Which combi boiler

[Josephcoyle]

Hi guys and girls

First time poster to the forum so apologies if this question has been asked.

I am currently doing an extension to my house - going from a 3 bedroom 1 bathroom to a 5 bedroom 3 bathroom (1 Main bathroom, one ensuite and 1 downstairs toilet) house.
We already had gas in the house and are putting in a new combi boiler as the previous one was on its last legs.

Can you give me some advice on
1. Which combi boilers are the best / most reliable on the market
2. How many litres / sec should it be
3. What should the BTU's be.
4. Anything else I need to know.

Apologies for the stupidity but I want to make sure I'm knowledgeable before I approach a plumber / boiler salesman.

Thanks in advance
Joseph

 

[dreadnoughtheating]

I'll kick of the DO NOT GET A COMBI section of the replies.

Even the biggest baddest one would deliver about 16litres/min.

Assuming you have a cold main inlet pipe able to supply that amount.

Check your dynamic pressure AND Flow rate.

A WB highflow/Alpha FLoSmart(?) may just be able to run two basin taps simultaneously, but with that many potential people and that many hot water draw off points likely to be opened at the same time?

I would look at an Unvented cylinder (assuming pressure/flow rates are OK first). Perhaps running the cylinder off the Combi as a separate zone (like a separate heating zone, the combi does not care if it is heating water or air)

just a few thoughts from me, you will get many other opinions I expect

DH

 

[mehran]

get a rinnia twinflow...20 l/m for hot water and high quality boiler for heating.
http://www.rinnaiuk.com/2_Products/1_Twin_Flow/1_Twin_Flow.html

first things first though need to check the cold flow rate in the house. if poor then you need to boost it.

 

[numpty1]

I am currently doing an extension to my house - going from a 3 bedroom 1 bathroom to a 5 bedroom 3 bathroom (1 Main bathroom, one ensuite and 1 downstairs toilet) house.
We already had gas in the house and are putting in a new combi boiler as the previous one was on its last legs.

mehran is on the money with his suggestion of the twinflow.it will easily deal with your requirements,only drawback will be size,it will fit your gas supply and meter without modifications.Hamiltons of bangor can supply them,or if you really want to experience pain plumbs montgomery road

 

[mickyg]

Glow worm ultrapower sxi170. assuming the flow rate is adequate.

 

[bengasman]

No combi will supply 3 bathrooms, unless you are sure at no time all 3 are used at the same time, you are looking at a fair sized unvented cylinder somewhere in the region of 300 litres. That also means that your incoming mains needs to be at the very least 22 mm all the way back to the streetvalve, preferably 32.

 

[mickyg]

No combi will supply 3 bathrooms

Glow worm ultrapower sxi170. assuming the flow rate is adequate.