Central Heating

thinking of changing our central heating boiler to either worcester 42CDI or 440CDI ?

Anonymous user 14 October 2011 - 2.30 PM

we currently have a worcester floor-standing highflow with its heatbank. So the 440CDI would be similar to what we have at present. But the wife prefers to change to wall-mounted so best is 42CDI. I am worried that we will have problems with the 42CDi not producing the amount of water we are used to. rough test while running downstairs hot tap, bath gave 11 litres in a minute, so are we wasting our money buying a 440CDI to get a flow of 20 litres per minute. normally only maximum of 3 people in this 4-bed semi house. One bathroom, but there is space for a futue en-suite in bedroom 1 and also to extend into loft for a further 2 bedrooms and a second bathroom. if that was ever done surely we would need a bigger boiler, we currently have about 16 rads. we want to stick to worcester but worried about what is best for the long term. any help would be appreciated.

6 answers from MyBuilder tradespeople

Best answer
IAN PRICE PLUMBING&HEATING
Rating: 4.9 out of 54.95109 reviews
Sheffield

HI Both these boilers would suite your needs.The 42cdi will deliver 17.2liters per min the 440 will deliver 20lpm dependant on mains incomming pressure .heating wise the 42 is 30kw capable of 102,300btus the 440 is 29.2kw the same btus price 42cdi a lot cheaper to both buy and install

Answered

17 October 2011

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7
AM heating
Rating: 5 out of 555134 reviews
Bristol

hi there combi boilers will only provide water for one hot tap outlet at a time if multiple outlets are to be needed then you will need water storage ie a pressurised cylinder providing mains pressure hot water. on the other hand how many times are people going to be bathing at the same time so your cheapest option will always be the combi. regards am heating

Answered

17 October 2011

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6

Anonymous user

Hi It would seem u would be wasting ur money On anything more than 20/35 Kw boiler Worc ok but pricey and not user friendly Ideal good alternative Regards ian Combi boiler services

Answered

17 October 2011

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5
NJ Lees plumbing & Heating Ltd
Rating: 5 out of 5554 reviews
Worthing

Hi The test you carried out is not correct for finding out the flow rate There are two things that need to be known to determine flow rate and the best way to do this is via an outside tap that does not have a ballafix valve fitted to it so that you're getting the full flow What you need to find out are your dynamic flow and static pressure then you can decide what combi boiler will best suit your needs From what you say I feel that the best route to go down would be with a system boiler and an unvented cylinder but this will depend upon the water flow rate and static pressure Hope this helps Neal

Answered

17 October 2011

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5
PAUL CATON GAS & OIL SERVICES LTD
PAUL CATON GAS & OIL SERVICES LTD
Rating: 5 out of 555615 reviews
Chesterfield

You would be better with a system boiler and a unvented cylinder to get the high flow rates

Answered

16 October 2011

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3
Lambert Plumbing & Heating Ltd
Rating: 5 out of 555243 reviews
Carshalton

You have quite a few variables in this question. The boiler and system should be sized to the property and potential demand not the amount of people that may or may not be staying their. The flow rate and pressure would need to be looked at (you can only get out what you've got going in) Definitely get some quotes and see what the engineers have to say. You would want them to do a heat loss calculation for your property taking in to consideration future extensions which will then tell you if your proposed boiler will be able to handle the extra heating demand An over sized boiler will modulate (fire to the required demand) but would not be as economical as if it was correctly sized as this would condense for longer periods getting you more for your gas I would say that your current set up could do with a different solution to be satisfactory with your proposed extensions, ideally a boiler that you can range rate and maybe an unvented cylinder. Kind regards Terry

Answered

17 October 2011

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3