Boiler and system selection

[Richie866]

Hi guys, this is my first post, so hello and welcome! I was just wondering if anyone could give me some advice on upgrading my heating system. Its currently an open vented system running a small glow worm boiler and a 150l cylinder. The house has been extended on a few occasions, but the old boiler is still there, probably a bit to small now for the house (approx 200m sq with 7 largish rads and 6 small/medium).

I was thinking if replacing the system with a Vaillant HE System boiler and 250l unvented cylinder. Does this sound like a good move, and roughly what size boiler should my plumber be advising for a system of that size/type. (house is IRO 1930 fully D/G, fairly well insulated with 2 bathrooms and a seperate W/C)

Any advice greatly appreciated. And if you could give me an idea of the price that would be even better!

 

[crashndie]

hi mate unvented hot water on conventional boiler is grate idea plenty of stored hot water an at pressure, just remember that your plumber must have his unvented an by rites rules say you must inform your local council (altho dont actualy think anyone dos)

with out seeing what size rads you have or seeing the property id be looking at a minimum of 18 kw and a 24kw will be more than enuff. i quite like the ideal icos or valiant heat only boiler. ive fitted both and never had any problems with them just be sure to get a PROPER power flush aluminum heat exchangers wont last to long if the system isnt flushed and make sure you have inhibitors added to.

hope this helps danny

 

[Agile]

Siunce you are going to be there for some while you should get it right first time.

You need to use the whole house heat loss method to calculate the boiler size. You only need 2 kW added for hot water heating. OVERSIZING is wasteful !

The cylinder should be about 50 li plus 50 li for every person living there up to about five but a 300 will usually manage up to seven if they are not too profligate in their hot water usage.

Tony

 

[Richie866]

thanks guys, thats definately given me some thing to go on-now for the tough bit-getting it done and paying for it!